1. Study suggests timing and duration of school lunch and recess related to food choices and physical activity

    May 8, 2017 by Ashley

    From the Experimental Biology 2017 press release:

    A new study finds that the duration and timing of lunch and recess is related to food choices and physical activity of school children. These findings could help schools make policies that promote healthier school lunches and increased physical activity during recess.

    Gabriella McLoughlin, a doctoral student at the University of Illinois, Urbana-Champaign, will present the new research at the American Society for Nutrition Scientific Sessions and annual meeting during the Experimental Biology 2017 meeting, to be held April 22-26 in Chicago.

    “Most research has focused solely on nutritional intake or physical activity during recess,” said Naiman Khan, PhD, assistant professor and leader of the research team. “This is the first study to objectively measure food intake at lunch in conjunction with physical activity and consider the influence of duration and timing.”

    For the study, the researchers assessed the lunch intake and physical activity of 151 fourth and fifth grade students from two low-income schools. Each school scheduled lunch either just before or immediately after recess.

    The researchers found that:

    • Although less food was wasted when recess was held before lunch, children consumed a greater proportion of vegetables when lunch was offered before recess.
    • When children had a longer time for a combined lunch and recess period, children were proportionally more physically active when lunch was offered before recess.
    • When the lunch-recess period was shorter, children were more active when recess was offered before lunch.

    “Overall, our findings suggest that recess and lunch behaviors are interrelated,” said McLoughlin. “However, the specific food choices and activity levels children engage in may be subject to the timing and duration of lunch and recess.” The relationships between food intake at lunch and physical activity were independent of factors previously shown to contribute to recess activity such as a child’s weight status and gender.

    The current guidelines from the Centers for Disease Control and Prevention recommend scheduling recess before lunch to reduce overall food waste. Although the new study also showed reduced food waste when recess is before lunch, the findings suggest that current recommendations may have unintended consequences for the types of foods consumed and could affect physical activity during recess, depending on the duration of the recess-lunch period.

    “We plan to communicate our findings to school teachers, administrators and policymakers to facilitate the implementation of evidence-based policies that support children’s ability to meet their daily physical activity and nutritional recommendations,” said Khan.

    Now that the researchers have extensive data on children’s physical activity patterns and lunch choices, the investigators are seeking federal funding to create feasible and sustainable school interventions based on their findings. They would also like to study whether policies regarding lunch and recess affect risk for obesity, success in academics and other markers of cognitive development in children.


  2. Study explains why food looks even better when dieting

    April 22, 2017 by Ashley

    From the Hiroshima University press release:

    Over recent decades, our understanding of hunger has greatly increased, but this new discovery turns things on their head. Up until now, scientists knew that leptin — a hormone released by fatty tissue, reduces appetite, while ghrelin — a hormone released by stomach tissue makes us want to eat more. These hormones, in turn, activate a host of neurons in the brain’s hypothalamus — the body’s energy control center.

    The discovery of NPGL by Professor Kazuyoshi Ukena of Hiroshima University shows that hunger and energy consumption mechanisms are even more complex than we realized — and that NPGL plays a central role in what were thought to be well-understood processes.

    Professor Ukena first discovered NPGL in chickens after noticing that growing birds grew larger irrespective of diet — suggesting there was more to energy metabolism than meets the eye. Intrigued, the researchers at HU performed a DNA database search to see if mammals might also possess this elusive substance. They found that it exists in all vertebrates — including humans.

    In order to investigate its role, if any, in mammals, Professor Ukena’s team fed three groups of mice, on three distinct diets, to see how NPGL levels are altered. The first set of mice was fed on a low-calorie diet for 24 hours. The second group was fed on a high-fat diet for 5 weeks — and the third lucky group was fed on a high-fat diet, but for an extended period of 13 weeks.

    The mice fed on a low calorie diet were found to experience an extreme increase in NPGL expression, while the 5-week high-fat-diet group saw a large decrease in NPGL expression.

