Many Americans are counting their carbs – but what counts as a ‘low-carb’ diet?

Interest in low-carbohydrate (or “low-carb”) diets continues to grow. In fact, low-carb diets have doubled in popularity among US consumers over the last decade.1 Yet, despite the eating pattern’s popularity, confusion persists around what exactly qualifies as a low-carb lifestyle. Now, a scoping review published in Critical Reviews in Food Science and Nutrition sheds new light on the topic and suggests scientific consensus around the term is building. Of the more than 500 clinical trials reviewed, the majority defined a low-carb diet as either limiting carbohydrate intake to 30% or less or total calories or eating fewer than 100 grams of carbohydrates daily. The review included results from a total of 508 clinical studies published between 2002 and 2022, over half of which were randomized controlled trials and nearly one-third of which were government-funded.

“The sheer volume of clinical trials on low-carb diets published over the last two decades was striking,” notes principal investigator Dr. Taylor Wallace. “Any perception that there is a lack of scientific evidence on low-carbohydrate eating patterns, or even a lack of government-funded evidence on the matter, clearly is not supported by the data.”

The review also found that 152 of the studies included in the analysis were designed to assess a low-carbohydrate diet’s effect on weight or body composition. Notably, these studies are often excluded from consideration in several federal nutrition evidence review processes, such as updates to the Dietary Reference Intake (DRI) guidelines for carbohydrates and the Dietary Guidelines for Americans' assessment of low-carbohydrate dietary patterns. These guidelines serve as the basis for numerous public health and nutrition activities, including food and nutrition labeling, federal nutrition programs, patient counseling and public health education initiatives.2  

“While it may not be surprising to learn that so many studies assessing the impact of low-carb nutrition interventions are focused on weight-related outcomes, it is important to understand that translates into a wealth of clinical data that has no bearing on some of the most foundational tools in U.S. dietary guidance,” adds Wallace. “It leaves a lot of the scientific evidence on the table – given the high rates of overweight and obesity in this country.”

Additionally, the investigators noted key gaps in the published literature. Though most studies classified low-carbohydrate diets as either consuming 30% or less of total calories from carbohydrates or limiting carb intake to fewer than 100 grams per day, the findings also revealed discrepancies. Of the studies using percent of total calories as their parameter for defining a low-carb diet, percentages ranged from zero to 50% of total calories from carbohydrates. And, of the studies defining “low-carb” according to the number of grams of carbohydrates consumed daily, many used thresholds falling well below 100 grams per day.

“With both consumers and public health officials interested in understanding the potential benefits of low-carbohydrate eating patterns, arriving at a standardized consensus definition is non-negotiable and urgently needed,” says Wallace. The researchers note systematic reviews and dose-response meta-regressions utilizing patient-level data on carbohydrate intake, status markers and health are key next steps to informing a clear, consistent and broadly adopted definition of the term “low-carbohydrate.”

This research was funded through an unrestricted educational grant from Simply Good Foods USA, Inc. to Think Healthy Group, LLC. Simply Good Foods had no influence on the study design, conduct, execution, or writing of the manuscript.  Think Healthy Group, LLC strictly adheres to the American Society for Nutrition’s guiding principles for funding food science and nutrition research.

The article, “Defining “low-carb” in the scientific literature: A scoping review of clinical studies,” is published in Critical Reviews in Food Science and Nutrition. (doi: https://doi.org/10.1080/10408398.2023.2300705)

Asthma rates climb for high school students as cannabis use increases

 Asthma is more common among high school students who use cannabis, relative to those who do not and the prevalence of asthma increases with the frequency of its use among the students, according to a new study at Columbia University Mailman School of Public Health and the City University of New York. The findings are published in the journal Pediatric Pulmonology.

The paper entitled "Asthma prevalence among US 9th–12th graders who report past 30‐day cannabis use in 2019" sheds light on the correlation between recent cannabis use and asthma prevalence among American high school students, adjusting for demographic characteristics and cigarette use.

