Jet lag disorder associated with shift work can lead to brain changes increasing appetite

October 11, 2023

Science Daily/University of Bristol

Scientists have uncovered why night shift work is associated with changes in appetite in a new University of Bristol-led study. The findings, published in Communications Biology, could help the millions of people that work through the night and struggle with weight gain.

Scientists from Bristol and the University of Occupational and Environmental Health in Japan, sought to understand how 'circadian misalignment' -- a phenomenon commonly associated with 'jet-lag' whereby the body's biological clock is disrupted -- affects the hormones responsible for regulating appetite.

Prevalent in night shift workers, in this new study, the international team reveal how circadian misalignment can profoundly alter the brain's regulation of hormones controlling hunger to the detriment of metabolic health.

The team focused on glucocorticoid hormones in the adrenal gland which regulate many physiological functions including metabolism and appetite. Glucocorticoids are known to directly regulate a group of brain peptides controlling appetitive behaviour, with some increasing appetite (orexigenic) and some decreasing appetite (anorexigenic).

In an experiment using animal models, comprising a control group and a out-of-phase 'jet-lagged' group, the team found misalignment between light and dark cues led the out-of-phase group's orexigenic hypothalamic neuropeptides (NPY) to become dysregulated, driving an increased desire to eat significantly more during the inactive phase of the day.

Strikingly, the team discovered that rats in the control group ate 88.4% of their daily intake during their active phase, and only 11.6% during their inactive phase. In contrast, the 'jet-lagged' group consumed 53.8% of their daily calories during their inactive phase (without an increase in activity during this time). This equated to nearly five-times more (460% more) than what the control group consumed during the inactive phase. These results show that it is timing of consumption that has been affected.

This new discovery revealed how completely, and significantly, disordered the neuropeptides become when daily glucocorticoid levels are out of synch with light and dark cues. However, the authors suggest the neuropeptides identified in this study may be promising targets for drug treatments adapted to treat eating disorders and obesity.

Dr Becky Conway-Campbell, Research Fellow in Bristol Medical School: Translational Health Sciences (THS) and the study's senior author, said: "For people working throughout the night, a reversed body clock can play havoc with their health.

"For those who are working night shifts long-term, we recommend they try to maintain daylight exposure, cardiovascular exercise and mealtimes at regulated hours. However, internal brain messages to drive increased appetite are difficult to override with 'discipline' or 'routine' so we are currently designing studies to assess rescue strategies and pharmacological intervention drugs. We hope our findings also provide new insight into how chronic stress and sleep disruption leads to caloric overconsumption."

Stafford Lightman, Professor of Medicine at Bristol Medical School: THS and co-senior author on the study, added: "The adrenal hormone corticosterone, which is normally secreted in a circadian manner, is a major factor in the daily control of brain peptides that regulate appetite. Furthermore when we disturb the normal relationship of corticosterone with the day to night light cycle it results in abnormal gene regulation and appetite during the period of time that the animals normally sleep.

"Our study shows that when we disturb our normal bodily rhythms this in turn disrupts normal appetite regulation in a way that is at least in part a result of desynchrony between adrenal steroid hormone production and the timing of the light and dark cycle."

Dr Benjamin Flynn, one of the study's co-authors who conducted the study while at Bristol but is now based at the University of Bath, added: "This is further evidence of how phase shift 'jet-lag' affects feeding behaviours and neuronal gene expression -- data important for shift work co-morbidity research."

https://www.sciencedaily.com/releases/2023/10/231011182220.htm

How plant-derived nutrients can affect the gut and brain

Study tests link in overweight adults

October 10, 2023

Science Daily/Universität Leipzig

Prebiotics are used to foster the colonisation of beneficial bacteria in the gut. These indigestible dietary fibres are found in plant-derived foods such as onions, leeks, artichokes, wheat, bananas, and in high concentrations in chicory root. They support gut health by promoting the growth and activity of beneficial gut bacteria. Researchers have now investigated whether certain prebiotics can also influence brain function by improving communication between the gut microbiome and the brain.

The interventional study led by the University of Leipzig Medical Center indicates that consumption of high-dose dietary prebiotics leads to a reduction in reward-related brain activation in response to high-calorie food stimuli. "The results suggest a potential link between gut health and brain function, in this case food decision-making," says PD Dr Veronica Witte, co-author of the study and a scientist at the University of Leipzig Medical Center.