    Further analysis found that mice possess NPGL, and its associated neuron network, in the exact same locations of the brain as those regions already known to control appetite suppression and energy use.

    Professor Ukena proposes that NPGL plays a vital role in these mechanisms — increasing appetite when energy levels fall and reducing appetite when an energy overload is detected — together, helping to keep us at a healthy and functioning weight, and more importantly alive!

    As NPGL levels greatly increased in mice exposed to a low calorie diet, Professor Ukena believes it is an appetite promoter, working in opposition to appetite suppressing hormones such as leptin. Backing this hypothesis up, it was found that mice directly injected with NPGL exhibited a voracious appetite.

    Interestingly NPGL levels, which plummeted in the 5-week-long high-fat-diet mice — fell back to normal levels in mice who gorged themselves for the longer period of 13 weeks.

    It is proposed that exposure to high-fat diets for long periods of time lead to insensitivity to leptin’s appetite-suppressing effects, and so NPGL — even at normal levels — leads to weight gain and obesity, showing that the body can only do so much to keep our weight in check.

    Professor Ukena says that further study is required to understand the interaction of previously known appetite mechanisms with this new kid on the homeostasis block. It does seem however, that we still have a lot to learn about appetite, hunger, and energy consumption. It is hoped that this study into mammalian NPGL adds another piece to the puzzle.

    What is certain — but you knew this already — is that dieting is difficult. The discovery and study of mammalian NPGL helps explain why, and provides a plausible excuse for those whose good intentions fall short.


  3. Study suggests Marmite may affect brain function

    April 12, 2017 by Ashley

    From the University of York press release:

    Scientists at the University of York have discovered a potential link between eating Marmite and activity in the brain, through the apparent increase of a chemical messenger associated with healthy brain function.

    Participants consuming a teaspoon of Marmite every day for a month, compared to a control group who consumed peanut butter, showed a substantial reduction of around 30 per cent in their brain’s response to visual stimuli, measured by recording electrical activity using electroencephalography (EEG).

    Researchers think this may be due to the prevalence of vitamin B12 in Marmite increasing levels of a specific neurotransmitter — known as GABA — in the brain.

    GABA inhibits the excitability of neurons in the brain, with the chemical acting to ‘turn down the volume’ of neural responses in order to regulate the delicate balance of activity needed to maintain a healthy brain.

    As Marmite consumption appears to increase GABA levels, this study is the first to show that dietary intervention may affect these neural processes. GABA imbalances are also associated with a variety of neurological disorders.

    Anika Smith, PhD student in York’s Department of Psychology and first author of the study, said: “These results suggest that dietary choices can affect the cortical processes of excitation and inhibition — consistent with increased levels of GABA — that are vital in maintaining a healthy brain.

    “As the effects of Marmite consumption took around eight weeks to wear off after participants stopped the study, this suggests that dietary changes could potentially have long-term effects on brain function.

    “This is a really promising first example of how dietary interventions can alter cortical processes, and a great starting point for exploring whether a more refined version of this technique could have some medical or therapeutic applications in the future. Of course, further research is needed to confirm and investigate this, but the study is an excellent basis for this.”

    Dr Daniel Baker, Lecturer in the Department of Psychology and senior author of the paper, said: “The high concentration of Vitamin B12 in Marmite is likely to be the primary factor behind results showing a significant reduction in participants’ responsiveness to visual stimuli.

    “Since we’ve found a connection between diet and specific brain processes involving GABA, this research paves the way for further studies looking into how diet could be used as a potential route to understanding this neurotransmitter.

    “Although GABA is involved in various diseases we can make no therapeutic recommendations based on these results, and individuals with a medical condition should always seek treatment from their GP.”


  4. Blueberry concentrate improves brain function in older people

    March 20, 2017 by Ashley

    From the University of Exeter press release:

    Blueberries

    Drinking concentrated blueberry juice improves brain function in older people, according to research by the University of Exeter.

