A Mediterranean diet not only boosts health, but also improves fertility

December 13, 2022

Science Daily/University of South Australia

With an emphasis on fruits, vegetables and legumes, the Mediterranean diet has long been applauded for its multiple health benefits. Now, new research shows that it may also help overcome infertility, making it a non-intrusive and affordable strategy for couples trying to conceive.

Conducted by Monash University, the University of the Sunshine Coast, and the University of South Australia, the review found that the Mediterranean diet can improve fertility, assisted reproductive technology (ART) success, and sperm quality in men.

Specifically, researchers identified that the anti-inflammatory properties of a Mediterranean diet can improve couples' chances of conception.

Infertility is a global health concern affecting 48 million couples and 186 million individuals worldwide.

UniSA researcher, Dr Evangeline Mantzioris, says modifying preconception nutrition is a non-invasive and potentially effective means for improving fertility outcomes.

"Deciding to have a baby is one of life's biggest decisions, but if things don't go as planned, it can be very stressful for both partners," Dr Mantzioris says.

"Research shows inflammation can affect fertility for both men and women, affecting sperm quality, menstrual cycles, and implantation. So, in this study we wanted to see how a diet that reduces inflammation -- such as the Mediterranean diet -- might improve fertility outcomes.

"Encouragingly, we found consistent evidence that by adhering to an anti-inflammatory diet -- one that includes lots of polyunsaturated or 'healthy' fats, flavonoids (such as leafy green vegetables), and a limited amount of red and processed meat -- we can improve fertility."

The Mediterranean diet is primarily plant-based, and includes whole grains, extra virgin olive oil, fruits, vegetables, beans and legumes, nuts, herbs, and spices. Yoghurt, cheese, and lean protein sources such as fish, chicken, or eggs; red and processed meats are only eaten in small amounts.

In comparison, a western diet comprises excessive saturated fats, refined carbohydrates, and animal proteins, making it energy-dense and lacking dietary fibre, vitamins, and minerals. Typically, a western diet is associated with higher levels of inflammation.

Monash University researcher, Simon Alesi, says understanding the association between anti-inflammatory diets such as the Mediterranean diet, and fertility, could be a gamechanger for couples hoping to start a family.

"The Mediterranean diet is consistently ranked among the healthiest diets in the world. But knowing that it may also boost your chances of conceiving and having a baby is extremely promising," Alesi says.

"Modifying your diet is a non-intrusive and affordable strategy that could potentially improve infertility.

"Of course, more research needs to be done, but at the very least, shifting to a Mediterranean diet will not only improve your overall health, but also your chances of conceiving."

https://www.sciencedaily.com/releases/2022/12/221213094801.htm

Scientists discover secret to waking up alert and refreshed

Takeaway: Sleep longer and later, get exercise the day before, eat a low sugar, high carb breakfast

November 29, 2022

Science Daily/University of California - Berkeley

Do you feel groggy until you've had your morning coffee? Do you battle sleepiness throughout the workday?

You're not alone. Many people struggle with morning alertness, but a new study demonstrates that awaking refreshed each day is not just something a lucky few are born with. Scientists at the University of California, Berkeley, have discovered that you can wake up each morning without feeling sluggish by paying attention to three key factors: sleep, exercise and breakfast.

The findings come from a detailed analysis of the behavior of 833 people who, over a two-week period, were given a variety of breakfast meals; wore wristwatches to record their physical activity and sleep quantity, quality, timing and regularity; kept diaries of their food intake; and recorded their alertness levels from the moment they woke up and throughout the day. Twins -- identical and fraternal -- were included in the study to disentangle the influence of genes from environment and behavior.

The researchers found that the secret to alertness is a three-part prescription requiring substantial exercise the previous day, sleeping longer and later into the morning, and eating a breakfast high in complex carbohydrates, with limited sugar. The researchers also discovered that a healthy controlled blood glucose response after eating breakfast is key to waking up more effectively.

"All of these have a unique and independent effect," said UC Berkeley postdoctoral fellow Raphael Vallat, first author of the study. "If you sleep longer or later, you're going to see an increase in your alertness. If you do more physical activity on the day before, you're going to see an increase. You can see improvements with each and every one of these factors."

Morning grogginess is more than just an annoyance. It has major societal consequences: Many auto accidents, job injuries and large-scale disasters are caused by people who cannot shake off sleepiness. The Exxon Valdez oil spill in Alaska, the Three Mile Island nuclear meltdown in Pennsylvania and an even worse nuclear accident in Chernobyl, Ukraine, are well-known examples.

"Many of us think that morning sleepiness is a benign annoyance. However, it costs developed nations billions of dollars every year through loss of productivity, increased health care utilization, work absenteeism. More impactful, however, is that it costs lives -- it is deadly," said senior author Matthew Walker, UC Berkeley professor of neuroscience and psychology. "From car crashes to work-related accidents, the cost of sleepiness is deadly. As scientists, we must understand how to help society wake up better and help reduce the mortal cost to society's current struggle to wake up effectively each day."

Vallat, Walker and their colleagues published their findings last week in the journal Nature Communications. Walker, the author of the international bestseller, Why We Sleep, runs one of the world's preeminent sleep research labs, the Center for Human Sleep Science, and is a member of the Helen Wills Neuroscience Institute at UC Berkeley.

A personalized approach to eating

Walker and Vallat teamed up with researchers in the United Kingdom, the U.S and Sweden to analyze data acquired by a U.K. company, Zoe Ltd., that has followed hundreds of people for two-week periods in order to learn how to predict individualized metabolic responses to foods based on a person's biological characteristics, lifestyle factors and the foods' nutritional composition.

The participants were given preprepared meals, with different amounts of nutrients incorporated into muffins, for the entire two weeks to see how they responded to different diets upon waking. A standardized breakfast, with moderate amounts of fat and carbohydrates, was compared to a high protein (muffins plus a milkshake), high carbohydrate or high sugar (glucose drink) breakfast. The subjects also wore continuous glucose monitors to measure blood glucose levels throughout the day.

The worst type of breakfast, on average, contained high amounts of simple sugar; it was associated with an inability to wake up effectively and maintain alertness. When given this sugar-infused breakfast, participants struggled with sleepiness.

In contrast, the high carbohydrate breakfast -- which contained large amounts of carbohydrates, as opposed to simple sugar, and only a modest amount of protein -- was linked to individuals revving up their alertness quickly in the morning and sustaining that alert state.

"A breakfast rich in carbohydrates can increase alertness, so long as your body is healthy and capable of efficiently disposing of the glucose from that meal, preventing a sustained spike in blood sugar that otherwise blunts your brain's alertness," Vallat said

"We have known for some time that a diet high in sugar is harmful to sleep, not to mention being toxic for the cells in your brain and body," Walker added. "However, what we have discovered is that, beyond these harmful effects on sleep, consuming high amounts of sugar in your breakfast, and having a spike in blood sugar following any type of breakfast meal, markedly blunts your brain's ability to return to waking consciousness following sleep."

It wasn't all about food, however. Sleep mattered significantly. In particular, Vallat and Walker discovered that sleeping longer than you usually do, and/or sleeping later than usual, resulted in individuals ramping up their alertness very quickly after awakening from sleep. According to Walker, between seven and nine hours of sleep is ideal for ridding the body of "sleep inertia," the inability to transition effectively to a state of functional cognitive alertness upon awakening. Most people need this amount of sleep to remove a chemical called adenosine that accumulates in the body throughout the day and brings on sleepiness in the evening, something known as sleep pressure.

"Considering that the majority of individuals in society are not getting enough sleep during the week, sleeping longer on a given day can help clear some of the adenosine sleepiness debt they are carrying," Walker speculated.

"In addition, sleeping later can help with alertness for a second reason," he said. "When you wake up later, you are rising at a higher point on the upswing of your 24-hour circadian rhythm, which ramps up throughout the morning and boosts alertness."

It's unclear, however, what physical activity does to improve alertness the following day.

"It is well known that physical activity, in general, improves your alertness and also your mood level, and we did find a high correlation in this study between participants' mood and their alertness levels," Vallat said. "Participants that, on average, are happier also feel more alert."

But Vallat also noted that exercise is generally associated with better sleep and a happier mood.

"It may be that exercise-induced better sleep is part of the reason exercise the day before, by helping sleep that night, leads to superior alertness throughout the next day," Vallat said.

Walker noted that the restoration of consciousness from non-consciousness -- from sleep to wake -- is unlikely to be a simple biological process.

"If you pause to think, it is a non-trivial accomplishment to go from being nonconscious, recumbent and immobile to being a thoughtful, conscious, attentive and productive human being, active, awake, and mobile. It's unlikely that such a radical, fundamental change is simply going to be explained by tweaking one single thing," he said. "However, we have discovered that there are still some basic, modifiable yet powerful ingredients to the awakening equation that people can focus on -- a relatively simple prescription for how best to wake up each day."

