Positive parenting can reduce the risk that children develop obesity

February 22, 2022

Science Daily/Penn State

New research from Penn State found that children with positive, early interactions with their care givers -- characterized by warmth, responsiveness, and a sitmulating home environment -- were at reduced risk of childhood obesity.

"A lot of the discussion around childhood obesity and other health risks focuses on identifying and studying the exposure to risk," said Brandi Rollins, assistant research professor of biobehavioral health. "We took a strength-based approach in our analysis. We found that a supportive family and environment early in a child's life may outweigh some of the cumulative risk factors that children can face."

The study, "Family Psychosocial Assets, Child Behavioral Regulation, and Obesity," recently appeared in the journal Pediatrics. In the article, Rollins and Lori Francis, associate professor of biobehavioral health, analyzed data from over 1,000 mother-child pairs and found that children's early exposures to family psychosocial assets -- including a quality home environment, emotional warmth from the mother, and a child's ability to self-regulate -- reduced the risk of developing childhood obesity.

Encouragingly, these factors were protective even when children faced familial risks for obesity, including poverty, maternal depression, or residence in a single-parent home.

"Research on parenting has shown that these types of family assets influence children's behavior, academic success, career, and -- not surprisingly -- health," Rollins said. "It is significant that these factors also protect against childhood obesity because the family assets we studied are not food or diet-specific at all. It is heartening to know that, by providing a loving, safe environment, we can reduce the risk that children will develop obesity."

Severe obesity

Children are deemed to have obesity when their body mass indices (BMIs) are greater than 95% of other children their age and gender. There is a great deal of variance, however, in the BMIs of children who exceed the obesity threshold. Children whose BMI is 20% higher than the obesity threshold are considered to have severe obesity.

The researchers found that children who had early-onset severe obesity did not face greater levels of family risk than children who were not obese. Children with severe obesity, however, did have fewer family assets than children who were not obese or who displayed moderate levels of obesity. More research is needed to understand which factors contribute to the development of severe obesity and which factors reduce the risk.

"Though the findings on severe obesity may seem discouraging, they offer some hope," Rollins explained. "Some risk factors, like household poverty, can be very difficult to change. Assets, on the other hand, may be easier to build. People can learn to parent responsively. It is encouraging that parenting really matters, that family matters."

What parents can do

This work is based on research in parenting and child development. Responsive parenting, one of the family assets measured in the study, involves responding to children in a timely, sensitive, and age-appropriate manner based on the child's presenting needs. Researchers in Penn State's Center for Childhood Obesity Research are also exploring how responsive parenting can reduce the risk of childhood obesity.

This study focused on childhood obesity, but the researchers said that parents may improve many outcomes for their children by learning responsive-parenting skills. Knowledge of responsive-parenting skills, however, may not lead directly to implementing those skills in the home.

"No one can read a pamphlet about cars and suddenly expect to drive," said Rollins. "Driving is a skill that requires education and practice. The same is true of responsive parenting.

"Public health professionals, clinicians, and researchers must collaborate to help families develop psychosocial assets, including responsive parenting and a structured home environment," she continued. "This could improve childhood obesity rates and other important quality-of-life outcomes."

https://www.sciencedaily.com/releases/2022/02/220222135155.htm

Link between high cholesterol and heart disease 'inconsistent'

March 14, 2022

Science Daily/RCS

New research from RCSI University of Medicine and Health Sciences has revealed that the link between 'bad' cholesterol (LDL-C) and poor health outcomes, such as heart attack and stroke, may not be as strong as previously thought.

Published in JAMA Internal Medicine, the research questions the efficacy of statins when prescribed with the aim of lowering LDL-C and therefore reducing the risk of cardiovascular disease (CVD).

Previous research has suggested that using statins to lower LDL-C positively affects health outcomes, and this is reflected in the various iterations of expert guidelines for the prevention of CVD. Statins are now commonly prescribed by doctors, with one third of Irish adults over the age of 50 taking statins, according to previous research.

The new findings contradict this theory, finding that this relationship was not as strong as previously thought. Instead, the research demonstrates that lowering LDL-C using statins had an inconsistent and inconclusive impact on CVD outcomes such as myocardial infarction (MI), stoke, and all-cause mortality.

In addition, it indicates that the overall benefit of taking statins may be small and will vary depending on an individual's personal risk factors.

The lead author on the paper is Dr Paula Byrne from the HRB Centre for Primary Care Research based in RCSI's Department of General Practice. Commenting on the findings, Dr Byrne said: "The message has long been that lowering your cholesterol will reduce your risk of heart disease, and that statins help to achieve this. However, our research indicates that, in reality, the benefits of taking statins are varied and can be quite modest."

The researchers go on to suggest that this updated information should be communicated to patients through informed clinical decision-making and updated clinical guidelines and policy.

https://www.sciencedaily.com/releases/2022/03/220314120702.htm

Psilocybin treatment for major depression effective for up to a year for most patients

February 15, 2022

Science Daily/Johns Hopkins Medicine

Previous studies by Johns Hopkins Medicine researchers showed that psychedelic treatment with psilocybin relieved major depressive disorder symptoms in adults for up to a month. Now, in a follow-up study of those participants, the researchers report that the substantial antidepressant effects of psilocybin-assisted therapy, given with supportive psychotherapy, may last at least a year for some patients.

A report on the new study was published on Feb. 15, 2022 in the Journal of Psychopharmacology.

"Our findings add to evidence that, under carefully controlled conditions, this is a promising therapeutic approach that can lead to significant and durable improvements in depression," says Natalie Gukasyan, M.D., assistant professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine. She cautions, however, that "the results we see are in a research setting and require quite a lot of preparation and structured support from trained clinicians and therapists, and people should not attempt to try it on their own."

Over the last 20 years, there has been a growing renaissance of research with classic psychedelics -- the pharmacological class of compounds that include psilocybin, an ingredient found in so-called magic mushrooms. According to the National Institute on Drug Abuse, psilocybin can produce perceptual changes, altering a person's awareness of their surroundings and of their thoughts and feelings. Treatment with psilocybin has shown promise in research settings for treating a range of mental health disorders and addictions.

For this study, the researchers recruited 27 participants with a long-term history of depression, most of whom had been experiencing depressive symptoms for approximately two years before recruitment. The average age of participants was 40, 19 were women, and 25 identified as white, one as African American and one as Asian. Eighty-eight percent of the participants had previously been treated with standard antidepressant medications, and 58% reported using antidepressants in their current depressive episodes.

After screening, participants were randomized into one of two groups in which they received the intervention either immediately, or after an eight-week waiting period. At the time of treatment, all participants were provided with six to eight hours of preparatory meetings with two treatment facilitators. Following preparation, participants received two doses of psilocybin, given approximately two weeks apart between August 2017 and April 2019 at the Behavioral Biology Research Center at Johns Hopkins Bayview Medical Center. Participants returned for follow-up one day and one week after each session, and then at one, three, six and 12 months following the second session; 24 participants completed both psilocybin sessions and all follow-up assessment visits.

The researchers reported that psilocybin treatment in both groups produced large decreases in depression, and that depression severity remained low one, three, six and 12 months after treatment. Depressive symptoms were measured before and after treatment using the GRID-Hamilton Depression Rating Scale, a standard depression assessment tool, in which a score of 24 or more indicates severe depression, 17-23 moderate depression, 8-16 mild depression and 7 or less no depression. For most participants, scores for the overall treatment decreased from 22.8 at pretreatment to 8.7 at one week, 8.9 at four weeks, 9.3 at three months, 7 at six months and 7.7 at 12 months after treatment. Participants had stable rates of response to the treatment and remission of symptoms throughout the follow-up period, with 75% response and 58% remission at 12 months.

"Psilocybin not only produces significant and immediate effects, it also has a long duration, which suggests that it may be a uniquely useful new treatment for depression," says Roland Griffiths, Ph.D., the Oliver Lee McCabe III, Ph.D., Professor in the Neuropsychopharmacology of Consciousness at the Johns Hopkins University School of Medicine, and founding director of the Johns Hopkins Center for Psychedelic and Consciousness Research. "Compared to standard antidepressants, which must be taken for long stretches of time, psilocybin has the potential to enduringly relieve the symptoms of depression with one or two treatments."