    In the study, healthy people aged 65-77 who drank concentrated blueberry juice every day showed improvements in cognitive function, blood flow to the brain and activation of the brain while carrying out cognitive tests.

    There was also evidence suggesting improvement in working memory.

    Blueberries are rich in flavonoids, which possess antioxidant and anti-inflammatory properties.

    Dr Joanna Bowtell, head of Sport and Health Sciences at the University of Exeter, said: “Our cognitive function tends to decline as we get older, but previous research has shown that cognitive function is better preserved in healthy older adults with a diet rich in plant-based foods.

    “In this study we have shown that with just 12 weeks of consuming 30ml of concentrated blueberry juice every day, brain blood flow, brain activation and some aspects of working memory were improved in this group of healthy older adults.”

    Of the 26 healthy adults in the study, 12 were given concentrated blueberry juice — providing the equivalent of 230g of blueberries — once a day, while 14 received a placebo.

    Before and after the 12-week period, participants took a range of cognitive tests while an MRI scanner monitored their brain function and resting brain blood flow was measured.

    Compared to the placebo group, those who took the blueberry supplement showed significant increases in brain activity in brain areas related to the tests.

    The study excluded anyone who said they consumed more than five portions of fruit and vegetables per day, and all participants were told to stick to their normal diet throughout.

    Previous research has shown that risk of dementia is reduced by higher fruit and vegetable intake, and cognitive function is better preserved in healthy older adults with a diet rich in plant-based foods.

    Flavonoids, which are abundant in plants, are likely to be an important component in causing these effects.


  5. Mediterranean diet may have lasting effects on brain health

    January 13, 2017 by Ashley

    From the American Academy of Neurology (AAN) media release:

    healthy, vital seniorA new study shows that older people who followed a Mediterranean diet retained more brain volume over a three-year period than those who did not follow the diet as closely.

    The study is published in the January 4, 2017, online issue of Neurlogy®, the medical journal of the American Academy of Neurology. But contrary to earlier studies, eating more fish and less meat was not related to changes in the brain.

    The Mediterranean diet includes large amounts of fruits, vegetables, olive oil, beans and cereal grains such as wheat and rice, moderate amounts of fish, dairy and wine, and limited red meat and poultry.

    As we age, the brain shrinks and we lose brain cells which can affect learning and memory,” said study author Michelle Luciano, PhD, of the University of Edinburgh in Scotland. “This study adds to the body of evidence that suggests the Mediterranean diet has a positive impact on brain health.”

    Researchers gathered information on the eating habits of 967 Scottish people around age 70 who did not have dementia. Of those people, 562 had an MRI brain scan around age 73 to measure overall brain volume, gray matter volume and thickness of the cortex, which is the outer layer of the brain. From that group, 401 people then returned for a second MRI at age 76. These measurements were compared to how closely participants followed the Mediterranean diet.

    The participants varied in how closely their dietary habits followed the Mediterranean diet principles. People who didn’t follow as closely to the Mediterranean diet were more likely to have a higher loss of total brain volume over the three years than people who followed the diet more closely. The difference in diet explained 0.5 percent of the variation in total brain volume, an effect that was half the size of that due to normal aging.

    The results were the same when researchers adjusted for other factors that could affect brain volume, such as age, education and having diabetes or high blood pressure [hypertension].

    There was no relationship between grey matter volume or cortical thickness and the Mediterranean diet.

    The researchers also found that fish and meat consumption were not related to brain changes, which is contrary to earlier studies.

    It’s possible that other components of the Mediterranean diet are responsible for this relationship, or that it’s due to all of the components in combination,” Luciano said.

    Luciano noted that earlier studies looked at brain measurements at one point in time, whereas the current study followed people over time.

    “In our study, eating habits were measured before brain volume was, which suggests that the diet may be able to provide long-term protection to the brain,” said Luciano. “Still, larger studies are needed to confirm these results.”