It's not in your genes

Comparisons of data between pairs of identical and non-identical twins showed that genetics plays only a minor and insignificant role in next-day alertness, explaining only about 25% of the differences across individuals.

"We know there are people who always seem to be bright-eyed and bushy-tailed when they first wake up," Walker said. "But if you're not like that, you tend to think, 'Well, I guess it's just my genetic fate that I'm slow to wake up. There's really nothing I can do about it, short of using the stimulant chemical caffeine, which can harm sleep.

"But our new findings offer a different and more optimistic message. How you wake up each day is very much under your own control, based on how you structure your life and your sleep. You don't need to feel resigned to any fate, throwing your hands up in disappointment because, '… it's my genes, and I can't change my genes.' There are some very basic and achievable things you can start doing today, and tonight, to change how you awake each morning, feeling alert and free of that grogginess."

Walker, Vallat and their colleagues continue their collaboration with the Zoe team, examining novel scientific questions about how sleep, diet and physical exercise change people's brain and body health, steering them away from disease and sickness.

https://www.sciencedaily.com/releases/2022/11/221129143811.htm

Dieters may overestimate the healthiness of their eating habits

November 1, 2022

Science Daily/American Heart Association

In a small study, most adults seeking to lose weight overestimated the healthiness of their diet, according to preliminary research to be presented at the American Heart Association's Scientific Sessions 2022. The meeting, held in person in Chicago and virtually, Nov. 5-7, 2022, is a premier global exchange of the latest scientific advancements, research and evidence-based clinical practice updates in cardiovascular science.

"We found that while people generally know that fruits and vegetables are healthy, there may be a disconnect between what researchers and health care professionals consider to be a healthy and balanced diet compared to what the public thinks is a healthy and balanced diet," said study author Jessica Cheng, Ph.D., a postdoctoral research fellow in epidemiology at the Harvard T. H. Chan School of Public Health and in general internal medicine at Massachusetts General Hospital, both in Boston. This research was conducted while Dr. Cheng was a predoctoral fellow/Ph.D. candidate in the department of epidemiology at the University of Pittsburgh School of Public Health.

Nearly half of adults in the U.S. try to lose weight each year, according to the Centers for Disease Control and Prevention, with a majority attempting to eat more fruits, vegetables and salads. Healthy eating is essential for heart and general health, and longevity. Dietary guidance from the American Heart Association issued in 2021 advises adults to eat a variety of fruits and vegetables; opt for whole grains rather than refined grains; choose healthy protein sources; substitute nonfat and low-fat dairy products for full-fat versions; choose lean cuts of meat (for those who eat meat); use liquid plant oils instead of tropical oils and animal fats; choose minimally processed over ultra-processed foods; minimize foods and beverages with added sugar; choose foods with little or no added salt; and limit or avoid alcohol.

Researchers evaluated the diets of 116 adults aged 35-58 years old in the greater Pittsburgh, PA, area who were trying to lose weight. Study participants met one-on-one with a dietitian to discuss their nutrition and then tracked everything they ate and drank every day for one year on the Fitbit app. They also weighed themselves daily and wore a Fitbit device to track their physical activity.

Researchers calculated a Healthy Eating Index (HEI) score at the beginning and end of the study based on the types of foods that participants reported eating. Participants were asked to complete a 24-hour food recall for two days at each time point. The HEI is a measure for assessing how closely a dietary pattern aligns with the U.S. government's Dietary Guidelines for Americans. A score of 0 to 100 is possible, with a higher score indicating a healthier diet. The score is based on the frequency of eating various dietary components such fruits, vegetables, whole and refined grains, meat and seafood, sodium, fats and sugars.

Participants self-scored their beginning and ending diet quality to determine their perceived scores. Their scores were also on a 0-100 scale based on the components of the HEI. The self-assessment of their beginning diet was a "look back" as they scored both their starting and ending diets at the end of the study. The difference in their starting and ending score was their perceived diet change. A difference of 6 points or less between the researchers' HEI score and the participant's perceived score was considered "good agreement."

At the end of the study, about 1 in 4 participants' scores had good agreement between their perceived diet score and the researcher-assessed score. The remaining 3 out of 4 participants' scores had poor agreement, and most reported a perceived score that was higher than the HEI score assigned by researchers. The average perceived score was 67.6, and the average HEI score was 56.4.

In judging the change in diet score over 12 months, only 1 in 10 participants had good agreement between their self-assessed change compared to the change in the researchers' HEI score. At the end of the study, participants improved their diet quality by about one point based on the researcher-assessed score. However, participants' self-estimate was a perceived 18-point improvement.

"People attempting to lose weight or health professionals who are helping people with weight loss or nutrition-related goals should be aware that there is likely more room for improvement in the diet than may be expected," said Cheng. She suggests providing concrete information on what areas of their diet can be improved and how to go about making healthy, sustainable nutrition changes.

"Future studies should examine the effects of helping people close the gap between their perceptions and objective diet quality measurements," she said.

"Overestimating the perceived healthiness of food intake could lead to weight gain, frustrations over not meeting personal weight loss goals or lower likelihood of adopting healthier eating habits," said Deepika Laddu, Ph.D., an assistant professor in the College of Applied Health Sciences at the University of Illinois, Chicago, and chair of the American Heart Association's Council on Lifestyle Behavioral Change for Improving Health Factors. "While misperception of diet intake is common among dieters, these findings provide additional support for behavioral counselling interventions that include more frequent contacts with health care professionals, such as dieticians or health coaches, to address the gaps in perception and support long-lasting, realistic healthy eating behaviors."

Among the study's limitations are that participants were mostly female (79%) and the majority reported white race (84%), so the findings may not apply in the same ways to other populations. In addition, the researchers assessed diet quality perceptions only at the end of the study. Assessments throughout the study may have helped to answer questions, such as whether perception became more realistic over the course of the study or whether a person's perception of their diet helps or hinders them from making dietary changes.

https://www.sciencedaily.com/releases/2022/11/221101111724.htm

Daytime eating may benefit mental health

A study on meal timing found that eating at night increased depression and anxiety-related mood levels among participants

September 12, 2022

Science Daily/Brigham and Women's Hospital

Investigators have designed a study that simulated night work and then tested the effects of daytime and nighttime eating versus daytime eating only. The team found that, among participants in the daytime and nighttime eating group, depression-like mood levels increased by 26 percent and anxiety-like mood levels by 16 percent. Participants in the daytime-only eating group did not experience this increase, suggesting that meal timing may influence mood vulnerability.

Beating the blues with food? A new study adds evidence that meal timing may affect mental health, including levels of depression- and anxiety-related mood. Investigators from Brigham and Women's Hospital, a founding member of the Mass General Brigham healthcare system, designed a study that simulated night work and then tested the effects of daytime and nighttime eating versus daytime eating only. The team found that, among participants in the daytime and nighttime eating group, depression-like mood levels increased by 26 percent and anxiety-like mood levels by 16 percent. Participants in the daytime-only eating group did not experience this increase, suggesting that meal timing may influence mood vulnerability. Results are published in the Proceedings of the National Academy of Sciences.

"Our findings provide evidence for the timing of food intake as a novel strategy to potentially minimize mood vulnerability in individuals experiencing circadian misalignment, such as people engaged in shift work, experiencing jet lag, or suffering from circadian rhythm disorders," said co-corresponding author Frank A. J. L. Scheer, PhD, Director of the Medical Chronobiology Program in the Brigham's Division of Sleep and Circadian Disorders. "Future studies in shift workers and clinical populations are required to firmly establish if changes in meal timing can prevent their increased mood vulnerability. Until then, our study brings a new 'player' to the table: the timing of food intake matters for our mood."

Shift workers account for up to 20 percent of the workforce in industrial societies and are directly responsible for many hospital services, factory work, and other essential services. Shift workers often experience a misalignment between their central circadian clock in the brain and daily behaviors, such as sleep/wake and fasting/eating cycles. Importantly, they also have a 25 to 40 percent higher risk of depression and anxiety.

"Shift workers -- as well as individuals experiencing circadian disruption, including jet lag -- may benefit from our meal timing intervention," said co-corresponding author Sarah L. Chellappa, MD, PhD, who completed work on this project while at the Brigham. Chellappa is now in the Department of Nuclear Medicine, University of Cologne, Germany. "Our findings open the door for a novel sleep/circadian behavioral strategy that might also benefit individuals experiencing mental health disorders. Our study adds to a growing body of evidence finding that strategies that optimize sleep and circadian rhythms may help promote mental health."

To conduct the study, Scheer, Chellappa, and colleagues enrolled 19 participants (12 men and 7 women) for a randomized controlled study. Participants underwent a Forced Desynchrony protocol in dim light for four 28-hour "days," such that by the fourth "day" their behavioral cycles were inverted by 12 hours, simulating night work and causing circadian misalignment. Participants were randomly assigned to one of two meal timing groups: the Daytime and Nighttime Meal Control Group, which had meals according to a 28-hour cycle (resulting in eating both during the night and day, which is typical among night workers), and the Daytime-Only Meal Intervention Group, which had meals on a 24-hour cycle (resulting in eating only during the day). The team assessed depression- and anxiety-like mood levels every hour.