The researchers emphasize that further research is needed to explore the possibility that the efficacy of psilocybin treatment may be substantially longer than 12 months. Johns Hopkins is one of the sites of a national multisite randomized, placebo-controlled trial of psilocybin for major depressive disorder.

https://www.sciencedaily.com/releases/2022/02/220215090157.htm

Calorie restriction trial reveals key factors in extending human health

February 10, 2022

Science Daily/Yale University

Decades of research has shown that limits on calorie intake by flies, worms, and mice can enhance life span in laboratory conditions. But whether such calorie restriction can do the same for humans remains unclear. Now a new study led by Yale researchers confirms the health benefits of moderate calorie restrictions in humans -- and identifies a key protein that could be harnessed to extend health in humans.

The findings were published Feb. 10 in Science.

The research was based on results from the Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy (CALERIE) clinical trial, the first controlled study of calorie restriction in healthy humans. For the trial, researchers first established baseline calorie intake among more than 200 study participants. The researchers then asked a share of those participants to reduce their calorie intake by 14% while the rest continued to eat as usual, and analyzed the long-term health effects of calorie restriction over the next two years.

The overall aim of the clinical trial was to see if calorie restriction is as beneficial for humans as it is for lab animals, said Vishwa Deep Dixit, the Waldemar Von Zedtwitz Professor of Pathology, Immunobiology, and Comparative Medicine, and senior author of the study. And if it is, he said, researchers wanted to better understand what calorie restriction does to the body specifically that leads to improved health.

Since previous research has shown that calorie restriction in mice can increase infections, Dixit also wanted to determine how calorie restriction might be linked to inflammation and the immune response.

"Because we know that chronic low-grade inflammation in humans is a major trigger of many chronic diseases and, therefore, has a negative effect on life span," said Dixit, who is also director of the Yale Center for Research on Aging. "Here we're asking: What is calorie restriction doing to the immune and metabolic systems and if it is indeed beneficial, how can we harness the endogenous pathways that mimic its effects in humans?"

Dixit and his team started by analyzing the thymus, a gland that sits above the heart and produces T cells, a type of white blood cell and an essential part of the immune system. The thymus ages at a faster rate than other organs. By the time healthy adults reach the age of 40, said Dixit, 70% of the thymus is already fatty and nonfunctional. And as it ages, the thymus produces fewer T cells. "As we get older, we begin to feel the absence of new T cells because the ones we have left aren't great at fighting new pathogens," said Dixit. "That's one of the reasons why elderly people are at greater risk for illness."

For the study, the research team used magnetic resonance imaging (MRI) to determine if there were functional differences between the thymus glands of those who were restricting calories and those who were not. They found that the thymus glands in participants with limited calorie intake had less fat and greater functional volume after two years of calorie restriction, meaning they were producing more T cells than they were at the start of the study. But participants who weren't restricting their calories had no change in functional volume.

"The fact that this organ can be rejuvenated is, in my view, stunning because there is very little evidence of that happening in humans," said Dixit. "That this is even possible is very exciting."

With such a dramatic effect on the thymus, Dixit and his colleagues expected to also find effects on the immune cells that the thymus was producing, changes that might underlie the overall benefits of calorie restriction. But when they sequenced the genes in those cells, they found there were no changes in gene expression after two years of calorie restriction.

This observation required the researchers to take a closer look, which revealed a surprising finding: "It turns out that the action was really in the tissue microenvironment not the blood T cells," Dixit said.

Dixit and his team had studied adipose tissue, or body fat, of participants undergoing calorie restriction at three time points: at the beginning of the study, after one year, and after two. Body fat is very important, Dixit said, because it hosts a robust immune system. There are several types of immune cells in fat, and when they are aberrantly activated, they become a source of inflammation, he explained.

"We found remarkable changes in the gene expression of adipose tissue after one year that were sustained through year two," said Dixit. "This revealed some genes that were implicated in extending life in animals but also unique calorie restriction-mimicking targets that may improve metabolic and anti-inflammatory response in humans."

Recognizing this, the researchers then set out to see if any of the genes they identified in their analysis might be driving some of the beneficial effects of calorie restriction. They honed in on the gene for PLA2G7 -- or group VII A platelet activating factor acetylhydrolase -- which was one of the genes significantly inhibited following calorie restriction. PLA2G7 is a protein produced by immune cells known as macrophages.

This change in PLA2G7 gene expression observed in participants who were limiting their calorie intake suggested the protein might be linked to the effects of calorie restriction. To better understand if PLA2G7 caused some of the effects observed with calorie restriction, the researchers also tracked what happened when the protein was reduced in mice in a laboratory experiment.

"We found that reducing PLA2G7 in mice yielded benefits that were similar to what we saw with calorie restriction in humans," said Olga Spadaro, a former research scientist at the Yale School of Medicine and lead author of the study. Specifically, the thymus glands of these mice were functional for a longer time, the mice were protected from diet-induced weight gain, and they were protected from age-related inflammation.

These effects occurred because PLA2G7 targets a specific mechanism of inflammation called the NLRP3 inflammasome, researchers said. Lowering PLA2G7 protected aged mice from inflammation.

"These findings demonstrate that PLA2G7 is one of the drivers of the effects of calorie restriction," said Dixit. "Identifying these drivers helps us understand how the metabolic system and the immune system talk to each other, which can point us to potential targets that can improve immune function, reduce inflammation, and potentially even enhance healthy lifespan."

For instance, it might be possible to manipulate PLA2G7 and get the benefits of calorie restriction without having to actually restrict calories, which can be harmful for some people, he said.

"There's so much debate about what type of diet is better -- low carbohydrates or fat, increased protein, intermittent fasting, etc. -- and I think time will tell which of these are important," said Dixit. "But CALERIE is a very well-controlled study that shows a simple reduction in calories, and no specific diet, has a remarkable effect in terms of biology and shifting the immuno-metabolic state in a direction that's protective of human health. So from a public health standpoint, I think it gives hope."

https://www.sciencedaily.com/releases/2022/02/220210154204.htm

Eating prunes may help protect against bone loss in older women

February 9, 2022

Science Daily/Penn State

It's already well known that prunes are good for your gut, but new Penn State research suggests they may be good for bone health, too.

In a research review, the researchers found that prunes can help prevent or delay bone loss in postmenopausal women, possibly due to their ability to reduce inflammation and oxidative stress, both of which contribute to bone loss.

"In postmenopausal women, lower levels of estrogen can trigger a rise of oxidative stress and inflammation, increasing the risk of weakening bones that may lead to fractures," said Connie Rogers, associate professor of nutritional sciences and physiology. "Incorporating prunes into the diet may help protect bones by slowing or reversing this process."

The review was recently published in the journal Advances in Nutrition.

Osteoporosis is a condition in which bones become weak or brittle that can happen to anyone at any age, but according to the researchers is most common among women over the age of 50. The condition affects more than 200 million women worldwide, causing almost nine million fractures each year.

While medications exist to treat osteoporosis, the researchers said there is a growing interest for ways to treat the condition with nutrition.

"Fruits and vegetables that are rich in bioactive compounds such as phenolic acid, flavonoids and carotenoids can potentially help protect against osteoporosis," said Mary Jane De Souza, professor of kinesiology and physiology, "with prunes in particular gaining attention in previous research."

According to the researchers, bones are maintained throughout adult life by processes that continually build new bone cells while removing old ones. But after the age of 40, this breaking down of old cells begins to outpace the formation of new ones. This can be caused by multiple factors including inflammation and oxidative stress, which is when free radicals and antioxidants are unbalanced in the body.

Prunes, however, have many nutritional benefits such as minerals, vitamin K, phenolic compounds and dietary fiber -- all which may be able to help counter some of these effects.

For their review, the researchers analyzed data from 16 preclinical studies in rodent models, ten preclinical studies and two clinical trials. Across the studies, the researchers found evidence that eating prunes helped reduce inflammation and oxidative stress and promoted bone health.

For example, the clinical trials found that eating 100 grams of prunes -- about 10 prunes -- each day for one year improved bone mineral density of bones in the forearm and lower spine and decreased signs of bone turnover.

Additionally, eating 50 or 100 grams of prunes a day for six months prevented loss of total bone mineral density and decreased TRAP-5b -- a marker of bone resorption -- compared to women who didn't eat prunes.

"Taken together, evidence from in vitro, preclinical studies, and limited clinical studies suggest prunes may help to reduce bone loss," Rogers said. "This may be due to altered bone turnover and by inhibiting inflammation and suppressing markers of oxidative stress."

The researchers said one potential mechanism for the effects is prunes triggering a change in the gut microbiome that then lowers inflammation in the colon. This may then lower levels of pro-inflammatory cytokines and markers of oxidative damage.

In the future, the researchers plan to further report on the effects of prune consumption for 12 months on bone outcomes, inflammatory pathways and the gut microbiota in a randomized controlled trial that was led by De Souza.