Young to middle-aged adults with overweight were selected for the study who followed an omnivorous, Western diet. The 59 volunteers consumed 30 grams of inulin, a prebiotic from chicory root, daily for 14 days. During functional MRI imaging, participants were shown pictures of food and asked how much they desired to eat the meals depicted. Following the MRI experiment, they were provided with their highest rated dish and asked to consume it.

The MRI examination was repeated at four timepoints, before and after the prebiotic administration and before and after a placebo phase in which the participants were given a preparation with identical energy density but without prebiotics. When the participants evaluated high-calorie foods, there was comparatively less activation of reward-related brain areas after they had consumed the prebiotic fibre. This effect was accompanied by a shift in the composition of the gut bacteria.

The findings, derived from advanced neuroimaging, next-generation sequencing of gut bacteria, and combined analyses of potential metabolic pathways, suggest that functional microbial changes may underlie the altered brain response towards high-caloric food cues. Fasting blood samples from the participants underwent analysis for gastrointestinal hormones, glucose, lipids, and inflammatory markers. In addition, gut microbiota and their metabolites, namely short-chain fatty acids, were measured in stool samples. The research was conducted within the Collaborative Research Centre 1052, "Obesity Mechanisms."

"Further studies are needed to investigate whether treatments that alter the microbiome could open up new avenues for less invasive approaches to the prevention and treatment of obesity. A better understanding of the underlying mechanisms between the microbiome, gut, and brain could help to develop new strategies that promote healthier eating habits in people at risk" says Dr Witte. A follow-up study is currently underway, examining the effects of long-term, high-dose prebiotic administration over six months on eating behaviour, brain function and body weight in people living with overweight and obesity.

https://www.sciencedaily.com/releases/2023/10/231010133552.htm

Scientists says identifying some foods as addictive could shift attitudes, stimulate research

October 9, 2023

Science Daily/Virginia Tech

Researchers from the United States, Brazil, and Spain, including scientists with the Fralin Biomedical Research Institute at VTC, published an analysis in a special edition of the British Medical Journal with a timely and controversial recommendation: It's time for an international shift in the way we think about ultra-processed food.

"There is converging and consistent support for the validity and clinical relevance of food addiction," said Ashley Gearhardt, the article's corresponding author and a psychology professor at the University of Michigan. "By acknowledging that certain types of processed foods have the properties of addictive substances, we may be able to help improve global health."

While people can give up smoking, drinking, or gambling, they can't stop eating, said co-author Alexandra DiFeliceantonio, assistant professor at the Fralin Biomedical Research Institute. The challenge, and the open and controversial question, is defining which foods have the most potential for addiction and why.

Their work was published Oct. 10 in Food For Thought, a special edition of the British Medical Journal, a high-impact publication and one of the world's oldest medical journals.

DiFeliceantonio is also associate director of the Fralin Biomedical Research Institute's Center for Health Behaviors Research and an assistant professor in the Department of Human Nutrition, Foods, and Exercise in the College of Agriculture and Life Sciences at Virginia Tech.

Not all foods have the potential for addiction, the researchers said.

"Most foods that we think of as natural, or minimally processed, provide energy in the form of carbohydrate or fat -- but not both," DiFeliceantonio said.

Researchers gave the example of an apple, salmon, and a chocolate bar. The apple has a carbohydrate to fat ratio of roughly 1-to-0, while the salmon has a ratio of 0-to-1. In contrast, the chocolate bar has a carbohydrate to fat ratio of 1-to-1, which appears to increase a food's addictive potential.

"Many ultra-processed foods have higher levels of both. That combination has a different effect on the brain," DiFeliceantonio said. Researchers also called for more study into the role of food additives used in industrial processing. Key takeaways from the analysis include:

• Behaviors around ultra-processed food, which are high in refined carbohydrates and added fats, may meet the criteria for diagnosis of substance use disorder in some people. Those behaviors include less control over intake, intense cravings, symptoms of withdrawal, and continued use despite such consequences as obesity, binge eating disorder, poorer physical and mental health, and lower quality of life.

• This global health challenge needs to consider geographic differences. In a review of 281 studies from 36 different countries, researchers found ultra-processed food addiction is estimated to occur in 14 percent of adults and 12 percent of children. In some countries, ultra-processed foods are a needed source of calories. Even within high-income countries, food deserts and other factors could limit access to minimally processed foods. People facing food insecurity are more reliant on ultra-processed foods, and therefore more likely to demonstrate food addiction, researchers noted.