The team found that meal timing significantly affected the participants' mood levels. During the simulated night shift (day 4), those in the Daytime and Nighttime Meal Control Group had increased depression-like mood levels and anxiety-like mood levels, compared to baseline (day 1). In contrast, there were no changes in mood in the Daytime Meal Intervention Group during the simulated night shift. Participants with a greater degree of circadian misalignment experienced more depression- and anxiety-like mood.

"Meal timing is emerging as an important aspect of nutrition that may influence physical health," said Chellappa. "But the causal role of the timing of food intake on mental health remains to be tested. Future studies are required to establish if changes in meal timing can help individuals experiencing depressive and anxiety/anxiety-related disorders."

https://www.sciencedaily.com/releases/2022/09/220912152846.htm

Cravings for fatty foods traced to gut-brain connection

Mouse research reveals fat sensors in the intestines that stimulate the brain and drive food desires

September 7, 2022

Science Daily/Columbia University

A dieter wrestling with cravings for fatty foods might be tempted to blame their tongue: the delicious taste of butter or ice cream is hard to resist. But new research investigating the source of our appetites has uncovered an entirely new connection between the gut and the brain that drives our desire for fat.

At Columbia's Zuckerman Institute, scientists studying mice found that fat entering the intestines triggers a signal. Conducted along nerves to the brain, this signal drives a desire for fatty foods. Published September 7, 2022, in Nature, the new study raises the possibility of interfering with this gut-brain connection to help prevent unhealthy choices and address the growing global health crisis caused by overeating.

"We live in unprecedented times, in which the overconsumption of fats and sugars is causing an epidemic of obesity and metabolic disorders," said first author Mengtong Li, PhD, a postdoctoral researcher in the lab of the Zuckerman Institute's Charles Zuker, PhD, supported by the Howard Hughes Medical Institute. "If we want to control our insatiable desire for fat, science is showing us that the key conduit driving these cravings is a connection between the gut and the brain."

This new view of dietary choices and health started with previous work from the Zuker lab on sugar. Researchers found that glucose activates a specific gut-brain circuit that communicates to the brain in the presence of intestinal sugar. Calorie-free artificial sweeteners, in contrast, do not have this effect, likely explaining why diet sodas can leave us feeling unsatisfied.

"Our research is showing that the tongue tells our brain what we like, such as things that taste sweet, salty or fatty," said Dr. Zuker, who is also a professor of biochemistry and molecular biophysics and of neuroscience at Columbia's Vagelos College of Physicians and Surgeons. "The gut, however, tells our brain what we want, what we need."

Dr. Li wanted to explore how mice respond to dietary fats: the lipids and fatty acids that every animal must consume to provide the building blocks of life. She offered mice bottles of water with dissolved fats, including a component of soybean oil, and bottles of water containing sweet substances known to not affect the gut but that are initially attractive. The rodents developed a strong preference, over a couple of days, for the fatty water. They formed this preference even when the scientists genetically modified the mice to remove the animals' ability to taste fat using their tongues.

"Even though the animals could not taste fat, they were nevertheless driven to consume it," said Dr. Zuker.

The researchers reasoned that fat must be activating specific brain circuits driving the animals' behavioral response to fat. To search for that circuit, Dr. Li measured brain activity in mice while giving the animals fat. Neurons in one particular region of the brainstem, the caudal nucleus of the solitary tract (cNST), perked up. This was intriguing because the cNST was also implicated in the lab's previous discovery of the neural basis of sugar preference.

Dr. Li then found the communications lines that carried the message to the cNST. Neurons in the vagus nerve, which links the gut to the brain, also twittered with activity when mice had fat in their intestines.

Having identified the biological machinery underlying a mouse's preference for fat, Dr. Li next took a close look at the gut itself: specifically the endothelial cells lining the intestines. She found two groups of cells that sent signals to the vagal neurons in response to fat.

"One group of cells functions as a general sensor of essential nutrients, responding not only to fat, but also to sugars and amino acids," said Dr. Li. "The other group responds to only fat, potentially helping the brain distinguish fats from other substances in the gut."

Dr. Li then went one important step further by blocking the activity of these cells using a drug. Shutting down signaling from either cell group prevented vagal neurons from responding to fat in the intestines. She then used genetic techniques to deactivate either the vagal neurons themselves or the neurons in the cNST. In both cases, a mouse lost its appetite for fat.

"These interventions verified that each of these biological steps from the gut to the brain is critical for an animal's response to fat," said Dr. Li. "These experiments also provide novel strategies for changing the brain's response to fat and possibly behavior toward food."

The stakes are high. Obesity rates have nearly doubled worldwide since 1980. Today, nearly half a billion people suffer from diabetes.

"The overconsumption of cheap, highly processed foods rich in sugar and fat is having a devastating impact on human health, especially among people of low income and in communities of color," said Dr. Zuker. "The better we understand how these foods hijack the biological machinery underlying taste and the gut-brain axis, the more opportunity we will have to intervene."

Scott Sternson, PhD, a professor of neuroscience at University of California, San Diego, who was not involved in the new research highlighted its potential for improving human health.

"This exciting study offers insight about the molecules and cells that compel animals to desire fat," said Dr. Sternson, whose work focuses on how the brain controls appetite. "The capability of researchers to control this desire may eventually lead to treatments that may help combat obesity by reducing consumption of high-calorie fatty foods."

https://www.sciencedaily.com/releases/2022/09/220907133226.htm

New insights on how some individuals with obesity can lose weight -- and keep it off

August 11, 2022

Science Daily/University of Ottawa

For decades, there's been a persistent one-size-fits-all approach to treating obesity: Embrace a diet that's low in calories. Yet evidence shows that this diet-focused approach simply doesn't work for a subset of adults with obesity who are adherent in a clinical weight management program.

Now, compelling new research published in the journal eBioMedicine challenges the deeply ingrained idea that diet alone should be adequate for everyone seeking to shed pounds.

The important conclusions could significantly improve public health by guiding the advent of personalized treatment plans that will help individuals with difficult-to-treat obesity lose weight -- and keep it off.

"It's exciting and important work. These findings have clinical implications and reveal molecular mechanisms that will drive research for many years to come," says Dr. Mary-Ellen Harper, an award-winning professor and research chair in mitochondrial bioenergetics at the uOttawa Faculty of Medicine who was the study's senior author.

Understanding distinct obesity phenotypes is key to teasing out insights into individual variations in weight loss. And for "diet-resistant" obesity -- patients in the bottom 20% for rate of weight loss following a low-calorie diet -- exercise training should be prioritized, as it decreases fat mass and boosts skeletal muscle metabolism.

The research team mined clinical data from over 5,000 records. Ultimately, 228 files were reviewed and a subset of 20 women with obesity were identified to undergo a closely supervised exercise program made up of 18 progressive sessions using treadmills and weights done three times per week for six weeks.

Using bioinformatics and machine learning approaches to analyze skeletal muscle, the results indicate that exercise preferentially improves skeletal muscle metabolism and enhances weight loss capacity for individuals with obesity who are deemed diet resistant.

These are the type of patients with difficult-to-treat obesity who have often been accused of non-adherence when they have not lost weight with diet restriction.

"For those individuals who have obesity and who've had enormous difficulty losing weight, the message for them is: You are in a group of individuals for whom exercise is particularly important. And that's really going to help you lose weight," says Dr. Ruth McPherson, a leader in cardiovascular genetics who is a professor at the uOttawa Faculty of Medicine and director of the Ruddy Canadian Cardiovascular Genetics Centre, Atherogenomics Laboratory and the Lipid Clinic at the Ottawa Heart Institute.

The stakes are high: The number of people who are overweight or obese has grown to epidemic proportions globally and obesity is a risk factor in a slew of chronic diseases. In Canada, two out of every three adults are overweight or obese, according to Statistics Canada.

Dr. Robert Dent, founder of the Ottawa Hospital's weight management clinic and an endocrinologist at uOttawa, described the findings as the "crowning glory" of the research work done alongside Drs. Harper and McPherson over two decades. The three partners have collaborated on numerous projects over the years, helping to unlock mysteries of mitochondrial energetics and the genetic predictors of weight loss.

"If you look at a large group of people who are overweight and trying to lose weight, they don't respond to exercise very much. But now we've found that people in this [diet-resistant] obesity phenotype really do," Dr. Dent says. "What the findings are telling us is that when we see individuals with obesity who don't respond to dietary restriction, they should be shunted over to physical activity."

The study has the potential to help reshape the science of weight-loss programs so they can be customized for individual patients. And since the study opens up various exciting research possibilities at the molecular level, the team is already recruiting for a study with a larger sample size.

https://www.sciencedaily.com/releases/2022/08/220811135349.htm

Insufficient sleep in teenagers is associated with overweight and obesity

August 24, 2022

Science Daily/European Society of Cardiology

Adolescents who sleep less than eight hours a night are more likely to be overweight or obese compared to their peers with sufficient sleep,according to research presented at ESC Congress 2022. Shorter sleepers were also more likely to have a combination of other unhealthy characteristics including excess fat around the middle, elevated blood pressure, and abnormal blood lipid and glucose levels.