     


  6. Vitamin D supplements may benefit children with autism spectrum disorder

    December 13, 2016 by Ashley

    From the Wiley media release:

    vitaminsVitamin D supplementation improved symptoms of autism in a recent trial.

    Studies have shown an association between the risk of autism spectrum disorder and vitamin D insufficiency. In this latest study, 109 children with autism spectrum disorder were randomized to receive four months of vitamin D3 supplementation or a placebo.

    Autism symptoms — such as hyperactivity, social withdrawal, and others — improved significantly following vitamin D3 supplementation but not after receiving placebo,” said Dr. Khaled Saad, lead author of the Journal of Child Psychology and Psychiatry study.

     


  7. Discrimination Based on Weight Doubles Health Risks

    October 21, 2016 by Ashley

    From the University of Rhode Island media release:

    obesityWe all know that carrying extra pounds can be bad for your health. Now a URI professor has found that how society treats overweight people makes matters worse.

    Maya Vadiveloo, assistant professor of nutrition and food sciences in the College of Health Sciences, and Josiemer Mattei, assistant professor of nutrition at Harvard University T.H. Chan School of Public Health, analyzed weight discrimination data from the long-term national study, Midlife Development in the United States.

    The researchers focused on respondents who reported regularly experiencing discrimination because of their weight. The study asked whether they were treated discourteously, called names, or made to feel inferior. Those who experienced weight discrimination over a 10-year period had twice the risk of high allostatic load, the cumulative dysfunction of bodily systems from chronic stress, they found. That stress can lead to heart disease, diabetes, inflammation and other disorders, increasing risk of death.

    “It is a pretty big effect,” Vadiveloo, of North Kingstown, says of the findings. “Even if we accounted for health effects attributed to being overweight, these people still experience double the risk of allostatic load because of weight discrimination.”

    The findings, published in the August issue of Annals of Behavioral Medicine, expose flaws in society’s approach to weight control, Vadiveloo says. “The main message is to be aware that the way we treat people may have more negative effects than we realize,” she says. “Our paper highlights the importance of including sensitivity and understanding when working with individuals with obesity and when developing public health campaigns.”

    People who experience weight discrimination often shun social interaction and skip doctor visits, she notes. “There is so much shaming around food and weight. We need to work together as a nation on improving public health and clinical support for individuals with obesity and targeting environmental risk factors,” she says. For example, Vadiveloo suggests developing strategies to make healthy foods affordable and creating safe places for people to be active.

    Vadiveloo hopes to address the topic in the classroom and revisit data from the nearly 1,000 respondents to explore whether having more social support or positive coping strategies reduces negative health effects of weight discrimination.


  8. Blueberries, the well-known super fruit, could help fight Alzheimer’s

    March 17, 2016 by Ashley

    From the American Chemical Society media release:

    [ File # csp7675513, License # 1824922 ] Licensed through http://www.canstockphoto.com in accordance with the End User License Agreement (http://www.canstockphoto.com/legal.php) (c) Can Stock Photo Inc. / Fotosmurf

    The blueberry, already labeled a ‘super fruit’ for its power to potentially lower the risk of heart disease and cancer, also could be another weapon in the war against Alzheimer’s disease.

    New research being presented today further bolsters this idea, which is being tested by many teams. The fruit is loaded with healthful antioxidants, and these substances could help prevent the devastating effects of this increasingly common form of dementia, scientists report.

    The researchers present their work today at the 251st National Meeting & Exposition of the American Chemical Society (ACS).

    “Our new findings corroborate those of previous animal studies and preliminary human studies, adding further support to the notion that blueberries can have a real benefit in improving memory and cognitive function in some older adults,” says Robert Krikorian, Ph.D., leader of the research team. He adds that blueberries’ beneficial effects could be due to flavonoids called anthocyanins, which have been shown to improve animals’ cognition.