Janhavi Damani, graduate student in the Huck Institutes of the Life Sciences; Hannah VanEvery, graduate student in nutritional sciences; and Nicole Strock, postdoctoral scholar in kinesiology, also participated in this work.

The California Dried Plum Board helped support this research.

https://www.sciencedaily.com/releases/2022/02/220209112110.htm

Changing your diet could add up to a decade to life expectancy

A new model, available as an online calculator, estimates the impact of dietary changes on life expectancy

February 8, 2022

Science Daily/PLOS

A young adult in the U.S. could add more than a decade to their life expectancy by changing their diet from a typical Western diet to an optimized diet that includes more legumes, whole grains and nuts, and less red and processed meat, according to a new study publishing Feb. 8 in PLOS Medicine by Lars Fadnes of the University of Bergen, Norway, and colleagues. For older people, the anticipated gains to life expectancy from such dietary changes would be smaller but still substantial.

Food is fundamental for health and, globally, dietary risk factors are estimated to lead to 11 million deaths and 255 million disability-adjusted life-years annually. In the new study, researchers used existing meta-analyses and data from the Global Burden of Diseases study to build a model that enables the instant estimation of the effect on life expectancy (LE) of a range of dietary changes. The model is also now available as a publicly available online tool called the Food4HealthyLife calculator (https://food4healthylife.org/).

For young adults in the United States, the model estimates that a sustained change from a typical Western diet to the optimal diet beginning at age 20 would increase LE by more than a decade for women (10.7 [uncertainty interval 5.9-14.1] years) and men (13.0 [6.9-17.3] years). The largest gains in years of LE would be made by eating more legumes (females: 2.2 [1.0-3.4]; males: 2.5 [1.1-3.9]), more whole grains (females: 2.0 [0.7-3.3]; males: 2.3 [0.8-3.8]), and more nuts (females: 1.7 [0.8-2.7]; males: 2.0 [1.0-3.0]), less red meat (females: 1.6 [0.7-2.5]; males: 1.9 [0.8-3.0]) and less processed meat (females: 1.6 [0.7-2.5]; males: 1.9 [0.8-3.0]). Changing from a typical diet to the optimized diet at age 60 years could still increase LE by 8.0 (4.8-11.2) years for women and 8.8 (5.2-12.5) years for men, and 80-year-olds could gain 3.4 years (females: 2.1-4.7 and males: 2.1-4.8) from such dietary changes.

"Understanding the relative health potential of different food groups could enable people to make feasible and significant health gains," the authors say. "The Food4HealthyLife calculator could be a useful tool for clinicians, policy makers, and lay-people to understand the health impact of dietary choices."

Fadnes adds, "Research until now have shown health benefits associated with separate food group or specific diet patterns but given limited information on the health impact of other diet changes. Our modeling methodology has bridged this gap."

https://www.sciencedaily.com/releases/2022/02/220208143307.htm

When it comes to obesity, the problem isn’t an excess of fat but its loss of function

February 3, 2022

Science Daily/Cell Press

Obesity is known to cause cardiometabolic diseases like hypertension and diabetes but attributing these diseases to merely an overabundance of fat is a simplification. On a basic level, fat acts as a receptacle to store energy, but upon a closer look it is an essential actor in vital bodily processes like the immune response, the regulation of insulin sensitivity, and maintenance of body temperature. In a review published in the journal Cell on February 3rd, researchers argue that the negative health effects of obesity stem not simply from an excess of fat but from the decline in its ability to respond to changes, or in other words, its plasticity.

The makeup and functioning of this tissue changes in response to weight fluctuations and aging. As fat declines in plasticity due to aging and obesity, it loses its ability to respond to bodily cues. In the current model of this phenomenon, the rapid growth of adipose tissue outpaces its blood supply, depriving the fat cells of oxygen and causing the accumulation of cells that no longer divide. This leads to insulin resistance, inflammation, and cell death accompanied by the uncontrolled spill of lipids from these cells.

"The central role of adipose tissue dysfunction in disease and the incredible plasticity of fat tissue supports the promise of modulating fat tissue phenotypes for therapeutic purposes," write the authors, led by Claudio J. Villanueva (@ClaudioVillanu) from the College of Life Sciences/David Geffen School of Medicine and Patrick Seale (@LabSeale) from Perelman School of Medicine at the University of Pennsylvania. "Many questions and opportunities for future discovery remain, which will yield new insights into adipose tissue biology and hopefully lead to improved therapies for human disease."

https://www.sciencedaily.com/releases/2022/02/220203122923.htm

More spice could help seniors avoid salt

February 3, 2022

Science Daily/Washington State University

Add a little spicy seasoning to a low sodium meal, and adults over the age of 60 may have a harder time noticing a lack of salt, according to a new study in the journal Food Quality and Preference.

Led by Carolyn Ross, a professor of Food Sciences at Washington State University, the study tested saltiness perception in older adults using white sauce formulations with varying amounts of salt and different spices and seasonings added.

The results of the analysis showed the addition of chipotle seasoning to the white sauce made it difficult for the study participants to differentiate between the samples with low and high levels of salt. Conversely, the addition of herbs, such as basil leaves, garlic powder and coarse ground pepper, was not as effective at masking the samples with less salt. The research points to the significant role that spice could play in reducing salt intake for people over 60.

"We were working specifically with a population of older adults to see if we could reduce the amount of salt in a product and then tailor it to their tastes," Ross said. "This is important because the ability to taste and smell is known to weaken with age, and weaker perception of salty flavors may induce people to season their food with excessive salt, which may increase their risk of cardiovascular disease."

For their study, Ross and María Laura Montero, a postdoctoral researcher in the WSU School of Food Sciences, recruited 39 healthy people over the age of 60 to participate in an in-person taste testing experiment that took place over several days slightly prior to the onset of the COVID-19 pandemic.

Previous research examining saltiness perception in older adults has tended to use water as a matrix for tasting experiments rather than actual food products. To generate more realistic data in terms of what people actually enjoy eating, Ross and Montero used a white sauce formulation that is commonly found in ready-to-eat Cajun chicken pasta meals.

The study participants were asked to compare three different formulations of the sauce at five different salt concentrations. One of the formulations had no added herbs, the second had just herbs, and the third had both herbs and chipotle seasoning. Their results showed the formulation with both herbs and chipotle seasoning made it difficult for the seniors to determine the amount of salt being used while the formulation with exclusively herbs did not.

In addition to administering the taste test, the researchers surveyed their participants about their oral and olfactory health, the number and type of medications they were taking and any other pre-existing conditions that might affect their saltiness perception.

Their analysis showed there was a positive correlation between poor oral health and the number of medications each participant was taking, which could be a result of less saliva production; however, their data on whether or not this was the main cause of lowered saltiness perception wasn't conclusive.

Moving forward, when it is once again feasible to recruit participants for in-person studies, the researchers plan to follow-up with a larger study evaluating lower salt concentrations as well as different herb and spice concentrations.

"To date, a clear relationship between taste loss, and thus higher taste thresholds, and eating behavior remains to be established," Ross said. "So, we are investigating a bunch of different possible factors."

https://www.sciencedaily.com/releases/2022/02/220203083613.htm

Greater body fat a risk factor for reduced thinking and memory ability

February 1, 2022

Science Daily/McMaster University

A new study has found that greater body fat is a risk factor for reduced cognitive function, such as processing speed, in adults.

Even when the researchers took cardiovascular risk factors (such as diabetes or high blood pressure) or vascular brain injury into account, the association between body fat and lower cognitive scores remained. This suggests other not yet confirmed pathways that linked excess body fat to reduced cognitive function.

In the study, 9,166 participants were measured by bioelectrical impedance analysis to assess their total body fat.

As well, 6,733 of the participants underwent magnetic resonance imaging (MRI) to measure abdominal fat packed around the organs known as visceral fat, and the MRI also assessed vascular brain injury -- areas in the brain affected by reduced blood flow to the brain.

The results were published today in JAMA Network Open.

"Our results suggest that strategies to prevent or reduce having too much body fat may preserve cognitive function," said lead author Sonia Anand, a professor of medicine of McMaster University's Michael G. DeGroote School of Medicine and a vascular medicine specialist at Hamilton Health Sciences (HHS). She is also a senior scientist of the Population Health Research Institute of McMaster and HHS.

She added that "the effect of increased body fat persisted even after adjusting for its effect on increasing cardiovascular risk factors like diabetes and high blood pressure, as well as vascular brain injury, which should prompt researchers to investigate which other pathways may link excess fat to reduced cognitive function."