"Our study shows that most teenagers do not get enough sleep and this is connected with excess weight and characteristics that promote weight gain, potentially setting them up for future problems," said study author Mr. Jesús Martínez Gómez, a researcher in training at the Cardiovascular Health and Imaging Laboratory, Spanish National Centre for Cardiovascular Research (CNIC), Madrid, Spain. "We are currently investigating whether poor sleep habits are related to excessive screen time, which could explain why older adolescents get even less sleep than younger ones."

This study examined the association between sleep duration and health in 1,229 adolescents in the SI! Program for Secondary Schools trial in Spain. Participants had an average age of 12 years at baseline with equal numbers of boys and girls.

Sleep was measured for seven days with a wearable activity tracker three times in each participant at ages 12, 14 and 16 years. For optimal health, the American Academy of Sleep Medicine advises sleeping 9 to 12 hours a night for 6 to 12 year-olds and 8 to 10 hours for 13 to 18 year-olds. To simplify the analysis, the study used 8 hours or more as optimal. Participants were categorised as very short sleepers (less than 7 hours), short sleepers (7 to 8 hours), and optimal (8 hours or more).

Overweight and obesity were determined according to body mass index. The researchers calculated a continuous metabolic syndrome score ranging from negative (healthier) to positive (unhealthier) values that included waist circumference, blood pressure, and blood glucose and lipid levels.

At 12 years of age, only 34% of participants slept at least 8 hours a night, and this dropped to 23% and 19% at 14 and 16 years of age, respectively. Boys tended to get less sleep. Teenagers who got the most sleep also had better quality sleep, meaning they woke up less during the night and spent a higher proportion of the time in bed sleeping compared to those with shorter sleep. The prevalence of overweight/obesity was 27%, 24% and 21% at 12, 14 and 16 years of age, respectively.

Associations between sleep duration, overweight/obesity and metabolic syndrome score were analysed after adjusting for parental education, migrant status, moderate-to-vigorous physical activity, smoking status, energy intake, city (Madrid or Barcelona) and school.

Compared with optimal sleepers, overweight/obesity was 21% and 72% more likely in very short sleepers at 12 and 14 years, respectively. Short sleepers were 19% and 29% more likely to be overweight/obese compared with optimal sleepers at 12 and 14 years, respectively. Similarly, both very short and short sleepers had higher average metabolic syndrome scores at 12 and 14 years compared with optimal sleepers.

Mr. Martínez Gómez said: "The connections between insufficient sleep and adverse health were independent of energy intake and physical activity levels, indicating that sleep itself is important. Excess weight and metabolic syndrome are ultimately associated with cardiovascular diseases, suggesting that health promotion programmes in schools should teach good sleep habits. Parents can set a good example by having a consistent bedtime and limiting screen time in the evening. Public policies are also needed to tackle this global health problem."

https://www.sciencedaily.com/releases/2022/08/220824102909.htm

Eating more ultra-processed foods associated with increased risk of dementia

July 27, 2022

Science Daily/American Academy of Neurology

People who eat the highest amounts of ultra-processed foods like soft drinks, chips and cookies may have a higher risk of developing dementia than those who eat the lowest amounts, according to a new study published in the July 27, 2022, online issue of Neurology®, the medical journal of the American Academy of Neurology. Researchers also found that replacing ultra-processed foods in a person's diet with unprocessed or minimally processed foods was associated with a lower risk. The study does not prove that ultra-processed foods cause dementia. It only shows an association.

Ultra-processed foods are high in added sugar, fat and salt, and low in protein and fiber. They include soft drinks, salty and sugary snacks, ice cream, sausage, deep-fried chicken, yogurt, canned baked beans and tomatoes, ketchup, mayonnaise, packaged guacamole and hummus, packaged breads and flavored cereals.

"Ultra-processed foods are meant to be convenient and tasty, but they diminish the quality of a person's diet," said study author Huiping Li, PhD, of Tianjin Medical University in China. "These foods may also contain food additives or molecules from packaging or produced during heating, all of which have been shown in other studies to have negative effects on thinking and memory skills. Our research not only found that ultra-processed foods are associated with an increased risk of dementia, it found replacing them with healthy options may decrease dementia risk."

For the study, researchers identified 72,083 people from the UK Biobank, a large database containing the health information of half a million people living in the United Kingdom. Participants were age 55 and older and did not have dementia at the start of the study. They were followed for an average of 10 years. By the end of the study, 518 people were diagnosed with dementia.

During the study, participants filled out at least two questionnaires about what they ate and drank the previous day. Researchers determined how much ultra-processed food people ate by calculating the grams per day and comparing it to the grams per day of other foods to create a percentage of their daily diet. They then divided participants into four equal groups from lowest percentage consumption of ultra-processed foods to highest.

On average, ultra-processed foods made up 9% of the daily diet of people in the lowest group, an average of 225 grams per day, compared to 28% for people in the highest group, or an average of 814 grams per day. One serving of items like pizza or fish sticks was equivalent to 150 grams. The main food group contributing to high ultra-processed food intake was beverages, followed by sugary products and ultra-processed dairy.

In the lowest group, 105 of the 18,021 people developed dementia, compared to 150 of the 18,021 people in the highest group.

After adjusting for age, gender, family history of dementia and heart disease and other factors that could affect risk of dementia, researchers found that for every 10% increase in daily intake of ultra-processed foods, people had a 25% higher risk of dementia.

Researchers also used study data to estimate what would happen if a person substituted 10% of ultra-processed foods with unprocessed or minimally processed foods, like fresh fruit, vegetables, legumes, milk and meat. They found that such a substitution was associated with a 19% lower risk of dementia.

"Our results also show increasing unprocessed or minimally processed foods by only 50 grams a day, which is equivalent to half an apple, a serving of corn, or a bowl of bran cereal, and simultaneously decreasing ultra-processed foods by 50 grams a day, equivalent to a chocolate bar or a serving of fish sticks, is associated with 3% decreased risk of dementia," said Li. "It's encouraging to know that small and manageable changes in dietmay make a difference in a person's risk of dementia."

Li noted that further research is needed to confirm the findings.

Maura E. Walker, PhD, of Boston University in Massachusetts, who wrote an editorial accompanying the study, said, "While nutrition research has started to focus on food processing, the challenge is categorizing such foods as unprocessed, minimally processed, processed and ultra-processed. For example, foods like soup would be classified differently if canned versus homemade. Plus, the level of processing is not always aligned with diet quality. Plant-based burgers that qualify as high quality may also be ultra-processed. As we aim to understand better the complexities of dietary intake, we must also consider that more high-quality dietary assessments may be required."

A limitation of the study was that cases of dementia were determined by looking at hospital records and death registries rather than primary care data, so milder cases may have been overlooked. .

https://www.sciencedaily.com/releases/2022/07/220727163045.htm

A new low-calorie sweetener could also improve gut health

August 4, 2022

Science Daily/American Chemical Society

From the wide variety of sodas, candies and baked goods that are sold worldwide, it's clear that people love their sweet treats. But consuming too much white table sugar or artificial sweetener can lead to health issues. In the search for a better sweetener, researchers in ACS' Journal of Agricultural and Food Chemistry now report a low-calorie mixture that is as sweet as table sugar and, in lab experiments, feeds "good" gut microbes.

Artificial sweeteners have exploded in popularity because they let people consume sweets without the calories. However, while they're considered safe for human consumption, studies in animals and humans suggest that some of them can stimulate appetite, leading to increased food consumption and weight gain, as well as other negative health outcomes. So, researchers have been turning to the study of low-calorie or extremely sweet substances from natural sources as possible replacements. For example, galactooligosaccharides -- found in mammalian milk -- are low-calorie sugars with prebiotic activity that can be a source of energy for beneficial gut microbes, but they're not quite sweet enough to replace table sugar. Alternatively, extracts from the luo han guo fruit contain mogrosides -- compounds 200 to 300 times sweeter than table sugar. But these extracts sometimes have off-flavors, which can be removed with enzymes. So, F. Javier Moreno and colleagues wanted to take advantage of the best aspects of both natural substances, using enzymes to modify mogrosides while simultaneously producing galactooligosaccharides for a brand-new low-calorie sweetener.

