Sugar overload may be a recipe for long-term problems

A new study on the impact of sugar supports World Health Organization recommendations

June 8, 2021

Science Daily/Queensland University of Technology

Children who consume too much sugar could be at greater risk of becoming obese, hyperactive, and cognitively impaired, as adults, according to the results of a new study of mice led by QUT and published by Frontiers in Neuroscience.

The study resulted in a reduced risk of sugar-induced weight gain and other health problems when the mice were given a much smaller daily dose of sucrose, supporting World Health Organisation calls for a reduction in sugar intake by humans.

One of the lead authors, QUT neuroscientist Professor Selena Bartlett, says many children, adolescents, and adults in more than 60 countries, including Australia, have a diet consisting of more than four times the sugar (100g) recommended by the World Health Organisation (25g per person per day).

"More work needs to be done in the investigation of the long-term effects of sugar on adolescents and adults but our results with the mouse model are very promising," said Professor Bartlett.

"Recent evidence shows obesity and impulsive behaviours caused by poor dietary habits leads to further overconsumption of processed food and beverages but the long-term effects on cognitive processes and hyperactivity from sugar overconsumption, beginning at adolescence, are not known," said Professor Bartlett.

"Our study found long-term sugar consumption (a 12-week period with the mice which started the trial at five weeks of age) at a level that significantly boosts weight gain, elicits an abnormal and excessive stimulation of the nervous system in response to novelty. It also alters both episodic and spatial memory. These results are like those reported in attention deficit and hyperactivity disorders.

"Human trials would need to be done but it suggests a link to the long-term overconsumption of sugar, beginning at a young age, which occurs more commonly in the Western Diet and an increased risk of developing persistent hyperactivity and neurocognitive deficits in adulthood."

Professor Bartlett said while the concept of 'sugar addiction' and the classification of sugar as a substance of abuse were still being debated, there is increasing evidence of overlap in the brain circuitry and molecular signalling pathways involved in sugar consumption and drug abuse.

"People consume sugar and food to regulate energy balance, but also for pleasure and comfort. This hedonistic desire for palatable food is reward-driven and overeating can impact upon and even override our ability to regulate," Professor Bartlett said.

"It is increasingly considered that unrestricted consumption of high-sugar food and beverages within the Western Diet might be linked to the increased obesity epidemic. A strong association between attention-deficits/hyperactivity disorders and being overweight or obese have also been revealed.

"Taken together, these data suggest that sugar-induced obesity may participate to the developing pathogenesis of ADHD-like symptoms in western countries. In children, high sugar consumption correlates with hyperactivity and in adults, with inattention and impulsivity.

"What has been unclear though, is whether chronic overconsumption of sucrose -- starting from childhood -- would have the same negative impact on our nervous system, emotions or cognition throughout adulthood as other addictive drugs.

"This study on mice goes a long way to resolving that question. Our results show for the first time that long-term consumption of sucrose leads to significant weight gain and produces persistent hyperactivity and learning impairments."

Co-lead author Dr Arnauld Belmer added that while the overall sugar consumption has dropped since the mid-1990s, obesity rates have climbed.

"This rise in obesity rates could result from a delayed effect of excess sugar, suggesting that adult obesity may be driven by high sugar intake over a life span," Dr Belmer said.

"Interestingly, our investigation with the mice found reducing the daily sucrose intake four-fold did prevent sugar-induced increase in weight gain, supporting the WHO's recommendation to restrict sugar intake by this amount would be effective. It could also limit the other negative consequences including hyperactivity and cognitive impairment."

https://www.sciencedaily.com/releases/2021/06/210608092239.htm

Gut to brain: Nerve cells detect what we eat

June 2, 2021

Science Daily/Max-Planck-Gesellschaft

The gut and the brain communicate with each other in order to adapt satiety and blood sugar levels during food consumption. The vagus nerve is an important communicator between these two organs. Researchers from the Max Planck Institute for Metabolism Research in Cologne, the Cluster of Excellence for Ageing Research CECAD at the University of Cologne and the University Hospital Cologne now took a closer look at the functions of the different nerve cells in the control centre of the vagus nerve, and discovered something very surprising: although the nerve cells are located in the same control center, they innervate different regions of the gut and also differentially control satiety and blood sugar levels. This discovery could play an important role in the development of future therapeutic strategies against obesity and diabetes.

When we consume food, information about the ingested food is transmitted from the gastrointestinal tract to the brain in order to adapt feelings of hunger and satiety. Based on this information, the brain decides, for example, whether we continue or stop eating. In addition, our blood sugar level are adapted by the brain. The vagus nerve, which extends from the brain all the way down to the gastrointestinal tract, plays an essential role in this communication. In the control center of the vagus nerve, the so-called nodose ganglion, various nerve cells are situated, some of which innervate the stomach while others innervate the intestine. Some of these nerve cells detect mechanical stimuli in the different organs, such as stomach stretch during feeding, while others detect chemical signals, such as nutrients from the food that we consume. But what roles these different nerve cells play in transmitting information from the gut to the brain, and how their activity contributes to adaptations of feeding behavior and blood sugar levels had remained largely unclear.

"To investigate the function of the nerve cells in the nodose ganglion, we developed a genetic approach that enables us to visualize the different nerve cells and manipulate their activity in mice. This allowed us to analyze which nerve cells innervate which organ, pointing to what kind of signals they detect in the gut," says study leader Henning Fenselau. "It also allowed us to specifically switch on and off the different types of nerve cells to analyze their precise function."

Different food activates different nerve cells

In their studies, the researchers focused primarily on two types of nerve cells of the nodose ganglion, which is just one millimeter in size. "One of these cell types detects stomach stretch, and activation of these nerve cells causes mice to eat significantly less," Fenselau explains. "We identified that activity of these nerve cells is key for transmitting appetite-inhibiting signals to the brain and also decreasing blood sugar levels." The second group of nerve cells primarily innervates the intestine. "This group of nerve cells senses chemical signals from our food. However, their activity is not necessary for feeding regulation. Instead, activation of these cells increases our blood sugar level," says Fenselau. Thus, these two types of nerve cells in the control center of the vagus nerve fulfil very different functions.

"The reaction of our brain during food consumption is probably an interplay of these two nerve cell types," Fenselau explains. "Food with a lot of volume stretches our stomach, and activates the nerve cell types innervating this organ. At a certain point, their activation promotes satiety and hence halts further food intake, and at the same time coordinates the adaptations of blood sugar levels. Food with a high nutrient density tends to activate the nerve cells in the intestine. Their activation increases blood glucose levels by coordinating the release of the body's own glucose, but they do not halt further food intake." The discovery of the different functions of these two types of nerve cells could play a crucial role in developing new therapeutic strategies against obesity and diabetes.

https://www.sciencedaily.com/releases/2021/06/210602130330.htm

People who eat a healthy diet including whole fruits may be less likely to develop diabetes

Research links fruit but not fruit juice to lower type 2 diabetes risk

June 2, 2021

Science Daily/The Endocrine Society

A new study finds people who consume two servings of fruit per day have 36 percent lower odds of developing type 2 diabetes than those who consume less than half a serving. The research was published in the Endocrine Society's Journal of Clinical Endocrinology & Metabolism.

Diabetes is a disease where people have too much sugar in their bloodstream, and it is a huge public health burden. Approximately 463 million adults worldwide were living with diabetes in 2019, and by 2045 this number is expected to rise to 700 million. An estimated 374 million people are at increased risk of developing type 2 diabetes, the most common form of the disease. A healthy diet and lifestyle can play a major role in lowering a person's diabetes risk.

"We found people who consumed around 2 servings of fruit per day had a 36 percent lower risk of developing type 2 diabetes over the next five years than those who consumed less than half a serving of fruit per day," said study author Nicola Bondonno, Ph.D., of Edith Cowan University's Institute for Nutrition Research in Perth, Australia. "We did not see the same patterns for fruit juice. These findings indicate that a healthy diet and lifestyle which includes the consumption of whole fruits is a great strategy to lower your diabetes risk."