• Viewing some foods as addictive could lead to novel approaches in the realm of social justice, clinical care, and public policy. Policies implemented in Chile and Mexico -- taxes, labelling, and marketing -- are associated with decreases in caloric intake and purchases of foods high in sugar, saturated fat, and salt, for example. And in the United Kingdom, a salt-reduction program was associated with a decline in deaths from stroke and coronary artery disease.

The co-authors represent international expertise on food addiction, nutrition physiology, gut-brain reward signaling, food policy, behavioral addiction, and eating disorders. They call for more study and science surrounding ultra-processed foods,

"Given how prevalent these foods are -- they make up 58 percent of calories consumed in the United States -- there is so much we don't know." DiFeliceantonio said.

The researchers call for more study into such areas as: how complex features of ultra-processed foods combine to increase their addictive potential; better defining which foods can be considered addictive; differences among countries and communities, including disadvantaged communities; the value of public-health messaging; and clinical guidelines for preventing, treating, and managing addiction to ultra-processed foods.

https://www.sciencedaily.com/releases/2023/10/231009191727.htm

Being a vegetarian may be partly in your genes

Large study found three genes strongly linked to vegetarianism

October 4, 2023

Science Daily/Northwestern University

From Impossible Burger to "Meatless Mondays," going meat-free is certainly in vogue. But a person's genetic makeup plays a role in determining whether they can stick to a strict vegetarian diet, a new Northwestern Medicine study has found.

The findings open the door to further studies that could have important implications regarding dietary recommendations and the production of meat substitutes.

"Are all humans capable of subsisting long term on a strict vegetarian diet? This is a question that has not been seriously studied,"said corresponding study author Dr. Nabeel Yaseen, professor emeritus of pathology at Northwestern University Feinberg School of Medicine.

A large proportion (about 48 to 64%) of self-identified "vegetarians" report eating fish, poultry and/or red meat, which Yaseen said suggests environmental or biological constraints override the desire to adhere to a vegetarian diet.

"It seems there are more people who would like to be vegetarian than actually are, and we think it's because there is something hard-wired here that people may be missing."

Several genes involved in lipid metabolism, brain function

To determine whether genetics contribute to one's ability to adhere to a vegetarian diet, the scientists compared UK Biobank genetic data from 5,324 strict vegetarians (consuming no fish, poultry or red meat) to 329,455 controls. All study participants were white Caucasian to attain a homogeneous sample and avoid confounding by ethnicity.

The study identified three genes that are significantly associated with vegetarianism and another 31 genes that are potentially associated. Several of these genes, including two of the top three (NPC1 and RMC1), are involved in lipid (fat) metabolism and/or brain function, the study found.

"One area in which plant products differ from meat is complex lipids," Yaseen said. "My speculation is there may be lipid component(s) present in meat that some people need. And maybe people whose genetics favor vegetarianism are able to synthesize these components endogenously. However, at this time, this is mere speculation and much more work needs to be done to understand the physiology of vegetarianism."

The study will be published Oct. 4 in the journal PLOS ONE. It is the first fully peer-reviewed and indexed study to look at the association between genetics and strict vegetarianism.

Why do most people eat meat?

Religious and moral considerations have been major motivations behind adopting a vegetarian diet, and recent research has provided evidence for its health benefits. And although vegetarianism is increasing in popularity, vegetarians remain a small minority of people worldwide. For example, in the U.S., vegetarians comprise approximately 3 to 4% of the population. In the U.K., 2.3% of adults and 1.9% of children are vegetarian.

This raises the question of why most people still prefer to eat meat products. The driving factor for food and drink preference is not just taste, but also how an individual's body metabolizes it, Yaseen said. For example, when trying alcohol or coffee for the first time, most people would not find them pleasurable, but over time, one develops a taste because of how alcohol or caffeine makes them feel.

"I think with meat, there's something similar," Yaseen said. "Perhaps you have a certain component -- I'm speculating a lipid component -- that makes you need it and crave it."

If genetics influence whether someone chooses to be a vegetarian, what does that mean for those who don't eat meat for religious or moral reasons?