Data were drawn from the 2019 Youth Risk Behavior Surveillance System, a CDC national high school survey, which collects data from students in grades 9–12 across the U.S. bi‐annually. The research team, led by Renee Goodwin in the Department of Epidemiology at Columbia Public Health utilized logistical models to examine the prevalence of asthma with past 30-day cannabis use, current cigarette, alcohol, state-of-residence cannabis legal status, adjusting for sex, race and ethnicity, thus providing a valuable contribution to the understanding of the potential health impacts associated with cannabis use among adolescents.

Cannabis use was more common among female (17% vs. 14%, male users), Non-Hispanic Black and Hispanic youth relative to Non-Hispanic White youth (17% and 16% respectively vs. 14.6%). Cannabis use was much more common among the students who reported any past 30-day cigarette or alcohol use (45% vs. 6.5%, for non-users. Declines in cannabis use were observed independent of state-level cannabis law from 2013 to 2021 and cannabis use prevalence did not differ significantly by state-of-residence cannabis legal status among the 24 participating states in 2021.

Commenting on the significance of the research, Goodwin and colleagues believe that the study adds to the growing body of evidence linking cannabis use to adverse health outcomes among young people. “Understanding these associations is crucial for developing effective prevention and intervention strategies to protect the health and well-being of our youth."

Study urges people to think twice before going on a diet

A new qualitative study highlights the negative interpersonal and psychological consequences associated with “yo-yo dieting,” also known as weight cycling. The work underscores how toxic yo-yo dieting can be and how difficult it can be for people to break the cycle.

“Yo-yo dieting – unintentionally gaining weight and dieting to lose weight only to gain it back and restart the cycle – is a prevalent part of American culture, with fad diets and lose-weight-quick plans or drugs normalized as people pursue beauty ideals,” says Lynsey Romo, corresponding author of a paper on the study and an associate professor of communication at North Carolina State University.

“Based on what we learned through this study, as well as the existing research, we recommend that most people avoid dieting, unless it is medically necessary. Our study also offers insights into how people can combat insidious aspects of weight cycling and challenge the cycle.”

For the study, researchers conducted in-depth interviews with 36 adults – 13 men and 23 women – who had experienced weight cycling where they lost and regained more than 11 pounds. The goal was to learn more about why and how people entered the yo-yo dieting cycle and how, if at all, they were able to get out of it.

All the study participants reported wanting to lose weight due to social stigma related to their weight, and/or because they were comparing their weight to that of celebrities or peers.

“Overwhelmingly, participants did not start dieting for health reasons, but because they felt social pressure to lose weight,” Romo says.

The study participants also reported engaging in a variety of weight-loss strategies, which resulted in initial weight loss, but eventual regain.

Regaining the weight led people to feel shame and further internalize stigma associated with weight – leaving study participants feeling worse about themselves than they did before they began dieting. This, in turn, often led people to engage in increasingly extreme behaviors to try to lose weight again.

“For instance, many participants engaged in disordered weight management behaviors, such as binge or emotional eating, restricting food and calories, memorizing calorie counts, being stressed about what they were eating and the number on the scale, falling back on quick fixes (such as low-carb diets or diet drugs), overexercising, and avoiding social events with food to drop pounds fast,” says Romo. “Inevitably, these diet behaviors became unsustainable, and participants regained weight, often more than they had initially lost.”

“Almost all of the study participants became obsessed with their weight,” says Katelin Mueller, co-author of the study and graduate student at NC State. “Weight loss became a focal point for their lives, to the point that it distracted them from spending time with friends, family, and colleagues and reducing weight-gain temptations such as drinking and overeating.”

“Participants referred to the experience as an addiction or a vicious cycle,” Romo says. “Individuals who were able to understand and address their toxic dieting behaviors were more successful at breaking the cycle. Strategies people used to combat these toxic behaviors included focusing on their health rather than the number on the scale, as well as exercising for fun, rather than counting the number of calories they burned.

“Participants who were more successful at challenging the cycle were also able to embrace healthy eating behaviors – such as eating a varied diet and eating when they were hungry – rather than treating eating as something that needs to be closely monitored, controlled or punished.”

However, the researchers found the vast majority of study participants stuck in the cycle.