The researchers studied data from 7,675 participants from the Baker Heart and Diabetes Institute's Australian Diabetes, Obesity and Lifestyle Study who provided information on their fruit and fruit juice intake through a food frequency questionnaire. They found participants who ate more whole fruits had 36 percent lower odds of having diabetes at five years. The researchers found an association between fruit intake and markers of insulin sensitivity, meaning that people who consumed more fruit had to produce less insulin to lower their blood glucose levels.

"This is important because high levels of circulating insulin (hyperinsulinemia) can damage blood vessels and are related not only to diabetes, but also to high blood pressure, obesity and heart disease," Bondonno said.

https://www.sciencedaily.com/releases/2021/06/210602091404.htm

Western diet may increase risk of gut inflammation, infection

Diet rich in sugar, fat damages immune cells in digestive tracts of mice

May 18, 2021

Science Daily/Washington University School of Medicine

Eating a Western diet impairs the immune system in the gut in ways that could increase risk of infection and inflammatory bowel disease, according to a study from researchers at Washington University School of Medicine in St. Louis and Cleveland Clinic.

The study, in mice and people, showed that a diet high in sugar and fat causes damage to Paneth cells, immune cells in the gut that help keep inflammation in check. When Paneth cells aren't functioning properly, the gut immune system is excessively prone to inflammation, putting people at risk of inflammatory bowel disease and undermining effective control of disease-causing microbes. The findings, published May 18 in Cell Host & Microbe, open up new approaches to regulating gut immunity by restoring normal Paneth cell function.

"Inflammatory bowel disease has historically been a problem primarily in Western countries such as the U.S., but it's becoming more common globally as more and more people adopt Western lifestyles," said lead author Ta-Chiang Liu, MD, PhD, an associate professor of pathology & immunology at Washington University. "Our research showed that long-term consumption of a Western-style diet high in fat and sugar impairs the function of immune cells in the gut in ways that could promote inflammatory bowel disease or increase the risk of intestinal infections."

Paneth cell impairment is a key feature of inflammatory bowel disease. For example, people with Crohn's disease, a kind of inflammatory bowel disease characterized by abdominal pain, diarrhea, anemia and fatigue, often have Paneth cells that have stopped working.

Liu and senior author Thaddeus Stappenbeck, MD, PhD, chair of the Department of Inflammation and Immunity at Cleveland Clinic, set out to find the cause of Paneth cell dysfunction in people. They analyzed a database containing demographic and clinical data on 400 people, including an assessment of each person's Paneth cells. The researchers found that high body mass index (BMI) was associated with Paneth cells that looked abnormal and unhealthy under a microscope. The higher a person's BMI, the worse his or her Paneth cells looked. The association held for healthy adults and people with Crohn's disease.

To better understand this connection, the researchers studied two strains of mice that are genetically predisposed to obesity. Such mice chronically overeat because they carry mutations that prevent them from feeling full even when fed a regular diet. To the researchers' surprise, the obese mice had Paneth cells that looked normal.

In people, obesity is frequently the result of eating a diet rich in fat and sugar. So the scientists fed normal mice a diet in which 40% of the calories came from fat or sugar, similar to the typical Western diet. After two months on this chow, the mice had become obese and their Paneth cells looked decidedly abnormal.

"Obesity wasn't the problem per se," Liu said. "Eating too much of a healthy diet didn't affect the Paneth cells. It was the high-fat, high-sugar diet that was the problem."

The Paneth cells returned to normal when the mice were put back on a healthy mouse diet for four weeks. Whether people who habitually eat a Western diet can improve their gut immunity by changing their diet remains to be seen, Liu said.

"This was a short-term experiment, just eight weeks," Liu said. "In people, obesity doesn't occur overnight or even in eight weeks. People have a suboptimal lifestyle for 20, 30 years before they become obese. It's possible that if you have Western diet for so long, you cross a point of no return and your Paneth cells don't recover even if you change your diet. We'd need to do more research before we can say whether this process is reversible in people."

Further experiments showed that a molecule known as deoxycholic acid, a secondary bile acid formed as a byproduct of the metabolism of gut bacteria, forms the link between a Western diet and Paneth cell dysfunction. The bile acid increases the activity of two immune molecules -- farnesoid X receptor and type 1 interferon -- that inhibit Paneth cell function.

Liu and colleagues now are investigating whether fat or sugar plays the primary role in impairing Paneth cells. They also have begun studying ways to restore normal Paneth cell function and improve gut immunity by targeting the bile acid or the two immune molecules.

https://www.sciencedaily.com/releases/2021/05/210518114235.htm

Overweight or obesity worsens liver-damaging effects of alcohol

June 1, 2021

Science Daily/University of Sydney

Led by the University of Sydney's Charles Perkins Centre, the study looked at medical data from nearly half a million people and found having overweight or obesity considerably amplified the harmful effects of alcohol on liver disease and mortality.

"People in the overweight or obese range who drank were found to be at greater risk of liver diseases compared with participants within a healthy weight range who consumed alcohol at the same level," said senior author and research program director Professor Emmanuel Stamatakis from the Charles Perkins Centre and the Faculty of Medicine and Health.

"Even for people who drank within alcohol guidelines, participants classified as obese were at over 50 percent greater risk of liver disease."

The researchers drew upon data from the UK Biobank -- a large-scale biomedical cohort study containing in-depth biological, behavioural, and health information from participants in the United Kingdom (UK).

According to the researchers, this is one of the first and largest studies looking at increased adiposity (overweight or obesity) and level of alcohol consumption together, in relation to future liver disease.

Information was examined from 465,437 people aged 40 to 69 years, with medical and health details collected over an average of 10.5 years.

The findings were published in the European Journal of Clinical Nutrition.

Lead author Dr Elif Inan-Eroglu, a postdoctoral research fellow with the Charles Perkins Centre, said the results suggest people carrying excess weight may need to be more aware of risks around alcohol consumption.

"With the most recent data suggesting two in three people -- or 67 percent of the Australian population are in the overweight or obesity range, this is obviously a very topical issue."

Key findings 

The researchers reviewed data on participants classified as overweight/obese based on their body mass index (BMI) and waist circumference, self-reported alcohol consumption according to UK alcohol guidelines, and liver disease incidence and liver disease as cause of death.

BMI is based on both weight and height. A BMI of over 25 denotes overweight, and over 30 denotes obesity. For waist circumference, researchers used the World Health Organization (WHO) classification: normal (<80 cm for women, <94 cm for men), overweight (>80 cm for women, >94 cm for men), and obese (>88 cm for women, >102 cm for men).

The level of risk was given a number called a 'hazard ratio'. The higher the number than 1, the higher the risk.

- People who drank above UK alcohol guidelines had, compared to within guideline drinkers: 

o A nearly 600 percent higher risk of being diagnosed with alcoholic fatty liver disease (5.83 hazard ratio). 

o A nearly 700 percent higher risk of death caused by alcoholic fatty liver disease (6.94 hazard ratio).

- People with overweight or obesity who drank within or above alcohol guidelines had over 50 percent greater risk of developing liver disease compared to normal weight participants who consumed alcohol at the same level.

https://www.sciencedaily.com/releases/2021/06/210601100701.htm

A complex link between body mass index and Alzheimer's

Study finds combined genetic risk, lower BMI predict disease progression

May 19, 2021

Science Daily/Ohio State University

Though obesity in midlife is linked to an increased risk for Alzheimer's disease, new research suggests that a high body mass index later in life doesn't necessarily translate to greater chances of developing the brain disease.

In the study, researchers compared data from two groups of people who had been diagnosed with mild cognitive impairment -- half whose disease progressed to Alzheimer's in 24 months and half whose condition did not worsen.

The researchers zeroed in on two risk factors: body mass index (BMI) and a cluster of genetic variants associated with higher risk for Alzheimer's disease.

Their analysis showed that a higher genetic risk combined with a lower BMI was associated with a higher likelihood for progression to Alzheimer's, and that the association was strongest in men.

The finding does not suggest people should consider gaining weight in their later years as a preventive effort -- instead, researchers speculate that lower BMI in these patients was likely a consequence of neurodegeneration, the progressive damage to the brain that is a hallmark of Alzheimer's. Brain regions affected by Alzheimer's are also involved in controlling eating behaviors and weight regulation.