"While religious and moral considerations certainly play a major role in the motivation to adopt a vegetarian diet, our data suggest that the ability to adhere to such a diet is constrained by genetics," Yaseen said. "We hope that future studies will lead to a better understanding of the physiologic differences between vegetarians and non-vegetarians, thus enabling us to provide personalized dietary recommendations and to produce better meat substitutes."

https://www.sciencedaily.com/releases/2023/10/231004150529.htm

Exercise and muscle regulation: Implications for diabetes and obesity

September 27, 2023

Science Daily/Deutsches Zentrum fuer Diabetesforschung DZD

Prediabetes is a condition that precedes type 2 diabetes and increases the risk of heart attack, kidney and eye disease, and several types of cancer. Currently, there is no approved drug therapy for prediabetes available. Scientists at the German Center for Diabetes Research (DZD) now show how and by which mechanisms prediabetes can be brought into remission, i.e. into a state in which blood glucose levels return to normal. The multicenter study of the DZD also shows that remission of prediabetes protects against type 2 diabetes and is associated with better kidney and vascular function in the long term. Interestingly, the underlying mechanisms are different from those in type 2 diabetes remission, the researchers report in The Lancet Diabetes & Endocrinology.

People with type 2 diabetes have an increased risk of heart attack, kidney disease and stroke, and a higher mortality risk. Type 2 diabetes was thought to be irreversible until a few years ago. We now know that type 2 diabetes can be put into remission in a significant number of individuals through substantial weight loss. However, this remission rarely lasts as most people typically develop type 2 diabetes again within a few years.

"We aimed to explore the feasibility of commencing earlier and implementing preventive measures already at a stage that precedes type 2 diabetes, namely prediabetes, with the aim of reversing it," elucidates senior author Prof. Dr. Andreas Birkenfeld, Medical Director of Medical Clinic IV at Tübingen University Hospital, and Director of the Institute for Diabetes Research and Metabolic Diseases of Helmholtz Munich at the University of Tübingen. This could be crucial for patients with prediabetes as they are at increased risk to develop type 2 diabetes as well as heart, kidney, and eye complications among others.

But what causes prediabetes to go into remission? Scientists from the Institute of Diabetes Research and Metabolic Diseases (IDM) at Helmholtz Munich and the Department of Diabetology, Endocrinology, and Nephrology at the University Hospital of Tübingen, conducted a post-hoc analysis on participants with prediabetes from the Prediabetes Lifestyle Intervention Study (PLIS) to investigate this question.

In this randomized-controlled multicenter study conducted by the DZD, 1,105 individuals with prediabetes underwent a lifestyle intervention involving a healthy diet and increased physical activity for a duration of one year. The researchers then assessed the 298 participants who had achieved a minimum weight loss of five percent as a result of the intervention. Responders were the participants whose fasting blood glucose, 2-hour glucose, and HbA1c levels had normalized within twelve months, indicating that they had gone into remission. Non-responders were individuals who did not achieve remission despite losing weight and still had prediabetes.

Contrary to the researchers' initial assumptions, it was not weight loss that distinguished those who went into remission from those who did not, as there was no difference in relative weight loss between responders and non-responders. However, individuals who achieved remission demonstrated a notable improvement in insulin sensitivity compared to non-responders. In essence, they were able to enhance their sensitivity to insulin, a hormone that lowers blood glucose levels, significantly more than those who did not respond. Nonetheless, the quantity of insulin secreted remained unaltered in both groups. This difference is critical compared to type 2 diabetes remission, which depends primarily on enhanced insulin secretion.

Reducing abdominal fat mass may help reverse prediabetes

To determine the cause of increased insulin sensitivity in responders, the researchers conducted a comparative analysis of the two groups. The responders had lost more abdominal fat compared to non-responders despite losing the same amount of body weight. Visceral abdominal fat is located directly in the abdominal cavity and surrounds the intestines. Its impact on insulin sensitivity is partially attributed to an inflammatory response in adipose tissue.

Indeed, participants who went into remission also had fewer inflammatory proteins in their blood. "Since the responders showed a reduction in abdominal fat in particular, it will be important in the future to identify the factors that promote the loss of this fat depot," says Arvid Sandforth, one of the two lead-authors. Surprisingly, there were no differences between the two groups in the reduction of liver fat, which is also an important risk factor for the development of diabetes.

Participants who achieved remission showed a 73 percent reduced risk of developing type 2 diabetes even two years after the end of the lifestyle intervention. They also showed reduced markers of kidney damage and better status of their blood vessels.