The researchers started with lactose and mogroside V (the primary mogrosidein luo han guo fruit). When they added β-galactosidase enzymes, the researchers obtained a mixture that contained mostly galactooligosaccharides and a small amount of modified mogrosides. A trained sensory panel reported that the new combination had a sweetness similar to that of sucrose (table sugar), suggesting it could be acceptable to consumers. In test tube experiments, the new sweetener increased the levels of multiple human gut microbes that are beneficial, including Bifidobacteriumand Lactobacillus bacterial species. In addition, increases in bacteria-produced metabolites, such as acetate, propionate and butyrate, indicated that the mixture could potentially have a prebiotic effect on the gut microbiome. The researchers say that the new sweetener holds promise in these initial analyses, and their next step is to more closely study the substance's impact on human gut health.

https://www.sciencedaily.com/releases/2022/08/220804130631.htm

Circadian clocks play a key role in fat cell growth

August 8, 2022

Science Daily/Weill Cornell Medicine

Disruption of the circadian clocks that keep the body and its cells entrained to the 24-hour day-night cycle plays a critical role in weight gain, according to a pair of studies by Weill Cornell Medicine investigators.

One study, published June 27, in Cell Reports revealed that stress caused by chronically administering glucocorticoid stress hormones and disturbing the normal daily cycle of release triggers a temporary protective mechanism in mice. This mechanism boosts fat cell growth and insulin production while reducing excess blood sugar and fat levels in the bloodstream and liver. The second study, published Aug. 8 in the Proceedings of the National Academies of Sciences, shows that fat cell precursors commit to becoming fat cells during the rest period of mice. The studies suggest that stress and other factors that throw the body's "clocks" out of rhythm may contribute to weight gain and suggest new treatment approaches for obesity.

"A lot of forces are working against a healthy metabolism when we are out of circadian rhythm," explained the senior author of both studies Dr. Mary Teruel, associate professor of biochemistry and a member of the Gale and Ira Drukier Institute for Children's Health at Weill Cornell Medicine. "The more we understand, the more likely we will be able to do something about it."

In the first study, Dr. Teruel and colleagues mimicked the disruptive effects conditions like Cushing's disease or chronic stress have on the usual daily fluctuations in glucocorticoids, a class of stress-linked hormones. To do this, they implanted pellets that released glucocorticoids at a constant rate over 21 days under the skin of mice and compared them with normal mice who have normal daily fluctuations. The amount of brown and white fat in the mice with the glucocorticoid pellets doubled within 21 days, and insulin levels in their bodies skyrocketed even though the mice still ate the same healthy diet as the normal mice.

"If you stress the animals at the wrong time, it has a dramatic effect," Dr. Teruel said. "The mice aren't eating differently, but a big shift in metabolism causes weight gain."

Surprisingly, these metabolic disruptions seemed to have a "protective effect" by keeping blood sugar levels low and preventing fat from accumulating in the blood or liver. When they removed the pellets, the metabolic changes quickly reversed.

"It shows the animals can cope with chronic stress for a while," she said.

In the second study, Dr. Teruel and her colleagues attached a red fluorescent protein to protein that controls the expression of important circadian clock genes and a yellow fluorescent protein to peroxisome proliferator activated receptor gamma (PPARG), a protein that regulates fat cell production. They used these two fluorescent markers to monitor the daily fluctuations of PPARG and circadian gene expression in mouse fat cell precursors. During the rest period of the day, they found a circadian protein called CCAAT enhancer binding protein alpha (CEBPA) causes a rapid increase in the production of PPARG. Once PPARG levels reach a certain threshold, the precursor cells commit to becoming fat cells, a process that takes a few days to complete.

"The decision to become a fat cell happens rapidly over 4 hours. It is like a switch," she said. "It only happens at a certain time of day."

Dr. Teruel and her colleagues are now working to understand why disturbing the daily rhythms of glucocorticoids triggers temporary protective metabolic changes. They also want to learn whether prolonged stress or a high-fat diet makes these changes permanent. The results of these studies could help determine how long it is safe to treat individuals with glucocorticoid drugs for conditions like asthma.

The research might also lead to the development of drugs that help reset circadian rhythms in people with obesity as an alternative to more invasive treatments like bariatric surgery. Another possibility might be therapies targeting the 4-hour window when fat cell precursors commit to becoming fat cells to prevent excess fat accumulation.

Dr. Teruel and her colleagues also believe learning how to synchronize the body's cellular and master circadian clocks will be essential.

"Every cell in our body has an intrinsic cell clock, just like the fat cells, and we have a master clock in our brain, which controls hormone secretion," she said. "We are trying to understand how they work together and how we can coordinate them."

https://www.sciencedaily.com/releases/2022/08/220808211750.htm

Women urged to eat potassium-rich foods to improve their heart health

July 21, 2022

Science Daily/European Society of Cardiology

Women who eat bananas, avocados and salmon could reduce the negative effects of salt in the diet, according to a study published today in European Heart Journal, a journal of the European Society of Cardiology (ESC).1 The study found that potassium-rich diets were associated with lower blood pressure, particularly in women with high salt intake.

"It is well known that high salt consumption is associated with elevated blood pressure and a raised risk of heart attacks and strokes," said study author Professor Liffert Vogt of Amsterdam University Medical Centers, the Netherlands. "Health advice has focused on limiting salt intake but this is difficult to achieve when our diets include processed foods. Potassium helps the body excrete more sodium in the urine. In our study, dietary potassium was linked with the greatest health gains in women."

The study included 24,963 participants (11,267 men and 13,696 women) of the EPIC-Norfolk study, which recruited 40 to 79 year olds from general practices in Norfolk, UK, between 1993 and 1997. The average age was 59 years for men and 58 years for women. Participants completed a questionnaire on lifestyle habits, blood pressure was measured, and a urine sample was collected. Urinary sodium and potassium were used to estimate dietary intake. Participants were divided into tertiles according to sodium intake (low/medium/high) and potassium intake (low/medium/high).

The researchers analysed the association between potassium intake and blood pressure after adjusting for age, sex and sodium intake. Potassium consumption (in grams per day) was associated with blood pressure in women -- as intake went up, blood pressure went down. When the association was analysed according to sodium intake (low/medium/high), the relationship between potassium and blood pressure was only observed in women with high sodium intake, where every 1 gram increase in daily potassium was associated with a 2.4 mmHg lower systolic blood pressure. In men, there was no association between potassium and blood pressure.

During a median follow-up of 19.5 years, 13,596 (55%) participants were hospitalised or died due to cardiovascular disease. The researchers analysed the association between potassium intake and cardiovascular events after adjusting for age, sex, body mass index, sodium intake, use of lipid lowering drugs, smoking, alcohol intake, diabetes and prior heart attack or stroke. In the overall cohort, people in the highest tertile of potassium intake had a 13% lower risk of cardiovascular events compared to those in the lowest tertile. When men and women were analysed separately, the corresponding risk reductions were 7% and 11%, respectively. The amount of salt in the diet did not influence the relationship between potassium and cardiovascular events in men or women.

Professor Vogt said: "The results suggest that potassium helps preserve heart health, but that women benefit more than men. The relationship between potassium and cardiovascular events was the same regardless of salt intake, suggesting that potassium has other ways of protecting the heart on top of increasing sodium excretion."

The World Health Organization recommends that adults consume at least 3.5 grams of potassium and less than 2 grams of sodium (5 grams of salt) per day.2 High potassium foods include vegetables, fruit, nuts, beans, dairy products and fish. For example, a 115 gram banana has 375 mg of potassium, 154 grams of cooked salmon has 780 mg, a 136 gram potato has 500 mg, and 1 cup of milk has 375 mg.

Professor Vogt concluded: "Our findings indicate that a heart healthy diet goes beyond limiting salt to boosting potassium content. Food companies can help by swapping standard sodium-based salt for a potassium salt alternative in processed foods. On top of that, we should all prioritise fresh, unprocessed foods since they are both rich in potassium and low in salt."

https://www.sciencedaily.com/releases/2022/07/220721204852.htm

Could eating fruit more often keep depression at bay?

July 14, 2022

Science Daily/Aston University

A study surveyed 428 adults and looked at the relationship between their consumption of fruit, vegetables, sweet and savoury food snacks and their psychological health. The more often people ate fruit, the lower they scored for depression and the higher for mental wellbeing.

People who frequently eat fruit are more likely to report greater positive mental wellbeing and are less likely to report symptoms of depression than those who do not, according to new research from the College of Health and Life Sciences, Aston University.

The researchers' findings suggest that how often we eat fruit is more important to our psychological health than the total amount we consume during a typical week.

The team also found that people who eat savoury snacks such as crisps, which are low in nutrients, are more likely to report greater levels of anxiety.

Published in the British Journal of Nutrition, the study surveyed 428 adults from across the UK and looked at the relationship between their consumption of fruit, vegetables, sweet and savoury food snacks, and their psychological health.

After taking demographic and lifestyle factors such as age, general health and exercise into account, the research found that both nutrient-rich fruit and nutrient-poor savoury snacks appeared to be linked to psychological health. They also found that there was no direct association between eating vegetables and psychological health.

Based on the survey, the more often people ate fruit, the lower they scored for depression and the higher for mental wellbeing, independent of the overall quantity of fruit intake.

People who frequently snacked on nutrient-poor savoury foods (such as crisps) were more likely to experience 'everyday mental lapses' (known as subjective cognitive failures) and report lower mental wellbeing. A greater number of lapses, was associated with higher reported symptoms of anxiety, stress and depression, and lower mental wellbeing scores.