Co-author Eric Smith, a neurologist, scientist and an associate professor of clinical neurosciences at the University of Calgary, said that "preserving cognitive function is one of the best ways to prevent dementia in old age. This study suggests that one of the ways that good nutrition and physical activity prevent dementia may be by maintaining healthy weight and body fat percentage."

Smith is head of the brain core lab for the two population cohorts used for this new analysis- the Canadian Alliance for Healthy Hearts and Minds (CAHHM) and PURE Mind- a sub-study of the large, international Prospective Urban Rural Epidemiological (PURE) study.

The participants were in the age range of 30 to 75 with an average age of about 58. Just over 56% were women; they all lived in either Canada or Poland. The majority were White European origin, with about 16% other ethnic backgrounds. Individuals with known cardiovascular disease were excluded.

https://www.sciencedaily.com/releases/2022/02/220201144019.htm

Green-med diet seems to slow age-related neurodegeneration

January 13, 2022

Science Daily/Ben-Gurion University of the Negev

A green Mediterranean diet, high in polyphenols and low in red and processed meat, seems to slow age-related brain atrophy, according to a new Ben-Gurion University of the Negev-led international study. The DIRECT PLUS 18-month long randomized control trial among approximately 300 participants is one of the longest and largest brain MRI trials in the world.

Their findings were published Tuesday in The American Journal of Clinical Nutrition.

The effect of diet on age-related brain atrophy is largely unproven. Participants were divided into three groups according to diet, and whole brain MRI measurements were taken before, and after the trial. Hippocampal-occupancy (HOC) and lateral-ventricle-volume (LVV) were measured as indicators of brain atrophy and predictors of future dementia. Brain MRI-derived data were quantified and segmented using NeuroQuant, an FDA (Food and Drug Administration) authorized fully automated tool.

Two hundred eighty-four men and women (88% men) aged 31-82 were randomly divided into three groups: A healthy dietary guidelines group, a Mediterranean diet group and a green Mediterranean diet. In the Mediterranean diet group, the participants were further provided walnuts rich in polyphenols. In the green- Mediterranean group the participants were further provided high polyphenol green components: 3-4 daily cups of green tea and a daily green shake of Mankai duckweed, as a substitute for dinner, with minimal consumption of red and processed meat. In addition, all three groups participated in physical activity programs based on aerobic exercise, including free gym memberships.

The trial was performed by Dr. Alon Kaplan and Prof. Iris Shai, professor at Ben-Gurion University, Israel, and adjunct professor at Harvard University, together with several international teams of brain experts. The researchers were surprised to identify dramatic changes in MRI-related brain atrophy within 18-24 months, whereas the rate of brain atrophy markers (i.e., hippocampal occupancy decline and lateral ventricle volume expansion) were significantly accelerated from the age of 50 years and up.

The researchers discovered a significant attenuation in brain atrophy over the 18 months in those who adhered to both Mediterranean diets; with greater magnitude in the green-MED group, specifically among participants over age 50. In addition, the researchers noticed that an improvement in insulin sensitivity was independently associated with attenuated brain atrophy.

Greater Mankai, green tea, and walnuts consumption and less red and processed meat consumption were significantly associated with lower hippocampal occupancy decline.

Participants were initially chosen based on abdominal girth size or dyslipidemia. They were all employees at a remote workplace in Israel (Nuclear Research Center in Dimona) where they did not leave the premises during the workday, and the lunch provided was monitored.

"The beneficial association between the green Mediterranean diet and age-related neurodegeneration might be partially explained by the abundance of polyphenols in plant-based food sources which have antioxidant and anti-inflammatory metabolites. Polyphenols can cross the blood-brain barrier (BBB), reduce neuroinflammation, and induce cell proliferation and adult-onset neurogenesis in the hippocampus," writes Prof. Shai, the lead author.

"Our findings might suggest a simple, safe, and promising avenue to slow age-related neurodegeneration by adhering to a green-Mediterranean diet," adds Dr. Alon Kaplan.

https://www.sciencedaily.com/releases/2022/01/220113111508.htm

Fasting is required to see the full benefit of calorie restriction in mice

October 18, 2021

Science Daily/University of Wisconsin-Madison

Over the last few decades, scientists have discovered that long-term calorie restriction provides a wealth of benefits in animals: lower weight, better blood sugar control, even longer lifespans.

Researchers have largely assumed that reduced food intake drove these benefits by reprogramming metabolism. But a new study from University of Wisconsin-Madison researchers finds that reduced calorie intake alone is not enough; fasting is essential for mice to derive full benefit.

The new findings lend support to preliminary evidence that fasting can boost health in people, as trends like intermittent fasting continue to hold sway. These human and animal studies have added to the growing picture of how health is controlled by when and what we eat, not just how much.

The research further emphasizes the complexity of nutrition and metabolism and provides guidance to researchers trying to untangle the true causes of diet-induced health benefits in animals and humans.

The researchers discovered that, combined with eating less, fasting reduces frailty in old age and extends the lifespan of mice. And fasting alone can improve blood sugar and liver metabolism.

Surprisingly, mice that ate fewer calories but never fasted died younger than mice that ate as much as they wanted, suggesting that calorie restriction alone may be harmful.

The research was led by UW School of Medicine and Public Health metabolism researcher Dudley Lamming, his graduate student Heidi Pak and their colleagues at UW-Madison and other institutions. The team published their findings Oct. 18 in Nature Metabolism.

Pak and Lamming were inspired to conduct the study because researchers began to realize that previous studies had unintentionally combined calorie restrictions with long fasts by providing animals with food just once a day. It was difficult, then, to distinguish the effects of one from the other.

"This overlap of treatment -- both reducing calories and imposing a fast -- was something that everybody saw, but it wasn't always obvious that it had biological significance," says Lamming, who has long studied the effect of restricted diets on metabolism. "It's only been in the past few years that people started getting interested in this issue."

To untangle these factors, Lamming's group designed four different diets for mice to follow. One group ate as much as they wanted whenever they wanted. Another group ate a full amount, but in a short period of time -- this gave them a long daily fast without reducing calories.

The other two groups were given about 30% fewer calories either once a day or dispersed over the entire day. That meant that some mice had a long daily fast while others ate the same reduced-calorie diet but never fasted, which differed from most previous studies of calorie restriction.

It turned out that many of the benefits originally ascribed to calorie restriction alone -- better blood sugar control, healthier use of fat for energy, protection from frailty in old age and longer lifespans -- all required fasting as well. Mice who ate fewer calories without fasting didn't see these positive changes.

Fasting on its own, without reducing the amount of food eaten, was just as powerful as calorie restriction with fasting. Fasting alone was enough to improve insulin sensitivity and to reprogram metabolism to focus more on using fats as a source of energy. The livers of fasting mice also showed the hallmarks of healthier metabolism.

The researchers did not study the effect of fasting alone on lifespan or frailty as mice aged, but other studies have suggested that fasting can provide these benefits as well.

While the mice that ate fewer calories without ever fasting did show some improved blood sugar control, they also died younger. Compared with mice who both ate less and fasted, these mice that only ate less died about 8 months earlier on average.

"That was quite surprising," says Lamming, although other studies have also shown some negative effects from restricting calories. The team also measured frailty through metrics like grip strength and coat condition. "In addition to their shorter lifespans, these mice were worse in certain aspects of frailty, but better in others. So, on balance their frailty didn't change much, but they didn't look as healthy."

The primary studies were done in male mice, but Lamming's lab also found similar metabolic effects of fasting in female mice.

The research reveals how difficult diet studies are, even in a laboratory environment. That difficulty is magnified for human studies, which simply can't match the level of control possible in animal models. The new study can provide direction to future work trying to answer whether fasting improves human health.

"We need to know whether this fasting is required for people to see benefits," Lamming says. "If fasting is the main driver of health, we should be studying drugs or diet interventions that mimic fasting rather than those that mimic fewer calories."

https://www.sciencedaily.com/releases/2021/10/211018112513.htm

MIND diet linked to better cognitive performance

Study finds diet may contribute to cognitive resilience in the elderly

September 21, 2021

Science Daily/Rush University Medical Center

Aging takes a toll on the body and on the mind. For example, the tissue of aging human brains sometimes develops abnormal clumps of proteins that are the hallmark of Alzheimer's disease. How can you protect your brain from these effects?

Researchers at Rush University Medical Center have found that older adults may benefit from a specific diet called the MIND diet even when they develop these protein deposits, known as amyloid plaques and tangles. Plaques and tangles are a pathology found in the brain that build up in between nerve cells and typically interfere with thinking and problem-solving skills.