"We don't want people to think they can eat everything they want because of this lower BMI association," said senior study author Jasmeet Hayes, assistant professor of psychology at The Ohio State University.

"We know that maintaining a healthy weight and having a healthy diet are extremely important to keeping inflammation and oxidative stress down -- that's a risk factor that is modifiable, and it's something you can do to help improve your life and prevent neurodegenerative processes as much as possible," she said. "If you start to notice rapid weight loss in an older individual, that could actually be a reflection of a potential neurodegenerative disease process."

The study was published online recently in the Journals of Gerontology: Series A.

Previous research has found a link between obesity and negative cognitive outcomes, but in older adults closer to the age at which Alzheimer's disease is diagnosed, the results have been mixed, Hayes said. And though a variant to the gene known as APOE4 is the strongest single genetic risk factor for Alzheimer's, it explains only about 10 to 15% of overall risk, she said.

Hayes has focused her research program on looking at multiple risk factors at the same time to see how they might interact to influence risk -- and to identify health behaviors that may help reduce the risk.

"We're trying to add more and more factors. That is my goal, to one day build a more precise and better model of the different combinations of risk factors," said Hayes, also an investigator in Ohio State's Chronic Brain Injury Initiative. "Genetic risk is important, but it really explains only a small part of Alzheimer's disease, so we're really interested in looking at other factors that we can control."

For this study, the research team obtained data from the Alzheimer's Disease Neuroimaging Initiative, compiling a sample of 104 people for whom BMI and polygenic risk scores were available. Fifty-two individuals whose mild cognitive impairment (MCI) had progressed to Alzheimer's in 24 months were matched against demographically similar people whose MCI diagnosis did not change over two years. Their average age was 73.

Statistical analysis showed that individuals with mild cognitive impairment who had both a lower BMI and higher genetic risk for Alzheimer's were more likely to progress to Alzheimer's disease within 24 months compared to people with a higher BMI.

"We think there's interaction between the genetics and lower BMI, and having both of these risk factors causes more degeneration in certain brain regions to increase the likelihood of developing Alzheimer's disease," said Jena Moody, a graduate student in psychology at Ohio State and first author of the paper.

The effect of the BMI-genetic risk interaction was significant even after taking into account the presence of beta-amyloid and tau proteins in the patients' cerebrospinal fluid -- the core biomarkers of Alzheimer's disease.

The relationship between low BMI and high genetic risk and progression to Alzheimer's was stronger in males than in females, but a larger sample size and additional biological data would be needed to expand on that finding, the researchers said.

Because brain changes can begin long before cognitive symptoms surface, a better understanding of the multiple risk factors for Alzheimer's could open the door to better prevention options, Moody said.

"If you can identify people at higher risk before symptoms manifest, you could implement interventions and prevention techniques to either slow or prevent that progression from happening altogether," she said.

To date, scientists have suggested preventive steps include maintaining a healthy weight and diet and participating in activities that reduce inflammation and promote neurofunctioning, such as exercise and mentally stimulating activities.

"We're finding again and again how important inflammation is in the process," Hayes said. "Especially in midlife, trying to keep that inflammation down is such an important aspect of maintaining a healthy lifestyle and preventing accelerated aging."

https://www.sciencedaily.com/releases/2021/05/210519120835.htm

Eating more fruit and vegetables linked to less stress

May 14, 2021

Science Daily/Edith Cowan University

Eating a diet rich in fruit and vegetables is associated with less stress, according to new research from Edith Cowan University (ECU).

The study examined the link between fruit and vegetable intake and stress levels of more than 8,600 Australians aged between 25 and 91 participating in the Australian Diabetes, Obesity and Lifestyle (AusDiab) Study from Baker Heart and Diabetes Institute.

The findings revealed people who ate at least 470 grams of fruit and vegetables daily had 10 per cent lower stress levels than those who consumed less than 230 grams. The World Health Organization (WHO) recommends eating at least 400 grams of fruit and vegetables per day.

Lead researcher, PhD candidate Simone Radavelli-Bagatini from ECU's Institute for Nutrition Research, said the study strengthens the link between diets rich in fruit and vegetables and mental wellbeing.

"We found that people who have higher fruit and veggie intakes are less stressed than those with lower intakes, which suggests diet plays a key role in mental wellbeing," said Ms Radavelli-Bagatini.

A growing issue

Mental health conditions are an increasing problem in Australia and around the world. Around one in two Australians will experience a mental health issue in their lifetime. Globally, approximately 1 in 10 people live with a mental health disorder.

According to Ms Radavelli-Bagatini, some stress is considered normal, but long-term exposure can significantly impact mental health.

"Long-term and unmanaged stress can lead to a range of health problems including heart disease, diabetes, depression and anxiety so we need to find ways to prevent and possibly alleviate mental health problems in the future," said Ms Radavelli-Bagatini.

The benefits of a healthy diet are well known, but only 1 in 2 Australians eat the recommended two serves of fruit per day and fewer than 1 in 10 eat the recommended five serves of vegetables each day.

"Previous studies have shown the link between fruit and vegetable consumption and stress in younger adults, but this is the first time we're seeing similar results across adults of all ages," said Ms Radavelli-Bagatini.

"The study's findings emphasise that it's important for people to have a diet rich in fruit and vegetables to potentially minimise stress."

Food and mood

While the mechanisms behind how fruit and vegetable consumption influences stress are still unclear, Ms Radavelli-Bagatini said key nutrients could be a factor.

"Vegetables and fruits contain important nutrients such as vitamins, minerals, flavonoids and carotenoids that can reduce inflammation and oxidative stress, and therefore improve mental wellbeing," she said.

"Inflammation and oxidative stress in the body are recognised factors that can lead to increased stress, anxiety and lower mood."

"These findings encourage more research into diet and specifically what fruits and vegetables provide the most benefits for mental health."

The research is part of ECU's recently launched Institute for Nutrition Research, which aims to investigate how nutrition can help prevent and treat chronic health conditions.

'Fruit and vegetable intake is inversely associated with perceived stress across the adult lifespan' was published in Clinical Nutrition.

https://www.sciencedaily.com/releases/2021/05/210513100030.htm

Vegetarians have healthier levels of disease markers than meat-eaters

May 9, 2021

Science Daily/European Association for the Study of Obesity

Vegetarians appear to have a healthier biomarker profile than meat-eaters, and this applies to adults of any age and weight, and is also unaffected by smoking and alcohol consumption, according to a new study in over 166,000 UK adults, being presented at this week's European Congress on Obesity (ECO), held online this year.

Biomarkers can have bad and good health effects, promoting or preventing cancer, cardiovascular and age-related diseases, and other chronic conditions, and have been widely used to assess the effect of diets on health. However, evidence of the metabolic benefits associated with being vegetarian is unclear.

To understand whether dietary choice can make a difference to the levels of disease markers in blood and urine, researchers from the University of Glasgow did a cross-sectional study analysing data from 177,723 healthy participants (aged 37-73 years) in the UK Biobank study, who reported no major changes in diet over the last five years.

Participants were categorised as either vegetarian (do not eat red meat, poultry or fish; 4,111 participants) or meat-eaters (166,516 participants) according to their self-reported diet. The researchers examined the association with 19 blood and urine biomarkers related to diabetes, cardiovascular diseases, cancer, liver, bone and joint health, and kidney function.

Even after accounting for potentially influential factors including age, sex, education, ethnicity, obesity, smoking, and alcohol intake, the analysis found that compared to meat-eaters, vegetarians had significantly lower levels of 13 biomarkers, including: total cholesterol; low-density lipoprotein (LDL) cholesterol -- the so-called 'bad cholesterol; apolipoprotein A (linked to cardiovascular disease), apolipoprotein B (linked to cardiovascular disease); gamma-glutamyl transferase (GGT) and alanine aminotransferase (AST) -- liver function markers indicating inflammation or damage to cells; insulin-like growth factor (IGF-1; a hormone that encourages the growth and proliferation of cancer cells); urate; total protein; and creatinine (marker of worsening kidney function).

However, vegetarians also had lower levels of beneficial biomarkers including high-density lipoprotein 'good' (HDL) cholesterol, and vitamin D and calcium (linked to bone and joint health). In addition, they had significantly higher level of fats (triglycerides) in the blood and cystatin-C (suggesting a poorer kidney condition).