By contrast, there was no link between these everyday memory lapses and fruit and vegetable intake or sweet snacks, suggesting a unique relationship between these nutrient-poor savoury snacks, everyday mental lapses, and psychological health.

Examples of these frustrating little everyday mental lapses included forgetting where items had been placed, forgetting the purpose of going into certain rooms, and being unable to retrieve names of acquaintances whose name was on the 'tip of the tongue'.

Lead author, PhD student Nicola-Jayne Tuck commented: "Very little is known about how diet may affect mental health and wellbeing, and while we did not directly examine causality here, our findings could suggest that frequently snacking on nutrient-poor savoury foods may increase everyday mental lapses, which in turn reduces psychological health.

"Other studies have found an association between fruit and vegetables and mental health, but few have looked at fruit and vegetables separately -- and even fewer evaluate both frequency and quantity of intake.

"Both fruit and vegetables are rich in antioxidants, fibre and essential micronutrients which promote optimal brain function, but these nutrients can be lost during cooking. As we are more likely to eat fruit raw, this could potentially explain its stronger influence on our psychological health.

"It is possible that changing what we snack on could be a really simple and easy way to improve our mental wellbeing. Conversely, it is also possible that the forthcoming restriction of processed snack foods at checkouts, due to come in this October, could not only improve the country's physical health, but mental health too.

"Overall, it's definitely worth trying to get into the habit of reaching for the fruit bowl."

https://www.sciencedaily.com/releases/2022/07/220714145013.htm

A rhythmic small intestinal microbiome prevents obesity and type 2 diabetes

July 5, 2022

Science Daily/University of California - San Diego

An estimated 500 to 1,000 bacterial species reside in each person's gut, perhaps numbering 100,000 trillion microorganisms. In a new paper, published July 5, 2022 in Cell Reports, researchers at University of California San Diego School of Medicine used mouse models to explore how diet and feeding patterns affect these intestinal microbes -- and the health of the hosts, particularly with obesity and type 2 diabetes.

In both mice and men, the ileum is the final stretch of the small intestine, connecting to the cecum, the first part of the large intestine. In the ileum, nutrients are drawn out of liquefied food; in the cecum, which also marks the beginning of the colon, the process of extracting water begins.

Both processes are complex, dynamic and profoundly influenced by factors ranging from the types of foods consumed and when, to the microbial residents of the gut, whose presence and behaviors help dictate digestion, absorption of nutrients, vitamin synthesis and development of the immune system.

"It's important to realize that the gut microbiome is constantly changing, not only based on what we're eating, but also based on the time of day," said senior study author Amir Zarrinpar, MD, PhD, assistant professor of medicine at UC San Diego School of Medicine and a gastroenterologist at UC San Diego Health.

"Most researchers are getting snapshots of this constantly shifting environment, which makes it hard to understand what is going on in the gut. With this study, we are trying to get multiple snapshots throughout the day, almost like a movie, to better understand how food and the microbiome interact to affect weight gain and diabetes.

"And what we've learned is that cyclical changes in the gut microbiome are quite important for health since they help with the circadian clock, and with that the regulation and control of glucose, cholesterol and fatty acids -- and overall metabolic health."

In their latest work, Zarrinpar and colleagues further elucidate the impact and interplay of these factors, particularly in terms of the ileum and its unique functions related to digestion and absorption. Specifically, they looked at how diet-induced obesity (DIO) and time-restricted feeding (TRF) alter ileal microbiome composition and transcriptome (the protein-coding part of an organism's genome) in mouse models.

The researchers found that in mouse models, DIO and the absence of TRF (mice could eat as much as they wanted whenever they wanted) resulted in disruptions to gut microbiome rhythms and the signaling pathways that help modulate intestinal clocks. In other words, the mice became fat and unhealthy.

"It is interesting that restricting food access with TRF acts not only through restoration of patterns affected under the unhealthy state, but also through new pathways," said first author Ana Carolina Dantas Machado, PhD, a postdoctoral scholar in Zarrinpar's lab.

"These findings underscore the influence of diet and time restricted feeding patterns in maintaining a healthy gut microbiome, which in turn modulates circadian rhythms that govern metabolic health," said Zarrinpar. "It's a very complicated relationship between the microbiome and the host, with the former helping determine the latter's gastrointestinal functioning and health."

Their work, said the authors, can inform future studies, in particular investigations of how the gut works or how drugs act upon the gut function depending upon the state of the microbiome at a particular time or time of day.

https://www.sciencedaily.com/releases/2022/07/220705162154.htm

30-year study links childhood obesity and fitness to midlife cognition

June 16, 2022

Science Daily/Monash University

A new study of the impact of childhood fitness and obesity on cognition in middle age, followed over 1200 people who were children in 1985 for over 30 years, has found that better performance on physical tests is related to better cognition later in life and may protect against dementia in later years. Importantly these findings are not impacted by academic ability and socioeconomic status at childhood, or by smoking and alcohol consumption at midlife

The world's first study of the impact of childhood fitness and obesity on cognition in middle age, followed over 1200 people who were children in 1985 for over 30 years, has found that better performance on physical tests is related to better cognition later in life and may protect against dementia in later years.

Importantly these findings are not impacted by academic ability and socioeconomic status at childhood, or by smoking and alcohol consumption at midlife.

Led by Dr Jamie Tait and Associate Professor Michele Callisaya from the National Centre for Healthy Ageing, based at Peninsula Health and Monash University in Melbourne, along with investigators from the Childhood Determinants of Adult Health study from the Menzies Institute for Medical Research at the University of Tasmania, the landmark study is published today (TBC) in the Journal of Science and Medicine in Sport.

It is known that children who develop muscular strength, cardiorespiratory fitness and endurance due to sport and activity have better health outcomes later in life. Higher adult fitness is also associated with better cognition and reduced risk of dementia later in life.

Following over 1200 people from 1985 when they were between 7 and 15 years old all the way to 2017-19, this is the first significant study to look for links between objectively measured fitness and obesity in childhood with cognition in middle age, with the idea that early activity levels, fitness and metabolic health may protect against dementia in our older years.

In 1985, 1244 participants aged 7-15 years from the Australian Childhood Determinants of Adult Health study were assessed for fitness (cardiorespiratory, muscular power, muscular endurance) and anthropometry (waist-to-hip ratio).

These participants were followed up between 2017 and 2019 (aged 39-50, average age 44) in respect to their cognitive function using a series of computerised tests.

According to Associate Professor Callisaya this is the first study demonstrating a relationship between phenotypic profiles of objectively measured fitness and obesity measures at childhood, with midlife cognition.

The researchers found that children with the highest levels of cardio-respiratory and muscular fitness and lower average waist-to-hip ratio had higher midlife scores in tests of processing speed and attention, as well as in global cognitive function.

Because a decline in cognitive performance can begin as early as middle-age, and lower midlife cognition has been associated with a greater likelihood of developing mild cognitive impairment and dementia in older age, Associate Professor Callisaya states that it is important to identify factors in early life that may protect against cognitive decline during later life.

"Developing strategies that improve low fitness and decrease obesity levels in childhood are important because it could contribute to improvements in cognitive performance in midlife," she said.

"Importantly the study also indicates that protective strategies against future cognitive decline may need to start as far back as early childhood, so that the brain can develop sufficient reserve against developing conditions such as dementia in older life."

https://www.sciencedaily.com/releases/2022/06/220616121556.htm

Taste buds can adapt to low salt diet

May 23, 2022

Science Daily/European Society of Cardiology

A taste adaptation intervention lowers salt intake and increases enjoyment of a sodium restricted diet in patients with hypertension, according to a small study presented at ACNAP-EuroHeartCare Congress 2022, a scientific congress of the European Society of Cardiology (ESC).1

"One of the major barriers to sticking to a low salt diet is that people do not like the taste, but few studies have addressed this issue," said study author Professor Misook Chung of the University of Kentucky, Lexington, US. "Our pilot study in patients with high blood pressure shows that it is possible to change taste perception and learn to like food with less salt."

Hypertension affects more than one billion people worldwide and is the leading global cause of premature death.2 A healthy lifestyle, including salt restriction, is recommended to delay the need for blood pressure lowering drugs or complement their effects. However, the benefits of reduced sodium intake on blood pressure tend to diminish with time, partly due to poor adherence.

The researchers developed the Sodium Watchers Programme -- Hypertension (SWaP-HTN) for gradual taste adaptation to low salt food. This study examined its short-term effects on sodium intake, blood pressure, preference for salty food, and enjoyment of a sodium restricted diet. A total of 29 adults with hypertension were randomly assigned to the intervention or usual care in a 2:1 ratio. Participants in the usual care group received routine medical and nursing care for hypertension including advice to follow a sodium restricted diet and take prescribed medications.