Developed by the late Martha Clare Morris, ScD, who was a Rush nutritional epidemiologist, and her colleagues, the MIND diet is a hybrid of the Mediterranean and DASH (Dietary Approaches to Stop Hypertension) diets. Previous research studies have found that the MIND diet may reduce a person's risk of developing Alzheimer's disease dementia.

Now a study has shown that participants in the study who followed the MIND diet moderately later in life did not have cognition problems, according to a paper published on Sept. 14 in the Journal of Alzheimer's Disease.

"Some people have enough plaques and tangles in their brains to have a postmortem diagnosis of Alzheimer's disease, but they do not develop clinical dementia in their lifetime," said Klodian Dhana, MD, PhD, lead author of the paper and an assistant professor in the Division of Geriatrics and Palliative Medicine in the Department of Internal Medicine at Rush Medical College .

"Some have the ability to maintain cognitive function despite the accumulation of these pathologies in the brain, and our study suggests that the MIND diet is associated with better cognitive functions independently of brain pathologies related to Alzheimer's disease.

In this study, the researchers examined the associations of diet -- from the start of the study until death -- brain pathologies and cognitive functioning in older adults who participated in the Rush Alzheimer's Disease Center's ongoing Memory and Aging Project, which began in 1997 and includes people living in greater Chicago. The participants were mostly white without known dementia, and all of them agreed to undergo annual clinical evaluations while alive and brain autopsy after their death.

The researchers followed 569 participants, who were asked to complete annual evaluations and cognitive tests to see if they had developed memory and thinking problems. Beginning in 2004, participants were given an annual food frequency questionnaire about how often they ate 144 food items in previous year.

Using the questionnaire answers, the researchers gave each participant a MIND diet score based on how often the participants ate specific foods. The MIND diet has 15 dietary components, including 10 "brain-healthy food groups" and five unhealthy groups -- red meat, butter and stick margarine, cheese, pastries and sweets, and fried or fast food.

To adhere to and benefit from the MIND diet, a person would need to eat at least three servings of whole grains, a green leafy vegetable and one other vegetable every day -- along with a glass of wine -- snack most days on nuts, have beans every other day or so, eat poultry and berries at least twice a week and fish at least once a week. A person also must limit intake of the designated unhealthy foods, limiting butter to less than 1 1/2 teaspoons a day and eating less than a serving a week of sweets and pastries, whole fat cheese, and fried or fast food.

Based on the frequency of intake reported for the healthy and unhealthy food groups, the researchers calculated the MIND diet score for each participant across the study period. An average of the MIND diet score from the start of the study until the participant's death was used in the analysis to limit measurement error. Seven sensitivity measures were calculated to confirm accuracy of the findings.

"We found that a higher MIND diet score was associated with better memory and thinking skills independently of Alzheimer's disease pathology and other common age-related brain pathologies. The diet seemed to have a protective capacity and may contribute to cognitive resilience in the elderly." Dhana said.

"Diet changes can impact cognitive functioning and risk of dementia, for better or worse," he continued. "There are fairly simple diet and lifestyle changes a person could make that may help to slow cognitive decline with aging, and contribute to brain health."

https://www.sciencedaily.com/releases/2021/09/210921172721.htm

Healthy changes in diet, activity improved treatment-resistant high blood pressure

September 27, 2021

Science Daily/American Heart Association

People with treatment-resistant hypertension successfully reduced their blood pressure by adopting the Dietary Approaches to Stop Hypertension (DASH) eating plan, losing weight and improving their aerobic fitness by participating in a structured diet and exercise program at a certified cardiac rehabilitation facility, according to new research published today in the American Heart Association's flagship journal Circulation.

Uncontrolled high blood pressure (130/80 mm Hg or higher) despite the use of three or more medications of different classes including a diuretic to reduce blood pressure is a condition known as resistant hypertension. Although estimates vary, resistant hypertension likely affects about 5% of the general global population and may affect 20% to 30% of adults with high blood pressure. Resistant hypertension is also associated with end-organ damage and a 50% greater risk of adverse cardiovascular events, including stroke, heart attack and death.

Diet and exercise are well-established treatments for high blood pressure. In June 2021, the American Heart Association advised that physical activity is the optimal first treatment choice for adults with mild to moderately elevated blood pressure and blood cholesterol who otherwise have low heart disease risk.

This new study, Treating Resistant Hypertension Using Lifestyle Modification to Promote Health (TRIUMPH), is the first to evaluate the impact of lifestyle modifications in people with resistant hypertension. Researchers found that behavioral changes, including regular aerobic exercise, adoption of the DASH (Dietary Approaches to Stop Hypertension) diet, reducing salt consumption and losing weight, can lower blood pressure significantly and improve cardiovascular health in people with resistant hypertension. The DASH eating plan is rich in fruits, vegetables, low-fat dairy products and limited salt, and aligns with the American Heart Association's nutrition recommendations.

The four-month clinical trial involved 140 adults with resistant hypertension (average age 63; 48% women; 59% Black adults; 31% with type 2 diabetes; and 21% with chronic kidney disease). Participants were randomly divided into two groups -- 90 participants received weekly dietary counseling and exercise training in an intensive, supervised cardiac rehabilitation setting three times a week. The other 50 participants received a single informational session from a health educator and written guidelines on exercise, weight loss and nutritional goals to follow on their own.

Researchers found:

• The participants in the supervised program had about a 12-point drop in systolic blood pressure, compared to 7 points in the self-guided group. Systolic blood pressure (the first number in a blood pressure reading) indicates how much pressure blood is exerting against artery walls when the heart beats and is recognized as a major risk factor for cardiovascular disease for adults ages 50 and older.

• Blood pressure measures captured through 24 hours of ambulatory monitoring during a typical day revealed that the group in the supervised lifestyle program had a 7-point reduction in systolic blood pressure, while the self-guided group had no change in blood pressure.

• Participants in the supervised program also had greater improvements in other key indicators of heart health, suggesting that they had a lower risk of a heart event in the future.

"Our findings showed lifestyle modifications among people with resistant hypertension can help them successfully lose weight and increase their physical activity, and as a result, lower blood pressure and potentially reduce their risk of heart attack or stroke," said James A. Blumenthal, Ph.D., first and senior author of the study, and J.P. Gibbons Professor of Psychiatry and Behavioral Sciences at Duke University School of Medicine in Durham, North Carolina. "While some people can make lifestyle changes on their own, a structured program of supervised exercise and dietary modifications conducted by a multidisciplinary team of health care professionals in cardiac rehabilitation programs is likely more effective."

Blumenthal noted that the success of the supervised program doesn't mean people with resistant hypertension can stop taking their medications; however, it suggests that they may want to talk with their physicians about possibly reducing the dosages or altering their medications based upon their lowered blood pressure values.

The study was conducted at a single institution -- Duke University School of Medicine -- so findings may not be generalizable to broader groups of people. However, the intensive, structured, supervised part of the study occurred at several representative cardiac rehabilitation centers in central North Carolina, with educational and cultural diversity well represented. Researchers believe the program could be implemented with success at similar cardiac rehabilitation centers throughout the county. Also, the study's impact beyond the four months of monitoring is limited by whether participants who made significant lifestyle changes will maintain them. "The benefits of the lifestyle modifications may be reduced unless the healthy lifestyle habits can be maintained," Blumenthal said.

"The most important point is that it is not too late to lower blood pressure by making healthy lifestyle choices," he said. "Adopting a healthy lifestyle pays huge dividends, even for people whose blood pressure remains elevated despite being on three or more antihypertensive medications."

American Heart Association volunteer expert Bethany Barone Gibbs, Ph.D., FAHA, noted that this data gives clinicians another evidence-based tool for helping patients with resistant hypertension.

"Though we usually think about recommending lifestyle changes like losing weight and getting more physical activity before starting medications, this study provides important reinforcement that adding lifestyle changes in conjunction with medications -- and when medications alone are not doing the job -- is an effective strategy," said Gibbs, an associate professor in the department of health and human development and clinical and translational sciences at the University of Pittsburgh. "Also exciting is that Blumenthal, et. al., used a cardiac rehab model, which can be duplicated in many settings."

Gibbs, chair of the statement writing group of the Association's June 2021 scientific statement on lifestyle treatment for hypertension, urged patients to commit to lifestyle changes -- losing 5% to 10% of their bodyweight, greater adherence to the DASH-style diet, and increasing steps by at least 1,000 per day can yield health benefits.

https://www.sciencedaily.com/releases/2021/09/210927092147.htm

Strength training can burn fat too, myth-busting study finds

September 22, 2021

Science Daily/University of New South Wales

It's basic exercise knowledge that to gain muscles, you strength train, and to lose fat, you do cardio -- right?