No link was found for blood sugar levels (HbA1c), systolic blood pressure, aspartate aminotransferase (AST; a marker of damage to liver cells) or C-reactive protein (CRP; inflammatory marker).

"Our findings offer real food for thought," says Dr Carlos Celis-Morales from the University of Glasgow, UK, who led the research. "As well as not eating red and processed meat which have been linked to heart diseases and some cancers, people who follow a vegetarian diet tend to consume more vegetables, fruits, and nuts which contain more nutrients, fibre, and other potentially beneficial compounds. These nutritional differences may help explain why vegetarians appear to have lower levels of disease biomarkers that can lead to cell damage and chronic disease."

The authors point out that although their study was large, it was observational, so no conclusions can be drawn about direct cause and effect. They also note several limitations including that they only tested biomarker samples once for each participant, and it is possible that biomarkers might fluctuate depending on factors unrelated to diet, such as existing diseases and unmeasured lifestyle factors. They also note that were reliant on participants to report their dietary intake using food frequency questionnaires, which is not always reliable.

https://www.sciencedaily.com/releases/2021/05/210509153814.htm

Secret behind maintaining a healthy weight loss

May 6, 2021

Science Daily/University of Copenhagen - The Faculty of Health and Medical Sciences

Half of the Danish population have overweight, while 17 percent live with obesity. Worldwide, almost 40 procent have overweight and 13 procent live with obesity.

The condition is associated with increased risk for early death, as well as sequelae such as Type 2 diabetes, cardiovascular diseases, cancer, and infertility.

Weight regain after an initial successful weight loss in people with obesity, constitutes an important and unsolved problem. Until now, no well-documented study on which treatment method is best for maintaining a healthy weight loss has been available.

Researchers at University of Copenhagen and Hvidovre Hospital have completed a new, sensational study, which is being published in the world's most quoted medical journal, The New England Journal of Medicine. By testing four different types of treatment following a diet-induced weight loss, the researchers demonstrate for the first time how it is possible for people with obesity to maintain long-term weight loss, says Professor Signe Torekov at the Department of Biomedical Sciences.

In a randomized clinical trial, the group of researchers has demonstrated a highly effective treatment after a diet-induced weight loss, by combining moderate to vigorous-intensive exercise with appetite-inhibiting obesity medication, an analogue to the appetite-inhibiting hormone GLP-1.

"This is new knowledge for doctors, dietitians and physical therapists to use in practice. This is evidence that we have been missing," explains Signe Torekov, who has been heading the study.

"The problem is that people are fighting against strong biological forces when losing weight. The appetite increases simultaneously with decreased energy consumption, and this counteracts weight loss maintenance. We have an appetite-stimulating hormone, which increases dramatically when we lose weight, and simultaneously the level of appetite-suppressing hormones drops dramatically. In addition, a weight loss can provoke loss of muscle mass, while the body reduces the energy consumption. Thus, when the focus in obesity treatment has been on how to obtain a weight loss -- rather than how to maintain a weight loss -- it is really difficult to do something about your situation," says Signe Torekov.

Highly efficient when combining treatments

215 Danes with obesity and low fitness ratings participated in the study. The participants initially followed a low calorie diet over eight weeks, where they each lost approximately 13 kg, which brought significant improvements to their health with a drop in blood sugar level and blood pressure.

The participants were then randomly divided into four groups. Two of the groups received placebo medication, while the two other groups received obesity medication. Among the two placebo groups, one group followed an exercise program of minimum 150 minutes of physical activity at moderate intensity or 75 minutes at vigorous-intensity during the week or a combination of the two, while the other group maintained their current level of physical activity. The two groups receiving obesity medication were similarly divided into one group with and one group without an exercise program.

All participants in the study were weighed monthly and received nutritional and diet counseling with the focus on healthy weight loss according to the guidelines from the Danish health and food administrations.

After one year, the group with exercise alone and the group with obesity medication alone maintained the weight loss of 13 kg and health improvements. The placebo group gained half of the weight back with deterioration of all risk factors, for example for development of Type 2 diabetes and cardiovascular disease.

The most dramatic improvements occurred in the combination group, which followed the exercise program and received obesity medication. The researchers observed additional weight loss in this group, and the total weight loss was approximately 16 kg over one year. The health benefits were also double that of each of the single treatments, i.e., twice the loss of fat mass while preserving muscle mass, higher fitness ratings, reduced blood sugar and improved quality of life.

The two groups that exercised increased their fitness rating, lost fat mass, and gained muscle mass. This could indicate a healthier weight loss than for people, who had only lost fat mass without increasing the fitness rating.

"It is an important aspect to highlight, as you do not necessarily get a healthier body from losing weight if, at the same time, you lose a lot of muscle mass," says Signe Torekov.

"It is great news for public health that a significant weight loss can be maintained with exercise for approximately 115 minute per week performed mostly at vigorous-intensity, such as cycling. And that by combining exercise with obesity medication, the effect is twice as good as each of the individual treatments." "

With the study, the researchers now hope people with obesity, together with their care provider, can create a useful framework for maintaining the weight loss.

Fundamental lifestyle change

Signe Torekov points out that many people with obesity have tried to lose weight before, only to regain the weight. This happens, because the general advice is to eat healthier and exercise more.

"Without a follow-up on whether people actually have support to perform exercise, the treatment will not be enough. Therefore, we also followed up with the participants on an ongoing basis to ensure that they received the support they needed in order to exercise. That is necessary, because maintaining weight loss is extremely hard. People need to understand this. Once you have lost weight, you are not "cured." "The ongoing exercise and effort will likely need to continue for many years," says Signe Torekov.

"Our study also demonstrates that without a structured treatment plan, there is a high risk of gaining the weight back. There were 12 individual consultations over the course of a year, including weighing and diet advice from Danish authorities according to guidelines for healthy weight maintenance. This was just not enough for the placebo group without exercise program, in this group all health benefits gained by weight loss during the eight week program were gone after one year, despite frequent weighing and diet and nutritional counseling based on official guidelines." Torekov says.

According to Signe Torekov, this underscores the importance of participating in a mutual weight maintenance program based on feedback when starting a weight loss programme.

"Therefore, it is important that there is a system for supporting people with obesity in maintaining the lifestyle change. Our study can help with this, because we can say this actually works to doctors, dietitians and municipalities, if they create a structured, joint treatment plan with the individual using ongoing follow-ups," says Torekov.

https://www.sciencedaily.com/releases/2021/05/210506105344.htm

Salad or cheeseburger? Your co-workers shape your food choices

April 22, 2021

Science Daily/Massachusetts General Hospital

Employees' cafeteria purchases -- both healthy and unhealthy foods -- were influenced by their co-workers' food choices, found a large, two-year study of hospital employees. The study made innovative use of cash register data to gain insights into how individuals' social networks shape their health behavior. The research suggests we might structure future efforts aimed at improving population health by capitalizing on how one person's behavior influences another.

The foods people buy at a workplace cafeteria may not always be chosen to satisfy an individual craving or taste for a particular food. When co-workers are eating together, individuals are more likely to select foods that are as healthy -- or unhealthy -- as the food selections on their fellow employees' trays. "We found that individuals tend to mirror the food choices of others in their social circles, which may explain one way obesity spreads through social networks," says Douglas Levy, PhD, an investigator at the Mongan Institute Health Policy Research Center at Massachusetts General Hospital (MGH) and first author of new research published in Nature Human Behaviour. Levy and his co-investigators discovered that individuals' eating patterns can be shaped even by casual acquaintances, evidence that corroborates several multi-decade observational studies showing the influence of people's social ties on weight gain, alcohol consumption and eating behavior.

Previous research on social influence upon food choice had been primarily limited to highly controlled settings like studies of college students eating a single meal together, making it difficult to generalize findings to other age groups and to real-world environments. The study by Levy and his co-authors examined the cumulative social influence of food choices among approximately 6,000 MGH employees of diverse ages and socioeconomic status as they ate at the hospital system's seven cafeterias over two years. The healthfulness of employees' food purchases was determined using the hospital cafeterias' "traffic light" labeling system designating all food and beverages as green (healthy), yellow (less healthy) or red (unhealthy).