The intervention group received 16 weeks of education and follow-up with a study nurse via video call on a tablet. Sessions were held weekly for six weeks, then every two weeks for 10 weeks. The programme was individualised to each patient's barriers and weekly goals and included salt added at the table, salt used during cooking, grocery shopping, and eating in restaurants. Participants received an electronic device that detects salt content to enable them to identify and avoid high salt food.

Professor Chung explained: "One of the first steps was for patients to realise how much salt they were eating. Using the electronic device they could test the salt content of restaurant meals and ask the chef to reduce or eliminate salt on their next visit. They also used it at home to lower the salt content in their own cooking. Some people automatically added salt at the table before tasting the food so we asked participants to count the number of 'shakes' and set goals for reducing it. Most participants removed the salt shaker from the table within three weeks."

At baseline and 16 weeks, all participants provided a 24-hour urine sample to assess sodium intake and had their blood pressure measured. In addition, preference for salty food and enjoyment of a salt restricted diet were assessed on a 10-point scale.

The average age of participants was 63 years and 55% were men. Three patients withdrew from the study and the final analysis included 17 and 9 participants in the intervention and usual care groups, respectively. The researchers compared changes from baseline to study completion between groups. The intervention led to a significant reduction in sodium intake and increased enjoyment of a salt restricted diet. There was a trend of decreasing mean systolic blood pressure in the intervention group, from 143.4 to 133.9 mmHg, but it did not reach statistical significance. The intervention did not change preference for salty food.

Professor Chung said: "In the intervention group, sodium intake dropped by 1,158 mg per day, which was a 30% reduction from baseline, while the control group increased daily intake by 500 mg. Enjoyment of a low salt diet increased in the intervention group, from 4.8 to 6.5 on a 10-point scale, although patients still preferred salty food. It is likely that the intervention did not translate to a statistically significant fall in blood pressure because of the small sample size."

She concluded: "Our study indicates that we can retrain our taste buds to enjoy low sodium food and gradually reduce the amount of salt we eat. The gradual taste adaptation programme has the potential to control blood pressure but needs to be tested in a larger trial with longer follow up."

https://www.sciencedaily.com/releases/2022/05/220523150647.htm

Diet plays key role in ADHD symptoms in children

Study finds more fruits and veggies means less inattention

May 19, 2022

Science Daily/Ohio State University

Here's a good reason for children with attention deficit hyperactivity disorder (ADHD) to eat their fruits and vegetables: It may help reduce inattention issues, a new study suggests.

As part of a larger study, researchers asked parents of 134 kids with ADHD symptoms to complete a detailed questionnaire about the typical foods the children ate, including portion sizes, over a 90-day period.

Another questionnaire asked parents to rate symptoms of inattention -- a hallmark of ADHD -- in their kids, such as having trouble staying focused, not following instructions, difficulty remembering things, and difficulty regulating emotions.

Results showed that kids who consumed more fruits and vegetables showed less severe symptoms of inattention, said Irene Hatsu, co-author of the study and associate professor of human nutrition at The Ohio State University.

"Eating a healthy diet, including fruits and vegetables, may be one way to reduce some of the symptoms of ADHD," Hatsu said.

The study was published online recently in the journal Nutritional Neuroscience.

The data for this research was collected as part of the Micronutrients for ADHD in Youth (MADDY) Study, which examined the efficacy of a 36-ingredient vitamin and mineral supplement to treat symptoms of ADHD and poor emotional control in the 134 kids aged 6 to 12.

The study that evaluated the effectiveness of the supplement showed that children who took the micronutrients were three times as likely to show significant improvement in their ADHD and emotional dysregulation symptoms than those who took a placebo. That study was published last year in the Journal of the American Academy of Child and Adolescent Psychiatry.

Another study involving the same children, published earlier this year in the journal Nutrients, showed that kids whose families had higher levels of food insecurity were more likely than others to show more severe symptoms of emotional dysregulation, such as chronic irritability, angry moods and outbursts of anger.

The three studies all paint a similar picture, Hatsu said: A healthy diet that provides all the nutrients that children require can help reduce the symptoms of ADHD in children.

"What clinicians usually do when kids with ADHD start having more severe symptoms is increase the dose of their treatment medication, if they are on one, or put them on medication," Hatsu said.

"Our studies suggest that it is worthwhile to check the children's access to food as well as the quality of their diet to see if it may be contributing to their symptom severity."

Children in the MADDY study, all of whom met the criteria for ADHD, were recruited from three sites: Columbus, Ohio; Portland, Oregon; and Lethbridge, Alberta, Canada. The study took place between 2018 and 2020. Participants were either not taking medication or stopped using it two weeks before the study began.

The studies on fruit and vegetable intake and the role of food insecurity were based on data collected when the children were first enrolled in the study, before they began taking the micronutrient supplement or placebo.

Why may diet be so important in ADHD?

Researchers believe that ADHD is related to low levels of some neurotransmitters in the brain -- and vitamins and minerals play a key role as cofactors in helping the body make those important neurochemicals and in overall brain function, Hatsu said.

Food insecurity may play an additional role.

"Everyone tends to get irritated when they're hungry and kids with ADHD are no exception. If they're not getting enough food, it could make their symptoms worse," she said.

Also, the stress of parents who are upset about not being able to provide enough food for their children can create family tension that could lead to more symptoms for children with ADHD.

The MADDY study is one of the first to look at the relationship between ADHD symptoms and diet quality among children in the United States and Canada, Hatsu said.

That's important because Western diets are more likely than many others, such as the Mediterranean diet, to fall short on fruit and vegetable intake, she said.

"We believe clinicians should assess the food security status of children with ADHD before creating or changing a treatment program," Hatsu said.

"Some symptoms might be more manageable by helping families become more food secure and able to provide a healthier diet."

https://www.sciencedaily.com/releases/2022/05/220519115333.htm

Cutting calories and eating at the right time of day leads to longer life in mice

May 5, 2022

Science Daily/Howard Hughes Medical Institute

In a study that followed hundreds of mice over their lifespans, calorie restriction combined with time-restricted eating boosted longevity.

One recipe for longevity is simple, if not easy to follow: eat less. Studies in a variety of animals have shown that restricting calories can lead to a longer, healthier life.

Now, new research suggests that the body's daily rhythms play a big part in this longevity effect. Eating only during their most active time of day substantially extended the lifespan of mice on a reduced-calorie diet, Howard Hughes Medical Institute Investigator Joseph Takahashi and colleagues report May 5, 2022, in the journal Science.

In his team's study of hundreds of mice over four years, a reduced-calorie diet alone extended the animals' lives by 10 percent. But feeding mice the diet only at nighttime, when mice are most active, extended life by 35 percent. That combo -- a reduced-calorie diet plus a nighttime eating schedule -- tacked on an extra nine months to the animals' typical two-year median lifespan. For people, an analogous plan would restrict eating to daytime hours.

The research helps disentangle the controversy around diet plans that emphasize eating only at certain times of day, says Takahashi, a molecular biologist at the University of Texas Southwestern Medical Center. Such plans may not speed weight loss in humans, as a recent study in the New England Journal of Medicine reported, but they could prompt health benefits that add up to a longer lifespan.

Takahashi's team's findings highlight the crucial role of metabolism in aging, says Sai Krupa Das, a nutrition scientist at the Jean Mayer USDA Human Nutrition Research Center on Aging who was not involved with the work. "This is a very promising and landmark study," she says.

Fountain of youth

Decades of research has found that calorie restriction extends the lifespan of animals ranging from worms and flies to mice, rats, and primates. Those experiments report weight loss, improved glucose regulation, lower blood pressure, and reduced inflammation.

Butit has been difficult to systematically study calorie restriction in people, who can't live in a laboratory and eat measured food portions for their entire lives, Das says. She was part of the research team that conducted the first controlled study of calorie restriction in humans, called the Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy, or CALERIE. In that study, even a modest reduction in calories "was remarkably beneficial" for reducing signs of aging, Das says.

Scientists are just beginning to understand how calorie restriction slows aging at the cellular and genetic level. As an animal ages, genes linked to inflammation tend to become more active, while genes that help regulate metabolism become less active. Takahashi's new study found that calorie restriction, especially when timed to the mice's active period at night, helped offset these genetic changes as mice aged.

Question of time

Recent years have seen the rise of many popular diet plans that focus on what's known as intermittent fasting, such as fasting on alternate days or eating only during a period of six to eight hours per day. To unravel the effects of calories, fasting, and daily, or circadian, rhythms on longevity, Takahashi's team undertook an extensive four-year experiment. The team housed hundreds of mice with automated feeders to control when and how much each mouse ate for its entire lifespan.

Some of the mice could eat as much as they wanted, while others had their calories restricted by 30 to 40 percent. And those on calorie-restricted diets ate on different schedules. Mice fed the low-calorie diet at night, over either a two-hour or 12-hour period, lived the longest, the team discovered.

The results suggest that time-restricted eating has positive effects on the body, even if it doesn't promote weight loss, as the New England Journal of Medicine study suggested. Takahashi points out that his study likewise found no differences in body weight among mice on different eating schedules -- "however, we found profound differences in lifespan," he says.