“The combination of ingrained thought patterns, societal expectations, toxic diet culture, and pervasive weight stigma make it difficult for people to completely exit the cycle, even when they really want to,” Romo says.

“Ultimately, this study tells us that weight cycling is a negative practice that can cause people real harm,” Romo says. “Our findings suggest that it can be damaging for people to begin dieting unless it is medically necessary. Dieting to meet some perceived societal standard inadvertently set participants up for years of shame, body dissatisfaction, unhappiness, stress, social comparisons, and weight-related preoccupation. Once a diet has begun, it is very difficult for many people to avoid a lifelong struggle with their weight.”

The paper, “A Qualitative Model of Weight Cycling,” is published in the journal Qualitative Health Research. The paper was co-authored by Sydney Earl, a Ph.D. student at NC State; and by Mary Obiol, an undergraduate at NC State.

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A walk in nature restores attention

 

Neural research conducted at Utah's Red Butte Garden uses EEG to measure brain activity on subjects after walks through nature and parking lots.

Peer-Reviewed Publication

UNIVERSITY OF UTAH

 

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A RESEARCH SUBJECT STROLLS THROUGH UNIVERSITY OF UTAH'S RED BUTTE GARDEN IN 2022 AS PART OF THE ATTENTION STUDY.

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CREDIT: AMY MCDONNELL, UNIVERSITY OF UTAH

New research from University of Utah psychology researchers is helping prove what American authors John Muir and Henry David Thoreau tried to teach more than 150 years ago: Time spent in nature is good for the heart and soul.

Amy McDonnell and David Strayer are showing it is good for your brain, too. Their latest research, conducted at the university’s Red Butte Garden, uses electroencephalography (EEG), which records electrical activity in the brain with small discs attached to the scalp, to measure participants’ attentional capacity.

“A walk in nature enhances certain executive control processes in the brain above and beyond the benefits associated with exercise,” concludes the study that appeared Tuesday in Scientific Reports, among the world’s most cited scientific journals. The paper contributes to growing body of scientific literature on the how natural settings contribute to a person’s physical and mental health. The university itself has recently established a new research group, Nature and Human Health Utah, that explores these issues and propose solutions for bridging the human-nature divide.

Many researchers suspect a primal need for nature is baked into humans’ DNA, and diminishing access to nature is putting our health at risk.

“There's an idea called biophilia that basically says that our evolution over hundreds of thousands of years has got us to have more of a connection or a love of natural living things,” said Strayer, a professor of psychology. “And our modern urban environment has become this dense urban jungle with cell phones and cars and computers and traffic, just the opposite of that kind of restorative environment.”

[You can see Strayer explore these ideas in his 2017 TEDx talk.]

Strayer’s past research into multitasking and distracted driving associated with cellphone use has drawn national attention. For the past decade, his lab has focused on how nature affects cognition. The new research was part of McDonnell’s dissertation as a grad student in Strayer’s Applied Cognition Lab. She has since completed her PhD and is continuing the attention research as a postdoctoral fellow with the University of Utah.

The study, conducted in 2022 between April and October, analyzed EEG data recorded on each of 92 participants immediately before and after they undertook a 40-minute walk.  Half walked through Red Butte, the arboretum in the foothills just east of the university, and half through the nearby asphalt-laden medical campus.

“We start out by having participants do a really draining cognitive task in which they count backwards from 1,000 by sevens, which is really hard,” McDonnel said. “No matter how good you are at mental math, it gets pretty draining after 10 minutes. And then right after that, we give them an attention task.”

The idea was to deplete the participants’ attentional reserves before doing the standardized “Attention Network Task” and going for the walk, which they do without their electronic devices or talking to anyone along the way. They are randomly selected to either walk through the least built-up part of the arboretum along Red Butte Creek or through the adjacent U medical campus and parking lots. Both routes covered two miles with similar amounts of elevation gain.

“The participants that had walked in nature showed an improvement in their executive attention on that task, whereas the urban walkers did not, so then we know it's something unique about the environment that you're walking in,” McDonnell said. “We know exercise benefits executive attention as well, so we want to make sure both groups have comparable amounts of exercise.”