MGH employees may use their ID cards to pay at the hospitals' cafeterias, which allowed the researchers to collect data on individuals' specific food purchases, and when and where they purchased the food. The researchers inferred the participants' social networks by examining how many minutes apart two people made food purchases, how often those two people ate at the same time over many weeks, and whether two people visited a different cafeteria at the same time. "Two people who make purchases within two minutes of each other, for example, are more likely to know each other than those who make purchases 30 minutes apart," says Levy. And to validate the social network model, the researchers surveyed more than 1,000 employees, asking them to confirm the names of the people the investigators had identified as their dining partners.

"A novel aspect of our study was to combine complementary types of data and to borrow tools from social network analysis to examine how the eating behaviors of a large group of employees were socially connected over a long period of time," says co-author Mark Pachucki, PhD, associate professor of Sociology at the University of Massachusetts, Amherst.

Based on cross-sectional and longitudinal assessments of three million encounters between pairs of employees making cafeteria purchases together, the researchers found that food purchases by people who were connected to each other were consistently more alike than they were different. "The effect size was a bit stronger for healthy foods than for unhealthy foods," says Levy.

A key component of the research was to determine whether social networks truly influence eating behavior, or whether people with similar lifestyles and food preferences are more likely to become friends and eat together, a phenomenon known as homophily. "We controlled for characteristics that people had in common and analyzed the data from numerous perspectives, consistently finding results that supported social influence rather than homophily explanations," says Levy.

Why do people who are socially connected choose similar foods? Peer pressure is one explanation. "People may change their behavior to cement the relationship with someone in their social circle," says Levy. Co-workers may also implicitly or explicitly give each other license to choose unhealthy foods or exert pressure to make a healthier choice.

The study's findings have several broader implications for public health interventions to prevent obesity. One option may be to target pairs of people making food choices and offer two-for-one sales on salads and other healthful foods but no discounts on cheeseburgers. Another approach might be to have an influential person in a particular social circle model more healthful food choices, which will affect others in the network. The research also demonstrates to policymakers that an intervention that improves healthy eating in a particular group will also be of value to individuals socially connected to that group.

"As we emerge from the pandemic and transition back to in-person work, we have an opportunity to eat together in a more healthful way than we did before," says Pachucki. "If your eating habits shape how your co-workers eat -- even just a little -- then changing your food choices for the better might benefit your co-workers as well."

https://www.sciencedaily.com/releases/2021/04/210422150341.htm

Managing children's weight, blood pressure and cholesterol protects brain function mid-life

May 10, 2021

Science Daily/American Heart Association

Managing weight, blood pressure and cholesterol in children may help protect brain function in later life, according to new research published today in the American Heart Association's flagship journal Circulation. This is the first study to highlight that cardiovascular risk factors accumulated from childhood through mid-life may influence poor cognitive performance at midlife.

Previous research has indicated that nearly 1 in 5 people older than 60 have at least mild loss of brain function. Cognitive deficits are known to be linked with cardiovascular risk factors, such as high blood pressure, obesity, type 2 diabetes, smoking, physical inactivity and poor diet, as well as depression and low education level.

Many diseases that cause neurological deficits, such as Alzheimer's, have a long preclinical phase before noticeable symptoms begin, so finding links between childhood obesity and other cardiovascular risk factors is important for cognitive health. The researchers noted that there are currently no cures for major causes of dementia, so it is important to learn how early in life cardiovascular risk factors may affect the brain.

"We can use these results to turn the focus of brain health from old age and midlife to people in younger age groups," said the study's first author Juuso O. Hakala, M.D., a Ph.D. student at the Research Centre of Applied and Prevention Cardiovascular Medicine at the University of Turku, in Turku, Finland. "Our results show active monitoring and prevention of heart disease and stroke risk factors, beginning from early childhood, can also matter greatly when it comes to brain health. Children who have adverse cardiovascular risk factors might benefit from early intervention and lifestyle modifications."

The Cardiovascular Risk in Young Finns Study is a national, longitudinal study on cardiovascular risk from childhood to adulthood in Finland. Researchers followed the participants' cardiovascular risk factor profiles for 31 years from childhood to adulthood. Baseline clinical examinations were conducted in 1980 on approximately 3,600 randomly selected boys and girls, ranging in ages from 3 to 18, all of whom were white. More than 2,000 of the participants, ranging in ages from 34 to 49, underwent a computerized cognitive function test in 2011. The test measured four different cognitive domains: episodic memory and associative learning; short-term working memory; reaction and movement time; and visual processing and sustained attention.

Researchers found:

• Systolic blood pressure, total blood cholesterol and low-density lipoprotein (LDL) cholesterol, as well as body mass index, from childhood to midlife are associated with brain function in middle age.

• Consistently high systolic blood pressure or high blood total cholesterol and LDL cholesterol were linked to worse memory and learning by midlife when compared with lower measures.

• Obesity from childhood to adulthood was associated with lower visual information processing speed and maintaining attention.

• Having all three cardiovascular risk factors was linked to poorer memory and associative learning, worse visual processing, decreased attention span, and slower reaction and movement time.

These results are from observational findings, so more studies are needed to learn whether there are specific ages in childhood and/or adolescence when cardiovascular risk factors are particularly important to brain health in adulthood. Study limitations include that a definite cause-and-effect link between cardiovascular risk factors and cognitive performance cannot be determined in this type of population-based study; cognition was measured at a single point in time; and because all study participants are white, the results may not be generalizable to people from other racial or ethnic groups.

https://www.sciencedaily.com/releases/2021/05/210510085857.htm

How bullying and obesity can affect girls' and boys' mental health

May 7, 2021

Science Daily/Uppsala University

Depressive symptoms are more common in teenage girls than in their male peers. However, boys' mental health appears to be affected more if they suffer from obesity. Irrespective of gender, bullying is a considerably greater risk factor than overweight for developing depressive symptoms. These conclusions are drawn by researchers at Uppsala University who monitored adolescents for six years in a questionnaire study, now published in the Journal of Public Health.

"The purpose of our study was to investigate the connection between body mass index (BMI) and depressive symptoms, and to take a close look at whether being subjected to bullying affects this relationship over time. We also wanted to investigate whether any gender differences existed," says Sofia Kanders, a PhD student at Uppsala University's Department of Neuroscience.

In the study young people, born in Västmanland County, replied to questions about their height, weight and depressive symptoms on three separate occasions (2012, 2015 and 2018). The respondents' mean age was 14.4 years on the first occasion and 19.9 years on the last.

Based on BMI, the adolescents were divided into three groups: those with normal weight, overweight and obesity respectively. They were also grouped according to the extent of their depressive symptoms.

Overall, regardless of their weight, the girls stated more frequently that they had depressive symptoms. In 2012, 17 per cent of the girls and 6 per cent of the boys did so. By 2015, the proportions of adolescents with these symptoms had risen to 32 per cent for the girls and 13 per cent for the boys. The corresponding figures for 2018 were 34 and 19 per cent respectively.

A higher BMI did not, as far as the researchers could see, affect the girls' mental well-being to any great extent. Among the boys, however, the pattern observed was entirely different.

"When we analysed girls and boys separately, we saw that for boys with obesity in 2012, the risk for having depressive symptoms in 2015 was, statistically, five times higher than for normal-weight boys. In the girls we found no such connection," Kanders says.

The study has been unable to answer the question of what causes this gender difference, and the researchers think more research is needed in this area.

The young respondents were also asked about bullying -- for example, to state whether, in the past year, they had been physically exposed to blows and kicks, teased or excluded, subjected to cyberbullying (abusive texting or other electronic or web bullying), or bullied by an adult at school.

In every analysis, exposure to bullying was associated with a higher risk of depressive symptoms. This connection was also evident six years later, especially in overweight boys. The researchers believe that these results seem to indicate a gender difference in how BMI and bullying together drive development of future depressive symptoms.

"One key conclusion and take-home message from our study is that bullying can affect mental illness for a long time to come, which therefore makes preventive measures against bullying in schools extremely important," Kanders says.