Rafael de Cabo, a gerontology researcher at the National Institute on Aging in Baltimore says that the Science paper "is a very elegant demonstration that even if you are restricting your calories but you are not [eating at the right times], you do not get the full benefits of caloric restriction."

Takahashi hopes that learning how calorie restriction affects the body's internal clocks as we age will help scientists find new ways to extend the healthy lifespan of humans. That could come through calorie-restricted diets, or through drugs that mimic those diets' effects.

In the meantime, Takahashi is taking a lesson from his mice - he restricts his own eating to a 12-hour period. But, he says, "if we find a drug that can boost your clock, we can then test that in the laboratory and see if that extends lifespan."

https://www.sciencedaily.com/releases/2022/05/220505143753.htm

A better diet helps beat depression in young men

May 9, 2022

Science Daily/University of Technology Sydney

Young men with a poor diet saw a significant improvement in their symptoms of depression when they switched to a healthy Mediterranean diet, a new study shows.

Depression is a common mental health condition that affects approximately 1 million Australians each year. It is a significant risk factor for suicide, the leading cause of death in young adults.

The 12-week randomised control trial, conducted by researchers from the University of Technology Sydney, was recently published in the peer-reviewed American Journal of Clinical Nutrition.

Lead researcher Jessica Bayes, a PhD candidate in the UTS Faculty of Health, said the study was the first randomised clinical trial to assess the impact of a Mediterranean diet on the symptoms of depression in young men (aged 18-25).

"We were surprised by how willing the young men were to take on a new diet," Bayes said. "Those assigned to the Mediterranean diet were able to significantly change their original diets, under the guidance of a nutritionist, over a short time frame."

"It suggests that medical doctors and psychologists should consider referring depressed young men to a nutritionist or dietitian as an important component of treating clinical depression," she said.

The study contributes to the emerging field of nutritional psychiatry, which aims to explore the effect that specific nutrients, foods and dietary patterns can have on mental health. The diet used in the study was rich in colourful vegetables, legumes and wholegrains, oily fish, olive oil and raw, unsalted nuts.

"The primary focus was on increasing diet quality with fresh wholefoods while reducing the intake of 'fast' foods, sugar and processed red meat," Bayes said.

"There are lots of reasons why scientifically we think food affects mood. For example, around 90 per cent of serotonin, a chemical that helps us feel happy, is made in our gut by our gut microbes. There is emerging evidence that these microbes can communicate to the brain via the vagus nerve, in what is called the gut-brain axis.

"To have beneficial microbes, we need to feed them fibre, which is found in legumes, fruits and vegetables," she said.

Roughly 30 per cent of depressed patients fail to adequately respond to standard treatments for major depressive disorder such as cognitive behaviour therapy and anti-depressant medications.

"Nearly all our participants stayed with the program, and many were keen to continue the diet once the study ended, which shows how effective, tolerable and worthwhile they found the intervention."

https://www.sciencedaily.com/releases/2022/05/220509112049.htm

Study finds children with vegetarian diet have similar growth and nutrition compared to children who eat meat

Children with a vegetarian diet also had higher odds of underweight weight status

May 2, 2022

Science Daily/St. Michael's Hospital

A study of nearly 9,000 children found those who eat a vegetarian diet had similar measures of growth and nutrition compared to children who eat meat. The study, published in Pediatrics and led by researchers at St. Michael’s Hospital of Unity Health Toronto, also found that children with a vegetarian diet had higher odds of underweight weight status, emphasizing the need for special care when planning the diets of vegetarian kids.

The findings come as a shift to consuming a plant-based diet grows in Canada. In 2019, updates to Canada’s Food Guide urged Canadians to embrace plant-based proteins, such as beans and tofu, instead of meat.

“Over the last 20 years we have seen growing popularity of plant-based diets and a changing food environment with more access to plant-based alternatives, however we have not seen research into the nutritional outcomes of children following vegetarian diets in Canada,” said Dr. Jonathon Maguire, lead author of the study and a pediatrician at St. Michael’s Hospital of Unity Health Toronto.

“This study demonstrates that Canadian children following vegetarian diets had similar growth and biochemical measures of nutrition compared to children consuming non-vegetarian diets. Vegetarian diet was associated with higher odds of underweight weight status, underscoring the need for careful dietary planning for children with underweight when considering vegetarian diets.”

Researchers evaluated 8,907 children age six months to eight years. The children were all participants of the TARGet Kids! cohort study and data was collected between 2008 and 2019. Participants were categorized by vegetarian status – defined as a dietary pattern that excludes meat – or non-vegetarian status.

Researchers found children who had a vegetarian diet had similar mean body mass index (BMI), height, iron, vitamin D, and cholesterol levels compared to those who consumed meat. The findings showed evidence that children with a vegetarian diet had almost two-fold higher odds of having underweight, which is defined as below the third percentile for BMI. There was no evidence of an association with overweight or obesity.

Underweight is an indicator of undernutrition, and may be a sign that the quality of the child’s diet is not meeting the child’s nutritional needs to support normal growth. For children who eat a vegetarian diet, the researchers emphasized access to healthcare providers who can provide growth monitoring, education and guidance to support their growth and nutrition.

International guidelines about vegetarian diet in infancy and childhood have differing recommendations, and past studies that have evaluated the relationship between vegetarian diet and childhood growth and nutritional status have had conflicting findings.

“Plant-based dietary patterns are recognized as a healthy eating pattern due to increased intake of fruits, vegetables, fiber, whole grains, and reduced saturated fat; however, few studies have evaluated the impact of vegetarian diets on childhood growth and nutritional status. Vegetarian diets appear to be appropriate for most children,” said Dr. Maguire, who is also a scientist at MAP Centre for Urban Health Solutions at St. Michael’s Hospital.

A limitation of the study is that researchers did not assess the quality of the vegetarian diets. The researchers note that vegetarian diets come in many forms and the quality of the individual diet may be quite important to growth and nutritional outcomes. The authors say further research is needed to examine the quality of vegetarian diets in childhood, as well as growth and nutrition outcomes among children following a vegan diet, which excludes meat and animal derived products such as dairy, egg, and honey.

https://www.sciencedaily.com/releases/2022/05/220502094813.htm

Intense exercise while dieting may reduce cravings for fatty food

April 21, 2022

Science Daily/Washington State University

In a study that offers hope for human dieters, rats on a 30-day diet who exercised intensely resisted cues for favored, high-fat food pellets.

The experiment was designed to test resistance to the phenomenon known as "incubation of craving," meaning the longer a desired substance is denied, the harder it is to ignore signals for it. The findings suggest that exercise modulated how hard the rats were willing to work for cues associated with the pellets, reflecting how much they craved them.

While more research needs to be done, the study may indicate that exercise can shore up restraint when it comes to certain foods, said Travis Brown, a Washington State University physiology and neuroscience researcher.

"A really important part of maintaining a diet is to have some brain power -- the ability to say 'no, I may be craving that, but I'm going to abstain,'" said Brown, corresponding author on the study published in the journal Obesity. "Exercise could not only be beneficial physically for weight loss but also mentally to gain control over cravings for unhealthy foods."

In the experiment, Brown and colleagues from WSU and University of Wyoming put 28 rats through a training with a lever that when pressed, turned on a light and made a tone before dispensing a high-fat pellet. After the training period, they tested to see how many times the rats would press the lever just to get the light and tone cue.

The researchers then split the rats into two groups: one underwent a regime of high-intensity treadmill running; the other had no additional exercise outside of their regular activity. Both sets of rats were denied access to the high-fat pellets for 30 days. At the end of that period, the researchers gave the rats access to the levers that once dispensed the pellets again, but this time when the levers were pressed, they only gave the light and tone cue. The animals that did not get exercise pressed the levers significantly more than rats that had exercised, indicating that exercise lessened the craving for the pellets.

In future studies, the research team plans to investigate the effect of different levels of exercise on this type of craving as well as how exactly exercise works in the brain to curb the desire for unhealthy foods.

While this study is novel, Brown said it builds on the work of Jeff Grimm at Western Washington University who led the team that first defined the term "incubation of craving" and has studied other ways to subvert it. Brown also credited Marilyn Carroll-Santi's research at University of Minnesota showing that exercise can blunt cravings for cocaine.

It is still an unsettled research question as to whether food can be addictive in the same way as drugs. Not all foods appear to have an addictive effect; as Brown pointed out, "no one binge eats broccoli." However, people do seem to respond to cues, such as fast-food ads, encouraging them to eat foods high in fat or sugar, and those cues may be harder to resist the longer they diet.

The ability to disregard these signals may be yet another way exercise improves health, Brown said.

"Exercise is beneficial from a number of perspectives: it helps with cardiac disease, obesity and diabetes; it might also help with the ability to avoid some of these maladaptive foods," he said. "We're always looking for this magic pill in some ways, and exercise is right in front of us with all these benefits."

https://www.sciencedaily.com/releases/2022/04/220421094049.htm