What sets this study apart from much of the existing research into the human-nature nexus is its reliance on EEG data as opposed to surveys and self-reporting, which do yield helpful information but can be highly subjective.

“This is probably one of the most rigorous studies in terms of controlling for and making sure that it's really the exposure in Red Butte” resulting in the observed cognitive effects, Strayer said.

McDonnell fitted each participant with a cap with holes to support an array of 32 electrodes that contact the scalp with the help of a special gel.

“It has electrodes that are placed all over the surface of the scalp,” Strayer said. “It records really very, very small voltages, but it's an active electrode system that provides beautiful brain maps.”

The maps revealed three components of attention, alerting, orienting and executive control.

 Executive control occurs in the brain’s prefrontal cortex, an area critical for working memory, decision making, problem solving and coordinating disparate tasks.

“The kinds of things that we do on an everyday basis tend to heavily use those executive attentional networks,” Strayer said. “It's important in concentration and especially, so it's an essential component of higher order thinking.”

While the EEG and attention task results did not show much of a difference for alertness and orientation between the garden and the asphalt walkers, those on the nature walk exhibited improved executive control.

McDonnell and Strayer hope the findings can be refined to show what kind of natural settings result in optimal cognitive benefits, and how much exposure is needed to help.

“If you understand something about what's making us mentally and physically healthier, you could then potentially engineer our cities so that they supported that,” Strayer said.

The team is continuing the research at Red Butte, but now looking at how cellphone use affects the garden walkers’ responses. Strayer is sometimes asked why he studies both distraction and attention, which he sees as opposing sides of the same coin.

“It’s where the prefrontal cortex is overloaded, overstimulated, and you make all kinds of dangerous mistakes when you're multitasking behind the wheel,” he said. “But the antidote to that is being out in a natural environment, leave the phone in your pocket and then go out and walk the trails. The parts of the brain that have been overused during the daily commute are restored. You see and think more clearly.”

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JOURNAL

Scientific Reports

DOI

10.1038/s41598-024-52205-1 

Plant-based diets = negative affect on pregnancy and birth outcomes

Women who follow vegan diets during pregnancy may face higher risks of developing preeclampsia and of giving birth to newborns with lower birth weight, suggests a recent study published in Acta Obstetricia et Gynecologica Scandinavica.

For the study, 65,872 women identified themselves as omnivorous, 666 as fish/poultry vegetarians, 183 as lacto/ovo vegetarians, and 18 as vegans. Based on a questionnaire completed mid-pregnancy, investigators found that protein intake was lower among lacto/ovo vegetarians (13.3%) and vegans (10.4%) compared with omnivorous participants (15.4%). Micronutrient intake was also much lower among vegans, but when dietary supplements were considered, no major differences were observed.

Compared with omnivorous mothers, vegan mothers had a higher prevalence of preeclampsia (a pregnancy complication characterized by high blood pressure), and their newborns weighed an average of 240 g less.

“Further research is needed regarding possible causality between plant-based diets and pregnancy and birth outcomes, to strengthen the basis for dietary recommendations,” the authors wrote

URL upon publication: https://onlinelibrary.wiley.com/doi/10.1111/aogs.14778

 

Kiwifruit: a powerful mood booster

 Kiwifruit has proven itself as a powerful mood booster and new research from the University of Otago has shown just how fast its effects can be.

 

In a study, published in The British Journal of Nutrition, researchers found the furry fruit improved vitality and mood in as little as four days.

 

Co-author Professor Tamlin Conner, of the Department of Psychology, says the findings provide a tangible and accessible way for people to support their mental well-being.

 

“It’s great for people to know that small changes in their diet, like adding kiwifruit, could make a difference in how they feel every day.”

 

Vitamin C intake has been associated with improved mood, vitality, well-being, and lower depression, while vitamin C deficiency is associated with higher depression and cognitive impairment.

 

However, Professor Conner says limited research has assessed how quickly mood improvements occur after introducing vitamin C supplements or whole food sources.

 

The researchers aimed to fill that gap with an 8-week dietary intervention of 155 adults with low vitamin C.