Currently, treatment of prediabetes consists of weight reduction and lifestyle improvement to delay the onset of type 2 diabetes -- but without glucose-based targets to guide the treatment process. The DZD's new analysis fills this gap: "Based on the new data, remission should be the new therapeutic target in people with prediabetes. This has the potential to change treatment practice and minimize the complication rate for our patients," says co-first author Prof. Dr. Reiner Jumpertz-von Schwartzenberg.

According to the study, remission in prediabetes can be considered to have occurred when fasting blood glucose falls below 100 mg/dl (5.6 mmol/l), 2-hour glucose below 140 mg/dl (7.8 mmol/l), and HbA1c below 5.7 percent. The likelihood of remission increases when body weight is reduced and waist circumference decreases by at least about 4 cm in women and about 7 cm in men. Researchers state that these criteria can now be used as biomarkers.

https://www.sciencedaily.com/releases/2023/09/230927155347.htm

Saturated fat may interfere with creating memories in aged brain

Study finds DHA protects brain cells from fat-related inflammation

September 27, 2023

Science Daily/Ohio State University

New research hints at a few ways fatty foods affect cells in the brain, a finding that could help explain the link between a high-fat diet and impaired memory -- especially as we age.

The Ohio State University study in cell cultures found the omega-3 fatty acid DHA may help protect the brain from an unhealthy diet's effects by curbing fat-induced inflammation at the cellular source.

Separate experiments using brain tissue from aging mice showed a high-fat diet may lead specific brain cells to overdo cell-signaling management in a way that interferes with the creation of new memories.

The same lab found in an earlier study in aging rats that a diet of highly processed ingredients led to a strong inflammatory response in the brain that was accompanied by behavioral signs of memory loss -- and that DHA supplementation prevented those problems.

"The cool thing about this paper is that for the first time, we're really starting to tease these things apart by cell type," said senior author Ruth Barrientos, an investigator in Ohio State's Institute for Behavioral Medicine Research and associate professor of psychiatry and behavioral health and neuroscience in the College of Medicine.

"Our lab and others have often looked at the whole tissue of the hippocampus to observe the brain's memory-related response to a high-fat diet. But we've been curious about which cell types are more or less affected by these saturated fatty acids, and this is our first foray into determining that."

The study was published recently in the journal Frontiers in Cellular Neuroscience.

For this work, the researchers focused on microglia, cells in the brain that promote inflammation, and hippocampal neurons, which are important for learning and memory. They used immortalized cells -- copies of cells taken from animal tissue that are modified to continuously divide and respond only to lab-based stimulation, meaning their behavior may not precisely match that of primary cells of the same type.

Researchers exposed these model microglia and neurons to palmitic acid, the most abundant saturated fatty acid in high-fat foods like lard, shortening, meat and dairy products, to observe how it affected gene activation in the cells as well as functioning of mitochondria, structures inside cells that have a primary metabolic role of generating energy.

Results showed the palmitic acid prompted gene expression changes linked to an increase in inflammation in both microglia and neurons, though microglia had a wider range of affected inflammatory genes. Pre-treatment of these cells with a dose of DHA, one of two omega-3 fatty acids in fish and other seafood and available in supplement form, had a strong protective effect against the increased inflammation in both cell types.

"Previous work has shown that DHA is protective in the brain and that palmitic acid has been detrimental to brain cells, but this is the first time we've looked at how DHA can directly protect against the effects of palmitic acid in those microglia, and we see that there is a strong protective effect," said Michael Butler, first author of the study and a research scientist in Barrientos' lab.

When it came to the mitochondria, however, DHA did not prevent the loss of function that followed exposure to palmitic acid.

"The protective effects of DHA might, in this context, be restricted to effects on gene expression related to the pro-inflammatory response as opposed to the metabolic deficits that the saturated fat also induced," Butler said.

In another set of experiments, the researchers looked at how a diet high in saturated fat influenced signaling in the brains of aged mice by observing another microglial function called synaptic pruning. Microglia monitor signal transmission among neurons and nibble away excess synaptic spines, the connection sites between axons and dendrites, to keep communication at an ideal level.

Microglia were exposed to mouse brain tissue containing both pre- and post-synaptic material from animals that had been fed either a high-fat diet or regular chow for three days.

The microglia ate the synapses from aged mice fed a high-fat diet at a faster rate than they ate synapses from mice fed a regular diet -- suggesting the high-fat diet is doing something to those synapses that gives the microglia a reason to eat them at a higher rate, Butler said.