Facts about the study 

This study is a sub-project in the much larger SALVe (Survey of Adolescent Life in Vestmanland) study. In SALVe, teenagers born in 1997 and 1999, and residing in Västmanland County (to the west of Uppsala), were asked in 2012 to answer questions about various ailments, well-being, sleep, computer habits, gaming, enjoyment of school and other aspects of their lives. The purpose is to follow this cohort for 20 years in order to gain knowledge of how inheritance and environment affect mental and physical health.

In this sub-project, 1,729 adolescents (962 girls and 767 boys) replied to the researchers' questions on the first occasion, in 2012. In 2015 there were 1,481 respondents, and in 2018 1,111. This decrease in numbers over time was due to drop-out, with slightly more boys than girls leaving the study.

The adolescents were grouped on the basis of their BMI and prevalence of depressive symptoms. Every answer to a question about the extent of their subjection to bullying was given a point score from 0 to 3. The researchers then compared the various groups' total scores; that is, they did not explore the results at individual level.

https://www.sciencedaily.com/releases/2021/05/210507112020.htm

Research shows consuming prebiotic supplements once a day has a positive impact on anxiety levels

April 27, 2021

Science Daily/University of Surrey

In a paper published in the journal Scientific Reports, researchers from Surrey investigated whether the daily consumption of a prebiotic food supplement could improve overall wellbeing in a group of 18 to 25 year-olds. The study found that those who received a daily dose of prebiotics improved mental wellbeing by reducing anxiety levels and had better gut health than the control group.

Researchers studied a group of 64 healthy female participants with no current or previous clinical diagnoses of anxiety. Participants received either a daily dose of the prebiotic galacto-oligosaccharides (GOS) or a placebo for 28 days.

All those involved in the trial completed surveys about their health experiences, including mood, anxiety and sleep quality and provided a stool sample for gut microbiome sequencing analysis.

Dr Kathrin Cohen Kadosh, Reader in Developmental Cognitive Neuroscience at the University of Surrey and Head of the Social Brain and Development Lab, said:

"This new research marks a significant step forward in that we were able to show that we can use a simple and safe food supplement such as prebiotics to improve both the abundance of beneficial gut bacteria in the gut and to improve mental health and wellbeing in young women."

Dr Nicola Johnstone, Research Fellow from the University of Surrey, said:

"This is an exciting study that brings together different dimensions in mental health research; finding prebiotic effects in a sub-clinical group shows promise for translational clinical research on multiple markers of mental health."

https://www.sciencedaily.com/releases/2021/04/210427122408.htm

Should You Start A Keto Diet?

Guest Post by John Mullen

 *Note: AV Stim is not endorsing any products or services through guest posts, thanks.

With everyone wanting a new and healthy lifestyle, people are wondering if the Keto diet is worth investing in. While the doctors who created Keto have said that they only recommend it for extreme situations concerning health, new studies are being done to determine if it's safe. So far, they have concluded more investigation is needed. However, with a doctor and coach to guide you, many people have been able to succeed. 

What Keto Is About

The Keto diet is meant to help your body in a new way. When wondering if you should start a Keto Diet, you will need to understand what it will do to you. A Keto diet is low carb, moderate protein, and tons of fat. The thought process behind this is that it is believed that you will be able to burn fat more effectively and offer your body additional benefits to utilize. Many doctors have said that this isn't a long-term solution, though others have said that it could be. 

The hope is that by adopting a higher fat content diet, your body will be using it as an alternative way to have fuel. When you eat fewer carbs or fewer calories, your liver is believed to produce what is known as ketones. Those ketones are then supposed to be a fuel source for your body to function more healthily. 

Who Should Never Attempt Keto

 Because of how Keto burns fat and how it affects glucose, if you have diabetes or take medication for this disease, you should never attempt this diet because it can put you into a state of life-threatening ketoacidosis. High blood pressure is another condition that makes this diet a no-go. The same is true if you take medication for it, are pregnant, or breastfeeding, you should never attempt this diet either as it can cause harm to you and your child. 

A Coach Can Help

Trusting a coach to help you through this journey will help you in the short and long term. A coach will guide you and allow you to make the best decisions for your body and mind while helping ensure that you stay in good health as long as possible. They will also ensure that you stop if your body can't take this diet. Exercise and watching your food will be another area that they can help. If you find this diet works for you, you may end up with a slimmer form. 

Dietary cocoa improves health of obese mice; likely has implications for humans

April 14, 2021

Science Daily/Penn State

Supplementation of cocoa powder in the diet of high-fat-fed mice with liver disease markedly reduced the severity of their condition, according to a new study by Penn State researchers, who suggest the results have implications for people.

Cocoa powder, a popular food ingredient most commonly used in the production of chocolate, is rich in fiber, iron and phytochemicals reported to have positive health benefits, including antioxidant polyphenols and methylxanthines, noted study leader Joshua Lambert, professor of food science in the College of Agricultural Sciences.

"While it is typically considered an indulgence food because of its high sugar and fat content, epidemiological and human-intervention studies have suggested that chocolate consumption is associated with reduced risk of cardio-metabolic diseases including stroke, coronary heart disease and Type 2 diabetes," Lambert said. "So, it made sense to investigate whether cocoa consumption had an effect on non-alcohol-related fatty liver disease, which is commonly associated with human obesity."

This study has several strengths, Lambert explained. It used a commercially available cocoa product at a "physiologically achievable dose" -- meaning its equivalent could be duplicated by humans. "Doing the calculations, for people it works out to about 10 tablespoons of cocoa powder a day," he said. "Or, if you follow the directions on the Hershey's box of cocoa powder, that's about five cups of hot cocoa a day."

The high-fat-fed mouse is a well-established, diet-induced model of obesity, Lambert added. By waiting until mice were already obese before beginning cocoa treatment, researchers were able to test the protective effects of cocoa in a model that better simulates the current public health situation related to non-alcohol-related fatty liver disease.

That's important, Lambert pointed out, because a significant proportion of the world's population has preexisting obesity and non-alcohol-related fatty liver disease. "Given the high proportion of people in the United States and other parts of the world with obesity, there is a need to develop potentially effective dietary interventions rather than just preventive agents," he said.

For this study, researchers examined changes in fatty liver disease, markers of oxidative stress, antioxidant response and cell damage in high-fat-fed obese mice treated with a diet supplemented with 80 mg cocoa powder per gram of food -- roughly a pinch per quarter teaspoon -- for eight weeks.

In findings recently published in the Journal of Nutritional Biochemistry, the researchers reported that cocoa-treated mice gained weight at a 21% lower rate and had smaller spleen weights -- indicating less inflammation -- than the high-fat-fed control mice. At the end of the study, mice fed the cocoa-powder-supplemented diet had 28% less fat in their livers than the control mice. Cocoa-treated mice also had 56% lower levels of oxidative stress and 75% lower levels of DNA damage in the liver compared to high-fat-fed control mice.

The mechanisms by which cocoa imparts health benefits are not well understood, but previous studies in Lambert's lab showed that extracts from cocoa and some of the chemicals in cocoa powder can inhibit the enzymes that are responsible for digesting dietary fat and carbohydrate.

The result, he proposes, is that when mice get cocoa as part of their diet, these compounds in the cocoa powder prevent the digestion of dietary fat. When it can't be absorbed, the fat passes through their digestive systems. A similar process may occur with cocoa in humans, he hypothesizes.

In view of this new information about cocoa powder, Lambert is not recommending that obese people -- or anyone -- simply add five cups of hot cocoa to their daily routine and change nothing else in their diet. But he does advise, based on what he has learned in this study, to consider substituting cocoa for other foods, particularly high-calorie snack foods.

"This exchange is potentially beneficial, especially in combination with a healthy overall diet and increased physical activity," he said. "If you go to the gym and work out, and your reward is you go home and have a cup of cocoa, that may be something that helps get you off the couch and moving around."

Also involved in the research were Mingyao Sun, Yeyi Gu and Shannon Glisan, former graduate students in the Department of Food Science.

https://www.sciencedaily.com/releases/2021/04/210414154933.htm

Late night snacks may hurt your workplace performance

April 7, 2021

Science Daily/North Carolina State University

A recent study finds that unhealthy eating behaviors at night can make people less helpful and more withdrawn the next day at work.