 

Participants took daily either a vitamin C supplement, placebo, or two kiwifruit. They then reported their vitality, mood, flourishing, sleep quality, sleep quantity, and physical activity using smartphone surveys.

 

The researchers found kiwifruit supplementation improved vitality and mood within four days, peaking around 14-16 days, and improved flourishing from day 14. Vitamin C, on the other hand, marginally improved mood until day 12.

 

Lead author Dr Ben Fletcher, who conducted the research as part of his PhD at Otago, says understanding the nuances of when and how these effects occur day-to-day contributes to our knowledge of the potential benefits of vitamin C-rich foods and supplements on mental health.

 

“This helps us see that what we eat can have a relatively fast impact on how we feel.

 

“Our participants had relatively good mental health to begin with so had little room for improvement, but still reported the benefits of kiwifruit or vitamin C interventions,” he says.

 

He adds that, while vitamin C tablets showed some improvements, the study underscores the potential synergistic effects of consuming whole foods like kiwifruit.

 

“We encourage a holistic approach to nutrition and well-being, incorporating various nutrient-rich foods into your diet.”

 

In addition to the direct implications for individuals seeking to improve their mental well-being, Professor Conner says the study introduces a novel methodology in nutritional research.

 

“The use of intensive smartphone surveys offers a real-time understanding of the day-to-day changes in mood-related outcomes.”

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JOURNAL

British Journal Of Nutrition

DOI

10.1017/S0007114523002787 

Unintentional weight loss is a signal to see a doctor

 Unintentional weight loss is associated with an increase in the risk of a cancer diagnosis within the coming year, according to a study from Dana-Farber Cancer Institute.

“If you are losing weight and you aren’t trying to lose weight by making changes in your exercise routine or diet, people should see their doctor to consider possible causes,” says lead investigator Brian Wolpin, MD, MPH, Director of the Gastrointestinal Cancer Center at Dana-Farber and Director of the Hale Family Center for Pancreatic Cancer Research. “There are many conditions that can result in unexpected weight loss. Your doctor can determine if there is something that needs evaluation.”

The findings were published in the Journal of the American Medical Association on January 23, 2024.

Compared with participants who did not lose weight, recent weight loss was associated with significantly increased risk for several types of cancer, including upper gastrointestinal tract (including esophageal, stomach, liver, biliary tract, and pancreatic cancer), hematological (including non-Hodgkin lymphoma, multiple myeloma, and leukemia), colorectal, and lung cancers. However, recent weight loss wasn’t found to be associated with increased risk for other cancer types, such as breast cancer, genitourinary cancer, brain cancer, or melanoma.

“Unexpected weight loss can come from cancer or many other conditions,” says Wolpin. “Sometimes weight loss is due to more exercise or a healthier diet, and this can be beneficial to people’s health. However, when a patient experiences unintentional weight loss not due to healthier behaviors, seeing your primary care doctor is appropriate, so they can determine whether additional evaluation is necessary for other causes of weight loss, including cancer.”

The study assessed 157,474 participants in two large longitudinal studies: the Nurses’ Health Study, which enrolled nurses aged 30 to 55 starting in 1976, and the Health Professionals Follow-Up Study, which enrolled male health professionals aged 40 to 75 years starting in 1986. Participants were followed until 2016.

Weight was reported by participants every other year in a biennial questionnaire that also included questions about physical activity. The questionnaire requested responses about dietary changes every four years. This information enabled Wolpin and colleagues to assess each participant’s level of weight loss promoting behaviors. Weight loss promoting behaviors were classified into “high” for those making both dietary improvements and increases to physical activity, “medium” if they made only one change, and “low” if they made no changes to diet and exercise.

“We wanted to differentiate healthy weight loss from unhealthy weight loss,” says Qiaoli Wang, MD, PhD, a research fellow at Dana-Farber and the manuscript’s first author. “Healthy weight loss can come from dietary changes or increased exercise. But unhealthy weight loss that occurs unexpectedly can be due to an underlying cancer.”

Patients with advanced cancer often lose weight, but weight loss is often not thought to occur with early-stage disease. This study found that similar levels of weight loss occurred before diagnosis of both early and late-stage disease. This is important because unintentional weight loss could be a sign of a developing cancer that could help diagnose the cancer earlier when there’s a chance for more effective treatment.