"When we talk about the pruning, or refinement, that needs to occur, it's like Goldilocks: It needs to be optimal -- not too much and not too little," Barrientos said. "With these microglia eating away too much too soon, it outpaces the ability for these spines to regrow and create new connections, so memories don't solidify or become stable."

From here, the researchers plan to expand on findings related to synaptic pruning and mitochondria function, and to see how palmitic acid and DHA effects play out in primary brain cells from young versus aged animals.

https://www.sciencedaily.com/releases/2023/09/230927155308.htm

Early treatment of child obesity is effective

September 17, 2023

Science Daily/Karolinska Institutet

The early treatment of obesity in children is effective in both the short and long term, researchers from Karolinska Institutet report in a study published in The International Journal of Obesity.

The researchers followed over 170 young children in Sweden who had received treatment for diagnosed obesity. The children were recruited to the randomised controlled study when they were between four and six years old via children's clinics in Region Stockholm.

The children and their parents were randomly assigned to one of three treatment conditions: standard treatment, parental support group, or parental support group with follow-up telephone support.

The children and parents in the standard treatment group had meetings focusing on diet and exercise with a doctor, paediatrician and/or dietician. The two parental support groups did not involve the children and focused on how the parents could promote healthy lifestyles in the family in a positive way and without conflict.

"Such conversations can centre on how to set boundaries, how to teach children new behaviours and how to communicate with preschools, grandmothers, neighbours and other adults in the children's world," says principal investigator Paulina Nowicka, Associate Professor in Pediatric Science at the Department of Clinical Science, Intervention and Technology, Karolinska Institutet, and professor of Food studies, nutrition and dietetics at Uppsala University.

After attending the parental support groups, half of the participants were then randomly assigned a follow-up phone call.

Studies have been done on children who have been treated for obesity before," says Professor Nowicka. "But most of them have only been followed up after six months or a year, so we have no data on how the children fared over a longer period than that."

The study that she and her colleagues have now published suggest that early obesity treatment has a lasting effect.

"The children in all three groups improved their weight status and saw a reduction in their degree of obesity," she says. "The children whose parents received parental support had the best results, especially so those who also received follow-up phone calls. We also found that more children in this third group showed a clinically relevant improvement of their weight status associated with better metabolic health, by which I mean better levels of blood lipids and glucose."

According to Professor Nowicka, most parents know what kind of food they are to serve their children:

"They usually know this -- but what do you do with a child who loves food and always wants to eat, or one that's always hungry? How do you go about it without making a taboo of food?" she says. "You have to try to build a clear structure at home, one that makes the child know that lunch is on its way and know that they'll be getting supper."

She continues: "But you also need to do things together to strengthen family bonds, like getting the child involved in the cooking, giving the child vegetables if they're hungry and not rewarding them with food. It's also important to make sure that food isn't associated with emotions and achievement."

While obesity is difficult to treat, she explains, the study shows that intensive treatment is safe and efficacious for pre-school children:

"Treating children at that age is much more effective than if you start treating them in their teens," she says. "Some adolescents are looking at possible bariatric surgery and we hope that this can be avoided with earlier treatment."

https://www.sciencedaily.com/releases/2023/09/230917230749.htm

Living in a disadvantaged neighborhood affects food choices, weight gain and the microstructure of the brain

September 15, 2023

Science Daily/University of California - Los Angeles Health Sciences

A new study finds poor quality of available foods, increased intake of calories from foods high in trans-fatty acids, and environments that do not foster physical activity, all prevalent in disadvantaged neighborhoods, disrupt the flexibility of information processing in the brain that is involved in reward, emotion regulation, and cognition.

You are what you eat, according to the adage. But it's not just the body that's impacted. According to research from UCLA David Geffen School of Medicine, living in a disadvantaged neighborhood can affect food choices, weight gain and even the microstructure of the brain.

The study, appearing in Communications Medicine, a Nature journal, finds poor quality of available foods, increased intake of calories from foods high in trans-fatty acids, and environments that do not foster physical activity, all prevalent in disadvantaged neighborhoods, disrupt the flexibility of information processing in the brain that is involved in reward, emotion regulation, and cognition.

Previous research showed that living in a disadvantaged neighborhood can impact brain health, but in this study, researchers did a detailed analysis of the brain's cortex to determine how living in a disadvantaged area can change specific areas of the brain that play different roles.