Not necessarily, a new UNSW study published this week in Sports Medicine suggests.

In fact, the study -- a systematic review and meta-analysis that reviewed and analysed existing evidence -- shows we can lose around 1.4 per cent of our entire body fat through strength training alone, which is similar to how much we might lose through cardio or aerobics.

"A lot of people think that if you want to lose weight, you need to go out and run," says senior author of the study Dr Mandy Hagstrom, exercise physiologist and senior lecturer at UNSW Medicine & Health.

"But our findings show that even when strength training is done on its own, it still causes a favourable loss of body fat without having to consciously diet or go running."

Up until now, the link between strength training and fat loss has been unclear. Studies have investigated this link in the past, but their sample sizes tend to be small -- a side effect of not many people wanting to volunteer to exercise for months on end. Smaller sample sizes can make it difficult to find statistically significant results, especially as many bodies can respond differently to exercise programs.

"It can be really difficult to discern whether there's an effect or not based on one study alone," says Dr Hagstrom. "But when we add all of these studies together, we effectively create one large study, and can get a much clearer idea of what's going on."

Dr Hagstrom and her team pulled together the findings from 58 research papers that used highly accurate forms of body fat measurement (like body scans, which can differentiate fat mass from lean mass) to measure the outcomes from strength training programs. Altogether, the studies included 3000 participants, none of which had any previous weight training experience.

While the strength training programs differed between the studies, the participants worked out for roughly 45-60 minutes each session for an average of 2.7 times per week. The programs lasted for about five months.

The team found that, on average, the participants lost 1.4 per cent of their total body fat after their training programs, which equated to roughly half a kilo in fat mass for most participants.

While the findings are encouraging for fans of pumping iron, Dr Hagstrom says the best approach for people who are aiming to lose fat is still to stick to eating nutritiously and having an exercise routine that includes both aerobic/cardio and strength training.

But if aerobics and cardio just aren't your thing, the good news is you don't need to force it.

"If you want to exercise to change your body composition, you've got options," says Dr Hagstrom.

"Do what exercise you want to do and what you're most likely to stick to."

Busting the fat loss myth

Part of the reason many people think strength training doesn't live up to cardio in terms of fat loss comes down to inaccurate ways of measuring fat.

For example, many people focus on the number they see on the scale -- that is, their total body weight. But this figure doesn't differentiate fat mass from everything else that makes up the body, like water, bones and muscles.

"More often than not, we don't gain any muscle mass when we do aerobic training," says Dr Hagstrom. "We improve our cardiorespiratory fitness, gain other health and functional benefits, and can lose body fat.

"But when we strength train, we gain muscle mass and lose body fat, so the number on the scales won't look as low as it would after aerobics training, especially as muscle weighs more than fat."

The research team focused on measuring how much the total body fat percentage -- that is, the amount of your body that's made up of fat mass -- changed after strength training programs. This measurement showed fat loss appears to be on par with aerobics and cardio training, despite the different figures on the scales.

"A lot of fitness recommendations come from studies that use inaccurate measurement tools, like bioelectrical impedance or scales," says Dr Hagstrom.

"But the most accurate and reliable way of assessing body fat is through DEXA, MRI or CT scans. They can compartmentalise the body and separate fat mass from lean tissue."

While this study didn't show whether variables like exercise duration, frequency, intensity, or set volume impacted fat loss percentage, the team hope to next investigate whether how we strength train can change the amount of fat loss.

A better way of measuring progress

As part of their study, the team conducted a sub-analysis comparing how different ways of measuring fat can influence a study's findings.

Interestingly, it showed that when papers used more accurate measurements like body scans, they tended to show lower overall changes in body fat.

"Using accurate fat measurements is important because it gives us a more realistic idea of what body changes to expect," says lead author of the study Mr Michael Wewege, PhD candidate at UNSW and NeuRA.

"Future exercise studies can improve their research by using these more accurate body measurements."

Reframing the way we measure progress doesn't just apply to sports researchers, but to everyday people, too.

"Resistance training does so many fantastic things to the body that other forms of exercise don't, like improving bone mineral density, lean mass and muscle quality. Now, we know it also gives you a benefit we previously thought only came from aerobics," says Dr Hagstrom.

"If you're strength training and want to change how your body looks, then you don't want to focus on the number on the scale too much, because it won't show you all your results.

"Instead, think about your whole body composition, like how your clothes fit and how your body will start to feel, and move, differently."

https://www.sciencedaily.com/releases/2021/09/210922121905.htm

Sticking to low-fat dairy may not be the only heart healthy option

September 21, 2021

Science Daily/George Institute for Global Health

New research amongst the world's biggest consumers of dairy foods has shown that those with higher intakes of dairy fat -- measured by levels of fatty acids in the blood -- had a lower risk of cardiovascular disease compared to those with low intakes. Higher intakes of dairy fat were not associated with an increased risk of death.

Researchers then combined the results of this study in just over 4,000 Swedish adults with those from 17 similar studies in other countries, creating the most comprehensive evidence to date on the relationship between this more objective measure of dairy fat consumption, risk of cardiovascular disease (CVD) and death.

Dr Matti Marklund from The George Institute for Global Health, Johns Hopkins Bloomberg School of Public Health, and Uppsala University said that with dairy consumption on the rise worldwide, a better understanding of the health impact was needed.

"Many studies have relied on people being able to remember and record the amounts and types of dairy foods they've eaten, which is especially difficult given that dairy is commonly used in a variety of foods.

"Instead, we measured blood levels of certain fatty acids, or fat 'building blocks' that are found in dairy foods, which gives a more objective measure of dairy fat intake that doesn't rely on memory or the quality of food databases," he added.

"We found those with the highest levels actually had the lowest risk of CVD. These relationships are highly interesting, but we need further studies to better understand the full health impact of dairy fats and dairy foods."

Dairy and dairy product consumption in Sweden is among the highest worldwide. An international collaboration between researchers in Sweden, the US and Australia assessed dairy fat consumption in 4150 Swedish 60-year-olds by measuring blood levels of a particular fatty acid that is mainly found in dairy foods and therefore can be used to reflect intake of dairy fat.

They were then followed up for an average of 16 years to see how many had heart attacks, strokes and other serious circulatory events, and how many died from any cause during this time.

After statistically adjusting for other known CVD risk factors including things like age, income, lifestyle, dietary habits, and other diseases, the CVD risk was lowest for those with high levels of the fatty acid (reflecting high intake of dairy fats). Those with the highest levels had no increased risk of death from all causes.

Dr Marklund added that the findings highlight the uncertainty of evidence in this area, which is reflected in dietary guidelines.

"While some dietary guidelines continue to suggest consumers choose low-fat dairy products, others have moved away from that advice, instead suggesting dairy can be part of a healthy diet with an emphasis on selecting certain dairy foods -- for example, yoghurt rather than butter -- or avoiding sweetened dairy products that are loaded with added sugar," he said.

Combining these results with 17 other studies involving a total of almost 43,000 people from the US, Denmark, and the UK confirmed these findings in other populations.

"While the findings may be partly influenced by factors other than dairy fat, our study does not suggest any harm of dairy fat per se," Dr Marklund said.

Lead author Dr Kathy Trieu from The George Institute for Global Health said that consumption of some dairy foods, especially fermented products, have previously been associated with benefits for the heart.

"Increasing evidence suggests that the health impact of dairy foods may be more dependent on the type -- such as cheese, yoghurt, milk, and butter -- rather than the fat content, which has raised doubts if avoidance of dairy fats overall is beneficial for cardiovascular health," she said.

"Our study suggests that cutting down on dairy fat or avoiding dairy altogether might not be the best choice for heart health."

"It is important to remember that although dairy foods can be rich in saturated fat, they are also rich in many other nutrients and can be a part of a healthy diet. However, other fats like those found in seafood, nuts, and non-tropical vegetable oils can have greater health benefits than dairy fats," Dr Trieu added.

https://www.sciencedaily.com/releases/2021/09/210921140119.htm

Gut microbiota influences the ability to lose weight

September 14, 2021

Science Daily/American Society for Microbiology

Gut microbiota influences the ability to lose weight in humans, according to new research. The findings were published this week in mSystems, an open-access journal of the American Society for Microbiology.

"Your gut microbiome can help or cause resistance to weight loss and this opens up the possibility to try to alter the gut microbiome to impact weight loss," said lead study author Christian Diener, Ph.D., a research scientist at the Institute for Systems Biology in Seattle, Washington.