    Currently 5.3 million people suffer from Alzheimer’s disease. But that number is expected to increase, Krikorian notes, as the U.S. population ages. By 2025, the number of Americans with this degenerative disorder could rise 40 percent to more than 7 million, and it could almost triple by 2050, according to the Alzheimer’s Association.

    In an effort to find ways to slow down this alarming trend, Krikorian and colleagues at University of Cincinnati Academic Health Center conducted two human studies to follow up on earlier clinical trials.

    One study involved 47 adults aged 68 and older, who had mild cognitive impairment, a risk condition for Alzheimer’s disease. The researchers gave them either freeze-dried blueberry powder, which is equivalent to a cup of berries, or a placebo powder once a day for 16 weeks.

    “There was improvement in cognitive performance and brain function in those who had the blueberry powder compared with those who took the placebo,” Krikorian says. “The blueberry group demonstrated improved memory and improved access to words and concepts.” The team also conducted functional magnetic resonance imaging (fMRI), which showed increased brain activity in those who ingested the blueberry powder.

    The second study included 94 people aged 62 to 80, who were divided into four groups. The participants didn’t have objectively measured cognitive issues, but they subjectively felt their memories were declining. The groups received blueberry powder, fish oil, fish oil and powder or placebo.

    “The results were not as robust as with the first study,” Krikorian explained. “Cognition was somewhat better for those with powder or fish oil separately, but there was little improvement with memory.” Also, fMRI results also were not as striking for those receiving blueberry powder. He says that the effect may have been smaller in this case because these participants had less severe issues when they entered the study.

    Krikorian said the two studies indicate that blueberries may be more effective in treating patients with cognitive impairments, but may not show measurable benefit for those with minor memory issues or who have not yet developed cognitive problems.

    In the future, the team plans to conduct a blueberry study with a younger group of people, aged 50 to 65. The group would include people at risk of developing Alzheimer’s, such as those who are obese, have high blood pressure or high cholesterol. This work could help the researchers determine if blueberries could help prevent the onset of Alzheimer’s symptoms.

     


  9. Overeating and depressed? There’s a connection, and maybe a solution

    January 8, 2016 by Ashley

    From the Yale University media release:

    midnight snackChronic overeating and stress are tied to an increased risk of depression and anxiety, and in a new study, Yale researchers explain why that happens and suggest a possible solution.

    The researchers report that the anesthetic ketamine reverses depression-like symptoms in rats fed a high-fat diet in a similar way it combats depression and synaptic damage of chronic stress in people.

    The effects of a high-fat diet overlap with those of chronic stress and could also be a contributing factor in depression as well as metabolic disorders such as Type 2 diabetes,” said Ronald Duman, the Elizabeth Mears and House Jameson Professor of Psychiatry, professor of neurobiology, and senior author of the paper published in the journal Neuropharmacology.

    Scientists at Yale have shown that ketamine, also known as “Special K” and abused as a recreational drug, can quickly and dramatically reduce symptoms of chronic depression in patients who are resistant to typical antidepressant agents. Subsequent research showed that ketamine activates the mTORC pathway, which regulates the synthesis of proteins involved in creation of synaptic connections in the brain that are damaged by stress and depression.

    The pathway is also involved in cellular responses to energy and metabolism, and people with metabolic disorders like Type 2 diabetes are also at higher risk of depression. A Yale team headed by lead author Sophie Dutheil in Duman’s lab decided to explore whether diet might influence behavior of rats fed six times the normal amount of fat. They found that after four months of the diet, pathways involved with both synaptic plasticity and metabolism were disrupted, and the rats exhibited signs of depression and anxiety.

    They also found that a single low dose of ketamine reversed those symptoms quickly, and reversed the disruption of mTORC signaling pathways.

    Duman cautioned that the effects of ketamine on metabolism need more research and its proper dosage and use for depression are still a subject of clinical trials.