"We found that neighborhood disadvantage was associated with differences in the fine structure of the cortex of the brain. Some of these differences were linked to higher body mass index and correlated with high intake of the trans-fatty acids found in fried fast food," said Arpana Gupta, PhD, co-Director of the Goodman-Luskin Center and Director of the Neuroimaging Core.

"Our results suggest that regions of the brain involved in reward, emotion, and the acquisition of knowledge and understanding might be affected by aspects of neighborhood disadvantage that contribute to obesity," said Gupta, senior author. "This highlights the importance of addressing dietary quality issues in disadvantaged neighborhoods to protect brain health."

Neighborhood disadvantage is defined by a combination of such factors as low median income, low education level, crowding, and lack of complete plumbing. This study included 92 participants -- 27 men and 65 women -- from the greater Los Angeles area. Demographic and body mass index information was collected, and neighborhood disadvantage was assessed as to its area deprivation index (ADI) using University of Wisconsin School of Medicine's Public Health's Neighborhood Atlas.

Earlier studies have found that people living in disadvantaged neighborhoods are at higher risk of obesity due to the poor quality of available foods, increased intake of calories from foods high in trans-fatty acids, and environments that do not foster physical activity.

In this study, researchers focused on the relationship between ADI and neuroimaging results at four levels of the brain cortex to investigate in more refined detail the connections between neighborhood disadvantage and brain structure. Participants underwent two types of MRI scans that, when analyzed in combination, provide insights into brain structure, signaling and function.

"Different populations of cells exist in different layers of the cortex, where there are different signaling mechanisms and information-processing functions," said Lisa Kilpatrick, PhD, a researcher in the Goodman-Luskin Microbiome Center focusing on brain signatures related to brain-body dysregulation, the study's first author. "Examining the microstructure at different cortical levels provides a better understanding of alterations in cell populations, processes and communication routes that may be affected by living in a disadvantaged neighborhood."

According to the results, worse ADI ratings were associated with communication changes in brain regions that are important for social interaction. Other changes occurred in regions involved in reward, emotion regulation, and higher cognitive processes -- and these changes appeared to be affected by trans-fatty acid intake. Together, the findings suggest that factors prevalent in disadvantaged neighborhoods that encourage poor diet and unhealthy weight gain "disrupt the flexibility of information processing involved in reward, emotion regulation, and cognition."

https://www.sciencedaily.com/releases/2023/09/230915105615.htm

A quarter of people are undoing the benefits of healthy meals by unhealthy snacking

September 14, 2023

Science Daily/King's College London

A quarter of people are undoing the benefits of healthy meals with unhealthy snacks, which increases the risk of strokes and cardiovascular disease.

The findings, published today in the European Journal of Nutrition by researchers from the School of Life Course & Population Sciences and ZOE, details the snacking habits of 854 people from the ZOE PREDICT study.

Researchers found that half of the participants do not match the healthiness of their meals to their snacks and vice versa. This difference has a negative effect on health measures, such as blood sugar and fat levels, and addressing this could be a simple diet strategy to improve health.

Dr Sarah Berry from King's College London and chief scientist at ZOE said: "Considering 95% of us snack, and that nearly a quarter of our calories come from snacks, swapping unhealthy snacks such as cookies, crisps and cakes to healthy snacks like fruit and nuts is a really simple way to improve your health."

The analysis showed that the UK is a nation of snackers, with 24% of our daily energy intake from snacks such as cereal bars, pastries and fruit. The average daily snack intake in people who snack -- 95% of the cohort -- was 2.28 snacks a day, with 47% of people eating two snacks a day and 29% of people eating more than two.

Contrary to popular belief, the analysis showed that snacking is not unhealthy -- as long as the snacks were healthy. People who ate high-quality snacks like nuts and fresh fruits frequently were more likely to have a healthy weight compared to those who don't snack at all or those who snack on unhealthy foods. Analysis also showed good quality snacks can also result in better metabolic health and decreased hunger.

However, a quarter (26%) of the participants reported eating healthy main meals and poor-quality snacks. Poor-quality snacks, such as highly processed food and sugary treats, were associated with poorer health markers and left people feeling hungry. Unhealthy snacks were linked with higher BMI, higher visceral fat mass and higher postprandial -- the period after eating a meal -- triglycerides concentrations, all of which are associated with metabolic disease such as stroke, cardiovascular disease and obesity.