To conduct their research, Dr. Diener and colleagues focused on a large cohort of individuals who were involved in a lifestyle intervention study. Instead of a specific diet or exercise program, this intervention involved a commercial behavioral coaching program paired with advice from a dietician and nurse coach. The researchers focused on 48 individuals who lost more than 1% of their body weight per month over a 6 to 12 month period and 57 individuals who did not lose any weight and had a stable body mass index (BMI) over the same period. The researchers relied on metagenomics, the study of genetic material recovered from blood and stool samples. The individuals analyzed blood metabolites, blood proteins, clinical labs, dietary questionnaires and gut bacteria in the two groups.

After controlling for age, sex and baseline BMI, the researchers identified 31 baseline stool metagenomic functional features that were associated with weight loss responses. These included complex polysaccharide and protein degradation genes, stress-response genes, respiration-related genes, cell wall synthesis genes and gut bacterial replication rates. A major finding was that the ability of the gut microbiome to break down starches was increased in people who did not lose weight. Another key finding was that genes that help bacteria grow faster, multiply, replicate and assemble cell walls were increased in people who lost more weight.

"Before this study, we knew the composition of bacteria in the gut were different in obese people than in people who were non-obese, but now we have seen that there are a different set of genes that are encoded in the bacteria in our gut that also responds to weight loss interventions," said Dr. Diener. "The gut microbiome is a major player in modulating whether a weight loss intervention will have success or not. The factors that dictate obesity versus nonobesity are not the same factors that dictate whether you will lose weight on a lifestyle intervention."

Research has already shown that if you change your diet, you can alter the composition of bacteria in your gut. According to Dr. Diener, if someone has a composition of gut bacterial genes that confers resistance to weight loss, then perhaps you can alter their diet to shift to a composition that would help them lose weight.

https://www.sciencedaily.com/releases/2021/09/210914135522.htm

Scientists claim that overeating is not the primary cause of obesity

September 13, 2021

Science Daily/American Society for Nutrition

Statistics from the Centers for Disease Control and Prevention (CDC) show that obesity affects more than 40% of American adults, placing them at higher risk for heart disease, stroke, type 2 diabetes, and certain types of cancer. The USDA's Dietary Guidelines for Americans 2020 -- 2025 further tells us that losing weight "requires adults to reduce the number of calories they get from foods and beverages and increase the amount expended through physical activity."

This approach to weight management is based on the century-old energy balance model which states that weight gain is caused by consuming more energy than we expend. In today's world, surrounded by highly palatable, heavily marketed, cheap processed foods, it's easy for people to eat more calories than they need, an imbalance that is further exacerbated by today's sedentary lifestyles. By this thinking, overeating, coupled with insufficient physical activity, is driving the obesity epidemic. On the other hand, despite decades of public health messaging exhorting people to eat less and exercise more, rates of obesity and obesity-related diseases have steadily risen.

The authors of "The Carbohydrate-Insulin Model: A Physiological Perspective on the Obesity Pandemic," a perspective published in The American Journal of Clinical Nutrition, point to fundamental flaws in the energy balance model, arguing that an alternate model, the carbohydrate-insulin model, better explains obesity and weight gain. Moreover, the carbohydrate-insulin model points the way to more effective, long-lasting weight management strategies.

According to lead author Dr. David Ludwig, Endocrinologist at Boston Children's Hospital and Professor at Harvard Medical School, the energy balance model doesn't help us understand the biological causes of weight gain: "During a growth spurt, for instance, adolescents may increase food intake by 1,000 calories a day. But does their overeating cause the growth spurt or does the growth spurt cause the adolescent to get hungry and overeat?"

In contrast to the energy balance model, the carbohydrate-insulin model makes a bold claim: overeating isn't the main cause of obesity. Instead, the carbohydrate-insulin model lays much of the blame for the current obesity epidemic on modern dietary patterns characterized by excessive consumption of foods with a high glycemic load: in particular, processed, rapidly digestible carbohydrates. These foods cause hormonal responses that fundamentally change our metabolism, driving fat storage, weight gain, and obesity.

When we eat highly processed carbohydrates, the body increases insulin secretion and suppresses glucagon secretion. This, in turn, signals fat cells to store more calories, leaving fewer calories available to fuel muscles and other metabolically active tissues. The brain perceives that the body isn't getting enough energy, which, in turn, leads to feelings of hunger. In addition, metabolism may slow down in the body's attempt to conserve fuel. Thus, we tend to remain hungry, even as we continue to gain excess fat.

To understand the obesity epidemic, we need to consider not only how much we're eating, but also how the foods we eat affect our hormones and metabolism. With its assertion that all calories are alike to the body, the energy balance model misses this critical piece of the puzzle.

While the carbohydrate-insulin model is not new -- its origins date to the early 1900s -- The American Journal of Clinical Nutritionperspective is the most comprehensive formulation of this model to date, authored by a team of 17 internationally recognized scientists, clinical researchers, and public health experts. Collectively, they have summarized the growing body of evidence in support of the carbohydrate-insulin model. Moreover, the authors have identified a series of testable hypotheses that distinguish the two models to guide future research.

Adoption of the carbohydrate-insulin model over the energy-balance model has radical implications for weight management and obesity treatment. Rather than urge people to eat less, a strategy which usually doesn't work in the long run, the carbohydrate-insulin model suggests another path that focuses more on what we eat. According to Dr. Ludwig, "reducing consumption of the rapidly digestible carbohydrates that flooded the food supply during the low-fat diet era lessens the underlying drive to store body fat. As a result, people may lose weight with less hunger and struggle."

The authors acknowledge that further research is needed to conclusively test both models and, perhaps, to generate new models that better fit the evidence. Toward this end, they call for constructive discourse and "collaborations among scientists with diverse viewpoints to test predictions in rigorous and unbiased research."

https://www.sciencedaily.com/releases/2021/09/210913135729.htm

Eating walnuts daily lowered 'bad' cholesterol and may reduce cardiovascular disease risk

August 30, 2021

Science Daily/American Heart Association

Healthy older adults who ate a handful of walnuts (about ½ cup) a day for two years modestly lowered their level of low-density lipoprotein or LDL cholesterol levels. Consuming walnuts daily also reduced the number of LDL particles, a predictor of cardiovascular disease risk. The study explored the effects of a walnut-enriched diet on overall cholesterol in elderly individuals from diverse geographical locations and spanning two years.

Eating about ½ cup of walnuts every day for two years modestly lowered levels of low-density lipoprotein (LDL) cholesterol, known as "bad cholesterol," and reduced the number of total LDL particles and small LDL particles in healthy, older adults, according to new research published today in the American Heart Association's flagship journal Circulation.

Healthy older adults who ate a handful of walnuts (about ½ cup) a day for two years modestly lowered their level of low-density lipoprotein or LDL cholesterol levels. Consuming walnuts daily also reduced the number of LDL particles, a predictor of cardiovascular disease risk.

Walnuts are a rich source of omega-3 fatty acids (alpha-linolenic acid), which have been shown to have a beneficial effect on cardiovascular health.

"Prior studies have shown that nuts in general, and walnuts in particular, are associated with lower rates of heart disease and stroke. One of the reasons is that they lower LDL-cholesterol levels, and now we have another reason: they improve the quality of LDL particles," said study co-author Emilio Ros, M.D., Ph.D., director of the Lipid Clinic at the Endocrinology and Nutrition Service of the Hospital Clínic of Barcelona in Spain. "LDL particles come in various sizes. Research has shown that small, dense LDL particles are more often associated with atherosclerosis, the plaque or fatty deposits that build up in the arteries. Our study goes beyond LDL cholesterol levels to get a complete picture of all of the lipoproteins and the impact of eating walnuts daily on their potential to improve cardiovascular risk."

In a sub-study of the Walnuts and Healthy Aging study, a large, two-year randomized controlled trial examining whether walnuts contribute to healthy aging, researchers evaluated if regular walnut consumption, regardless of a person's diet or where they live, has beneficial effects on lipoproteins.

This study was conducted from May 2012 to May 2016 and involved 708 participants between the ages of 63 and 79 (68% women) who were healthy, independent-living adults residing in Barcelona, Spain, and Loma Linda, California.

Participants were randomly divided into two groups: active intervention and control. Those allocated to the intervention group added about a half cup of walnuts to their usual daily diet, while participants in the control group abstained from eating any walnuts. After two years, participants' cholesterol levels were tested, and the concentration and size of lipoproteins were analyzed by nuclear magnetic resonance spectroscopy. This advanced test enables physicians to more accurately identify lipoprotein features known to relate to the risk of cardiovascular disease.