"For the first time, we have shown that healthy eating immediately affects our workplace behaviors and performance," says Seonghee "Sophia" Cho, corresponding author of the study and an assistant professor of psychology at North Carolina State University. "It is relatively well established that other health-related behaviors, such as sleep and exercise, affect our work. But nobody had looked at the short-term effects of unhealthy eating."

Fundamentally, the researchers had two questions: Does unhealthy eating behavior affect you at work the next day? And, if so, why?

For the study, researchers had 97 full-time employees in the United States answer a series of questions three times a day for 10 consecutive workdays. Before work on each day, study participants answered questions related to their physical and emotional well-being. At the end of each workday, participants answered questions about what they did at work. In the evening, before bed, participants answered questions about their eating and drinking behaviors after work.

In the context of the study, researchers defined "unhealthy eating" as instances when study participants felt they'd eaten too much junk food; when participants felt they'd had too much to eat or drink; or when participants reporting having too many late-night snacks.

The researchers found that, when people engaged in unhealthy eating behaviors, they were more likely to report having physical problems the next morning. Problems included headaches, stomachaches and diarrhea. In addition, when people reported unhealthy eating behaviors, they were also more likely to report emotional strains the next morning -- such as feeling guilty or ashamed about their diet choices. Those physical and emotional strains associated with unhealthy eating were, in turn, related to changes in how people behaved at work throughout the day.

Essentially, when people reported physical or emotional strains associated with unhealthy eating, they were also more likely to report declines in "helping behavior" and increases in "withdrawal behavior." Helping behavior at work refers to helping colleagues and going the extra mile when you don't have to, such as assisting a co-worker with a task that is not your responsibility. Withdrawal behavior refers to avoiding work-related situations, even though you're at your workplace.

The researchers also found that people who were emotionally stable -- meaning people who are better able to cope with stress because they're less emotionally volatile -- suffered fewer adverse effects from unhealthy eating. Not only were emotionally stable people less likely to have physical or emotional strains after unhealthy eating, their workplace behaviors were also less likely to change even when they reported physical or emotional strains.

"The big takeaway here is that we now know unhealthy eating can have almost immediate effects on workplace performance," Cho says. "However, we can also say that there is no single 'healthy' diet, and healthy eating isn't just about nutritional content. It may be influenced by an individual's dietary needs, or even by when and how they're eating, instead of what they're eating.

"Companies can help to address healthy eating by paying more attention to the dietary needs and preferences of their employees and helping to address those needs, such as through on-site dining options. This can affect both the physical and mental health of their employees -- and, by extension, their on-the-job performance."

The researchers also pointed to a variety of research questions that could be addressed moving forward.

"One confounding variable is that the way our questions were phrased, we may be capturing both unhealthy eating behaviors and unhealthy drinking behaviors related to alcohol," Cho says.

"That's something we will want to tease out moving forward. And while we focused on evening diet, it would be interesting to look at what people are eating at other times of day. Are there specific elements of diet that affect behavioral outcomes -- such as sugar or caffeine content? Can there be positive effects of unhealthy eating, such as when people eat comfort foods to help cope with stress? This promises to be a rich field of study."

https://www.sciencedaily.com/releases/2021/04/210407135755.htm

More protein doesn't mean more strength in resistance-trained middle-aged adults

March 25, 2021

Science Daily/University of Illinois at Urbana-Champaign, News Bureau

A 10-week muscle-building and dietary program involving 50 middle-aged adults found no evidence that eating a high-protein diet increased strength or muscle mass more than consuming a moderate amount of protein while training. The intervention involved a standard strength-training protocol with sessions three times per week. None of the participants had previous weightlifting experience.

Published in the American Journal of Physiology: Endocrinology and Metabolism, the study is one of the most comprehensive investigations of the health effects of diet and resistance training in middle-aged adults, the researchers say. Participants were 40-64 years of age.

The team assessed participants' strength, lean-body mass, blood pressure, glucose tolerance and several other health measures before and after the program. They randomized participants into moderate- and high-protein diet groups. To standardize protein intake, the researchers fed each person a freshly cooked, minced beef steak and carbohydrate beverage after every training session. They also sent participants home with an isolated-protein drink to be consumed every evening throughout the 10 weeks of the study.

"The moderate-protein group consumed about 1.2 grams of protein per kilogram of body weight per day, and the high-protein group consumed roughly 1.6 grams per kilogram per day," said Colleen McKenna, a graduate student in the division of nutritional sciences and registered dietician at the University of Illinois Urbana-Champaign who led the study with U. of I. kinesiology and community health professor Nicholas Burd. The team kept calories equivalent in the meals provided to the two groups with additions of beef tallow and dextrose.

The study subjects kept food diaries and McKenna counseled them every other week about their eating habits and protein intake.

In an effort led by U. of I. food science and human nutrition professor Hannah Holscher, the team also analyzed gut microbes in fecal samples collected at the beginning of the intervention, after the first week -- during which participants adjusted to the new diet but did not engage in physical training -- and at the end of the 10 weeks. Previous studies have found that diet alone or endurance exercise alone can alter the composition of microbes in the digestive tract.

"The public health messaging has been that Americans need more protein in their diet, and this extra protein is supposed to help our muscles grow bigger and stronger," Burd said. "Middle age is a bit unique in that as we get older, we lose muscle and, by default, we lose strength. We want to learn how to maximize strength so that as we get older, we're better protected and can ultimately remain active in family and community life."

The American Food and Nutrition Board recommends that adults get 0.8 grams of protein per kilogram of body weight per day to avoid developing a protein deficiency. The team tried to limit protein consumption in the moderate-protein group to the Recommended Daily Allowance, but their food diaries revealed those participants were consuming, on average, 1.1 to 1.2 grams of protein per kilogram of body weight per day. Those in the high-protein group ate about 1.6 grams of protein per kilogram per day -- twice the recommended amount.

Burd and his colleagues hypothesized that getting one's protein from a high-quality source like beef and consuming significantly more protein than the RDA would aid in muscle growth and strength in middle-aged adults engaged in resistance training. But at the end of the 10 weeks, the team saw no significant differences between the groups. Their gains in strength, their body fat, lean body mass, glucose tolerance, kidney function, bone density and other "biomarkers" of health were roughly the same.

The only potentially negative change researchers recorded between the groups involved alterations to the population of microbes that inhabit the gut. After one week on the diet, those in the high-protein group saw changes in the abundance of some gut microbes that previous studies have linked to negative health outcomes. Burd and his colleagues found that their strength-training intervention reversed some of these changes, increasing beneficial microbes and reducing the abundance of potentially harmful ones.

"We found that high protein intake does not further increase gains in strength or affect body composition," Burd said. "It didn't increase lean mass more than eating a moderate amount of protein. We didn't see more fat loss, and body composition was the same between the groups. They got the gain in weight, but that weight gain was namely from lean-body-mass gain."

Burd said the finding makes him question the push to increase protein intake beyond 0.8-1.1 grams per kilogram of body weight, at least in middle-aged weightlifters consuming high-quality animal-based protein on a regular basis.

McKenna said the team's multidisciplinary approach and in-depth tracking of participants' dietary habits outside the laboratory makes it easier to understand the findings and apply them to daily life.

"We have recommendations for healthy eating and we have recommendations for how you should exercise, but very little research looks at how the two together impact our health," she said. The study team included exercise physiologists, registered dietitians and experts on gut microbiology.

"This allowed us to address every aspect of the intervention in the way it should be addressed," McKenna said. "We're honoring the complexity of human health with the complexity of our research."

https://www.sciencedaily.com/releases/2021/03/210325101256.htm

Cells burn more calories after just one bout of moderate aerobic exercise

March 22, 2021

Science Daily/Oregon State University

In a recent study testing the effects of exercise on overall metabolism, researchers at Oregon State University found that even a single session of moderate aerobic exercise makes a difference in the cells of otherwise sedentary people.

Mitochondria are the part of the cell responsible for the biological process of respiration, which turns fuels such as sugars and fats into energy, so the researchers focused only on mitochondria function.