The most popular snacks consumed were cookies, fruit, nuts and seeds, cheese and butter, cakes and pies and granola or cereal bars. The greatest contribution to calorie intake were cakes and pies (14%), breakfast cereals (13%), ice cream and frozen dairy desserts (12%), donuts and pastries (12%), candy (11%), cookies and brownies (11%), nuts and seeds (11%).

The timing of the snacking can also be crucial to your health, as analysis showed snacking after 9pm was associated with poorer blood markers compared to all other snacking times. Snackers at this time tended to eat energy-dense foods which were high in fat and sugar.

Dr Kate Bermingham from King's College London and senior scientist at ZOE said: "This study contributes to the existing literature that food quality is the driving factor in positive health outcomes from food. Making sure we eat a balanced diet of fruit, vegetables, protein and legumes is the best way to improve your health."

https://www.sciencedaily.com/releases/2023/09/230914224038.htm

Older adults with digestive diseases experience higher rates of loneliness, depression

September 12, 2023

Science Daily/Michigan Medicine - University of Michigan

A team of gastroenterologists and hepatologists examine psychosocial factors in older Americans with gastrointestinal conditions.

While life expectancy rates for older Americans are rising, nearly 40% of adults report living with a digestive disease of some kind.

"Many people don't realize that these conditions are very common in ambulatory care," said Michigan Medicine gastroenterologist Shirley Ann Cohen-Mekelburg, M.D., who specializes in conditions like inflammatory bowel disease, Crohn's disease and ulcerative colitis.

"Ultimately, this creates an excess in health care spending in the United States. Not only are these conditions debilitating for the millions of people living with them, but they're also very expensive to treat."

Cohen-Mekelburg says that in recent years, there has been a greater emphasis among providers in detecting why so many Americans are developing digestive diseases.

However, she notes that current approaches often fail to consider how things like psychosocial factors contribute to these conditions.

"As physicians, it's important for us to pay attention to psychosocial factors involved in the lives of our patients, but they often go overlooked," she said.

"These factors have the potential to significantly impact gastrointestinal health, and they also play a crucial role in the overall wellbeing of our patients."

This notion inspired Cohen-Mekelburg and a team of fellow gastroenterologists and hepatologists to examine the rates of loneliness, depression and social isolation in older adults both with and without digestive diseases.

Their findings were recently published in Clinical Gastroenterology and Hepatology.

Cohen-Mekelburg notes that the team also "wanted to quantify these numbers with self-reported rates of poor health."

"Our research involved analyzing data from 2008 to 2016 from the University of Michigan Health and Retirement Study.

This is a longitudinal panel study that involves a representative sample of approximately 20,000 individuals in the U.S. who are 50 years and older, as well as their spouses," she said.

"It's important to note that loneliness refers to the subjective distressed feeling of being alone or lacking companionship. The correlation between loneliness and depression is well established."

However, Cohen-Mekelburg adds that social isolation refers to the "objective physical separation from other people, which is independent of psychological well-being."

"Therefore, there are people who live in isolation but are well-adapted, not lonely and report high psychological wellbeing. But on the other hand, there are also people who are socially connected, yet suffer from low psychological wellbeing and loneliness. This, despite having a strong social network."

Out of a pool of 7,110 participants, the team identified 56% of individuals with a digestive disease and 44% without one.

"Overall, 60.4% and 55.6% of respondents with and without digestive diseases reported loneliness, while 12.7% and 7.5% reported severe depression, and 8.9% and 8.7% reported social isolation, respectively," said Cohen-Mekelburg.

"We found that individuals with a digestive disease were more likely to report 'poor-or-fair' health when compared to those without one. And among patients with a digestive disease, loneliness, as well as moderate to severe depression, were associated with greater odds of self-reporting 'poor-or-fair' health."

Cohen-Mekelburg says that she hopes these findings eventually empower gastroenterologists to "screen patients for depression and loneliness," in addition to their physical symptoms. "By doing this, providers can better establish care pathways for mental health treatment for their patients, which is hugely important," she said.

"Our research shows that gastroenterologists are in a unique position to help their patients achieve good overall health. If you're a clinician who also happens to treat older adults, even better. Being aware of the link between loneliness, depressive symptoms and digestive diseases can really benefit your patients from a holistic perspective."

https://www.sciencedaily.com/releases/2023/09/230912165720.htm