The two-year study had a 90% retention rate (632 participants completed the study). Complete lipoprotein analyses were available in 628.

Among key findings of all study participants:

• At 2 years, participants in the walnut group had lower LDL cholesterol levels -- by an average of 4.3 mg/dL, and total cholesterol was lowered by an average of 8.5 mg/dL.

• Daily consumption of walnuts reduced the number of total LDL particles by 4.3% and small LDL particles by 6.1%. These changes in LDL particle concentration and composition are associated with a lower risk of cardiovascular disease.

• Intermediate Density Lipoprotein (IDL) cholesterol also decreased. It is known that IDL cholesterol is a precursor to LDL and refers to a density between that of low-density and very-low-density lipoproteins. In the last decade, IDL cholesterol has emerged as a relevant lipid cardiovascular risk factor independent of LDL cholesterol.

• LDL cholesterol changes among the walnut group differed by sex; in men, LDL cholesterol fell by 7.9% and in women by 2.6%.

"While this is not a tremendous decrease in LDL cholesterol, it's important to note that at the start of the study all our participants were quite healthy, free of major non-communicable diseases. However, as expected in an elderly population, close to 50% of participants were being treated for both high blood pressure and hypercholesterolemia. Thanks in part to statin treatment in 32%, the average cholesterol levels of all the people in our study were normal," Ros said. "For individuals with high blood cholesterol levels, the LDL cholesterol reduction after a nut-enriched diet may be much greater."

"Eating a handful of walnuts every day is a simple way to promote cardiovascular health. Many people are worried about unwanted weight gain when they include nuts in their diet," Ros said. "Our study found that the healthy fats in walnuts did not cause participants to gain weight."

The major limitation of this investigation is that both participants and researchers knew who was and was not eating walnuts. However, the study did involve two very different populations with distinct diets. "The outcomes were similar in both groups, so we can safely apply the results of this study to other populations," Ros said. More research is also needed to clarify the different LDL results in men and women.

According to the American Heart Association, walnuts are especially high in omega-3 fatty acids, the same heart-healthy fat found in oily fish. A serving size is a small handful or 1.5 ounces of whole nuts or 2 tablespoons of nut butter.

The study was funded by the California Walnut Commission.

https://www.sciencedaily.com/releases/2021/08/210830081805.htm

Reducing sugar in packaged foods can prevent disease in millions

August 27, 2021

Science Daily/Massachusetts General Hospital

Cutting 20% of sugar from packaged foods and 40% from beverages could prevent 2.48 million cardiovascular disease events (such as strokes, heart attacks, cardiac arrests), 490,000 cardiovascular deaths, and 750,000 diabetes cases in the U.S. over the lifetime of the adult population, according to micro-simulation study published in Circulation.

A team of researchers from Massachusetts General Hospital (MGH), the Friedman School of Nutrition Science & Policy at Tufts University, Harvard T.H. Chan School of Public Health and New York City Department of Health and Mental Hygiene (NYC DOH) created a model to simulate and quantify the health, economic, and equity impacts of a pragmatic sugar-reduction policy proposed by the U.S. National Salt and Sugar Reduction Initiative (NSSRI). A partnership of more than 100 local, state and national health organizations convened by the NYC DOH, the NSSRI released draft sugar-reduction targets for packaged foods and beverages in 15 categories in 2018. This February, NSSRI finalized the policy with the goal of industry voluntarily committing to gradually reformulate their sugary products.

Implementing a national policy, however, will require government support to monitor companies as they work toward the targets and to publicly report on their progress. The researchers hope their model will build consensus on the need for a national-sugar reformulation policy in the US. "We hope that this study will help push the reformulation initiative forward in the next few years," says Siyi Shangguan, MD, MPH, lead author and attending physician at MGH. "Reducing the sugar content of commercially prepared foods and beverages will have a larger impact on the health of Americans than other initiatives to cut sugar, such as imposing a sugar tax, labeling added sugar content, or banning sugary drinks in schools."

Ten years after the NSSRI policy goes into effect, the U.S. could expect to save $4.28 billion in total net healthcare costs, and $118.04 billion over the lifetime of the current adult population (ages 35 to 79), according to the model. Adding the societal costs of lost productivity of Americans developing diseases from excessive sugar consumption, the total cost savings of the NSSRI policy rises to $160.88 billion over the adult population's lifetime. These benefits are likely to be an underestimation since the calculations were conservative. The study also demonstrated that even partial industry compliance with the policy could generate significant health and economic gains.

The researchers found that the NSSRI policy became cost-effective at six years and cost-saving at nine years. The policy could also reduce disparities, with the greatest estimated health gains among Black and Hispanic adults, and Americans with lower income and less education -- populations that consume the most sugar as a historical consequence of inequitable systems.

Product reformulation efforts have been shown to be successful in reducing other harmful nutrients, such as trans fats and sodium. The U.S., however, lags other countries in implementing strong sugar-reduction policies, with countries such as the UK, Norway, and Singapore taking the lead on sugar-reformulation efforts. The US may yet become a leader in protecting its people from the dangers of excessive sugar consumption if the NSSRI's proposed sugar-reduction targets are achieved. "The NSSRI policy is by far the most carefully designed and comprehensive, yet achievable, sugar-reformulation initiative in the world," says Shangguan.

Consuming sugary foods and beverages is strongly linked to obesity and diseases such as type 2 diabetes and cardiovascular disease, the leading cause of mortality in the U.S. More than two in five American adults are obese, one in two have diabetes or prediabetes, and nearly one in two have cardiovascular disease, with those from lower-income groups being disproportionately burdened.

"Sugar is one of the most obvious additives in the food supply to reduce to reasonable amounts," says Dariush Mozaffarian, MD, DrPH, co-senior author and dean of the Friedman School of Nutrition Science and Policy at Tufts University. "Our findings suggest it's time to implement a national program with voluntary sugar reduction targets, which can generate major improvements in health, health disparities, and healthcare spending in less than a decade."

https://www.sciencedaily.com/releases/2021/08/210827082431.htm

Pecan-enriched diet shown to reduce cholesterol

People at risk for cardiovascular disease showed improvements

August 23, 2021

Science Daily/University of Georgia

While the proper pronunciation of pecan remains a subject of debate, University of Georgia researchers have shown the tree nut can dramatically improve a person's cholesterol levels.

Participants at risk for cardiovascular disease who ate pecans during an eight-week intervention showed significant improvements in total cholesterol, triglycerides and low-density lipoprotein (LDL), or "bad" cholesterol, in a study conducted by researchers in the UGA College of Family and Consumer Sciences.

"This dietary intervention, when put in the context of different intervention studies, was extremely successful," said Jamie Cooper, a professor in the FACS department of nutritional sciences and one of the study's authors. "We had some people who actually went from having high cholesterol at the start of the study to no longer being in that category after the intervention."

Researchers saw an average drop of 5% in total cholesterol and between 6% and 9% in LDL among participants who consumed pecans.

For context, researchers referred to a previous meta-analysis of 51 exercise interventions designed to lower cholesterol that reported an average reduction of 1% in total cholesterol and 5% in LDL cholesterol.

"The addition of pecans to the diet not only produced a greater and more consistent reduction in total cholesterol and LDL compared to many other lifestyle interventions, but may also be a more sustainable approach for long-term health," Cooper said. "Some research shows that even a 1% reduction in LDL is associated with a small reduction of coronary artery disease risk, so these reductions are definitely clinically meaningful."

Researchers assigned 52 adults between the ages of 30 and 75 who were at higher risk for cardiovascular disease to one of three groups.

One group consumed 68 grams or about 470 calories of pecans a day as part of their regular diet; a second group substituted pecans for a similar amount of calories from their habitual diet, and a control group did not consume pecans.

At eight weeks, participants consumed a high-fat meal to determine changes in blood lipids and the amount of glucose, or sugar, in the blood.

Fasted blood lipids showed similar improvements among the two pecan groups while post-meal triglycerides were reduced in the group that added pecans. Post-meal glucose was lowered in the group that substituted pecans.

"Whether people added them or substituted other foods in the diet for them, we still saw improvements and pretty similar responses in total cholesterol and LDL cholesterol in particular," said Cooper, who also serves as director of the UGA Obesity Initiative.

Researchers pointed to the known bioactive properties of pecans for possible mechanisms driving the improvements.

Pecans are high in healthy fatty acids and fiber, both of which have been linked to lower cholesterol.

https://www.sciencedaily.com/releases/2021/08/210823125651.htm