"What we found is that, regardless of what fuel the mitochondria were using, there were mild increases in the ability to burn off the fuels," said Matt Robinson, lead author on the study and an assistant professor in the College of Public Health and Human Sciences.

OSU researchers recruited participants who do not follow a regular exercise routine and had them ride a stationary bike for an hour at a moderate intensity. They biopsied their muscles 15 minutes later to test how efficient the mitochondria were after the exercise was completed and compared those results with a resting day.

Post-exercise, study participants' mitochondria burned 12-13% more fat-based fuel and 14-17% more sugar-based fuel. While the effects were not drastic, they were consistent, Robinson said.

"It's pretty remarkable that even after just one hour of exercise, these people were able to burn off a little more fuel," he said.

Previous research in the field has long established that regular exercise creates lasting change in people's metabolism, making their bodies burn more energy even when they're not working out.

Prior studies have looked at highly trained or athletic people, but Robinson's team wanted to look specifically at singular bouts of exercise in people who were generally active and disease-free but who did not have structured exercise regimes. These people were on the lower end of fitness, which is associated with low mitochondrial abundance and energy production. Participants were monitored while working out at approximately 65% of their maximal effort, where they could keep up the cycling pace for an hour or more and still comfortably carry on a conversation.

Robinson said they're hoping these results help break down the mental barrier of people thinking they need to be elite athletes for exercise to make an impact on their health.

"From a big picture health perspective, it's very encouraging for people to realize that you can get health benefits from a single session of exercise," Robinson said. "We're trying to encourage people, 'You did one, why don't you try to do two? Let's do three.'

"We know that exercise is good for you, in general. But those benefits of that single bout of exercise seem to fade away after a day or two. You get the long-term benefits when you do that exercise again and again and you make it a regular habit."

In this study, Robinson's research team focused narrowly on mitochondria to find out how big a role mitochondria play in the overall function of muscle metabolism. Other studies are looking at changes in blood flow to the muscle and how the muscle metabolizes fats versus sugars.

From a disease perspective, Robinson said it's clear that obesity and diabetes involve impairments in metabolism. Physiologically, when the body undergoes exercise, sugars tend to be burned off first while fats are stored, but in cases of diabetes and obesity, there is some dysregulation in metabolism that causes the body to not be able to switch between the two types of fuel.

Exercise can help reset that system, he said.

"Since those get burned off in the mitochondria, our hope is that with exercise, we could increase the mitochondria and then improve how the body burns off fats and sugars," he said.

https://www.sciencedaily.com/releases/2021/03/210322085520.htm

Eating processed meat could increase dementia risk

March 21, 2021

Science Daily/University of Leeds

Scientists from the University's Nutritional Epidemiology Group used data from 500,000 people, discovering that consuming a 25g serving of processed meat a day, the equivalent to one rasher of bacon, is associated with a 44% increased risk of developing the disease.

But their findings also show eating some unprocessed red meat, such as beef, pork or veal, could be protective, as people who consumed 50g a day were 19% less likely to develop dementia. 

The researchers were exploring whether there is a link between consumption of meat and development of dementia, a health condition which affects 5%-8% of over 60s worldwide.

Their results, titled Meat consumption and risk of incident dementia: cohort study of 493,888 UK Biobank participants, are published today in the American Journal of Clinical Nutrition.

Lead researcher Huifeng Zhang, a PhD student from Leeds' School of Food Science and Nutrition, said: "Worldwide, the prevalence of dementia is increasing and diet as a modifiable factor could play a role.

"Our research adds to the growing body of evidence linking processed meat consumption to increased risk of a range of non-transmissible diseases." 

The research was supervised by Professors Janet Cade and Laura Hardie, both at Leeds.

The team studied data provided by UK Biobank, a database containing in-depth genetic and health information from half a million UK participants aged 40 to 69, to investigate associations between consuming different types of meat and risk of developing dementia.  

The data included how often participants consumed different kinds of meat, with six options from never to once or more daily, collected in 2006-2010 by the UK Biobank. The study did not specifically assess the impact of a vegetarian or vegan diet on dementia risk, but it included data from people who said they did not eat red meat. 

Among the participants, 2,896 cases of dementia emerged over an average of eight years of follow up. These people were generally older, more economically deprived, less educated, more likely to smoke, less physically active, more likely to have stroke history and family dementia history, and more likely to be carriers of a gene which is highly associated with dementia. More men than women were diagnosed with dementia in the study population.  

Some people were three to six times more likely to develop dementia due to well established genetic factors, but the findings suggest the risks from eating processed meat were the same whether or not a person was genetically predisposed to developing the disease. 

Those who consumed higher amounts of processed meat were more likely to be male, less educated, smokers, overweight or obese, had lower intakes of vegetables and fruits, and had higher intakes of energy, protein, and fat (including saturated fat). 

Meat consumption has previously been associated with dementia risk, but this is believed to be the first large-scale study of participants over time to examine a link between specific meat types and amounts, and the risk of developing the disease. 

There are around 50 million dementia cases globally, with around 10 million new cases diagnosed every year. Alzheimer's Disease makes up 50% to 70% of cases, and vascular dementia around 25%. Its development and progression are associated with both genetic and environmental factors, including diet and lifestyle.  

Ms Zhang said: "Further confirmation is needed, but the direction of effect is linked to current healthy eating guidelines suggesting lower intakes of unprocessed red meat could be beneficial for health."

Professor Cade said: "Anything we can do to explore potential risk factors for dementia may help us to reduce rates of this debilitating condition. This analysis is a first step towards understanding whether what we eat could influence that risk."

https://www.sciencedaily.com/releases/2021/03/210321215434.htm

Changes in mouth bacteria after drinking beetroot juice may promote healthy aging

March 30, 2021

Science Daily/University of Exeter

Drinking beetroot juice promotes a mix of mouth bacteria associated with healthier blood vessels and brain function, according to a new study of people aged 70-80.

Beetroot -- and other foods including lettuce, spinach and celery -- are rich in inorganic nitrate, and many oral bacteria play a role in turning nitrate to nitric oxide, which helps to regulate blood vessels and neurotransmission (chemical messages in the brain).

Older people tend to have lower nitric oxide production, and this is associated with poorer vascular (blood vessel) and cognitive (brain) health.

In the new study, by the University of Exeter, 26 healthy older people took part in two ten-day supplementation periods: one with nitrate-rich beetroot juice and another with nitrate-free placebo juice, which they drank twice a day.

The results showed higher levels of bacteria associated with good vascular and cognitive health, and lower levels of bacteria linked to disease and inflammation.

Systolic blood pressure dropped on average by five points (mmHg) after drinking the beetroot juice.

"We are really excited about these findings, which have important implications for healthy ageing," said lead author Professor Anni Vanhatalo, of the University of Exeter.

"Previous studies have compared the oral bacteria of young and older people, and healthy people compared to those with diseases, but ours is the first to test nitrate-rich diet in this way.

"Our findings suggest that adding nitrate-rich foods to the diet -- in this case via beetroot juice -- for just ten days can substantially alter the oral microbiome (mix of bacteria) for the better.

"Maintaining this healthy oral microbiome in the long term might slow down the negative vascular and cognitive changes associated with ageing."

The researchers ran tests to identify clusters (or "modules") of oral bacteria that tend to thrive together in similar conditions.

A module (Prevotella-Veillonella) that has been associated with inflammation was reduced after nitrate supplementation, including a decrease of Clostridium difficile (which can infect the bowel and cause diarrhea).

Professor Vanhatalo stressed that more research is needed to confirm the findings and see whether similar effects are found in other groups.

"Our participants were healthy, active older people with generally good blood pressure," she said. "Dietary nitrate reduced their blood pressure on average, and we are keen to find out whether the same would happen in other age groups and among people in poorer health.

"We are working with colleagues in the University of Exeter Medical School to investigate interactions between the oral bacteria and cognition to better understand the how diet could be used to delay cognitive decline in older age."

Much research has been conducted into the benefits of a healthy gut microbiome, but far less is known about the oral microbial community, which plays a crucial role in "activating" the nitrate from a vegetable-rich diet.

https://www.sciencedaily.com/releases/2021/03/210330121231.htm