The mechanisms by which cancer results in weight loss varies depending on the type of cancer. This study strengthens findings from past research that connected unexpected weight loss with an increased cancer risk. In previous research, weight data was collected by doctors from patients potentially seeking out care for an illness. In this study, weight data was collected prospectively and regularly for decades and was not dependent on doctor visits to identify weight changes. This study also considered all types of cancers. However, the two studies analyzed were focused on health professionals, which is not a group that is fully representative of the U.S. population.

Walking fitness can predict fracture risk in older adults

 

The ability to walk one kilometre (3/5 of a mile)

comfortably can help predict fracture risk, according to researchers at the Garvan Institute of Medical Research. The findings, published today in JAMA Network Open, suggest that simply asking a patient about walking limitation could allow clinicians to identify those in need of further bone health screening and prescribe interventions that could prevent fractures from occurring.

“We’ve discovered that trouble walking even short distances appears closely tied to higher fracture risk over the following five years,” says lead author of the study, Professor Jacqueline Center, Head of Garvan’s Clinical Studies and Epidemiology Lab. “Just a few simple questions about how far someone can walk could give doctors an early warning sign to check bone health.”

The researchers examined data on nearly 267,000 adults aged 45 and older from the Sax Institute’s 45 and Up Study, a major ongoing research initiative that has been tracking health outcomes in adults in NSW for more than 15 years. Participants were asked if health issues limited their ability to walk various distances, with answer options of ‘not at all,’ ‘a little,’ or ‘a lot’. The group was then followed for five years to track fracture outcomes.

The researchers found that one in five adults reported some walking limitation at the beginning of the study. Those with more difficulty walking were significantly more likely to experience a fracture during follow-up. For example, women who said they were limited ‘a lot’ in walking one kilometre had a 60% higher fracture risk than women with no limitation. For men, the increased risk was over 100%.

“We saw a clear ‘dose-response’ pattern, where greater walking limitation meant higher fracture risk. This suggests a direct relationship between low walking ability and weaker bones,” says first author of the study Dr Dana Bliuc, Senior Research Officer at Garvan.

Approximately 60% of all fractures in the study were attributable to some level of walking limitation. The link remained strong even after accounting for other factors like age, falls, prior fractures, and weight, and the findings were consistent across different fracture sites like hips, vertebrae, arms, and legs.

“In this generally healthy community-based population, we still found one in five people had trouble walking a kilometre,” says Professor Center. “We think this simple assessment could help identify many more at-risk individuals who may benefit from bone density screening or preventative treatment.”

Osteoporosis medications, lifestyle changes, and other interventions are available to improve bone strength and avoid first or repeat fractures. However, screening rates currently remain low, meaning many miss out on fracture risk assessments. Finding easy but accurate ways to detect at-risk people is an important target for research.

“Fracture risk assessment generally relies on a bone density test, which many people have not had when seeing their doctor,” says Professor Center. “Asking about walking ability takes just seconds and could be a free, non-invasive way to tell if someone needs their bones checked.”

The researchers stress that walking limitation may have many causes beyond weak bones, from heart disease to arthritis. However, a difficulty in walking even short distances appears closely tied to fracture risk independently.

“We hope these findings will encourage clinicians to consider walking ability as a red flag for possible bone health issues. For patients, if you can’t walk a full kilometre comfortably, it may be wise to ask your doctor about getting your bones checked,” says Dr Bliuc.

Occupational sitting time, leisure physical activity, and all-cause and cardiovascular disease mortality

 In a ne study published in  JAMA Network Open, involving 481,000 individuals over a mean follow-up period of nearly 13 years, individuals who predominantly engaged in sitting at work exhibited a higher risk of mortality from all causes and cardiovascular disease compared with those who predominantly did not sit. Individuals who predominantly sit at work would need to engage in an additional 15 to 30 minutes of physical activity per day to mitigate this increased risk and reach the same level of risk as individuals who predominantly do not sit at work.

Daily multivitamin supplements improve memory and slow cognitive aging in older adults

 

Third major study finds evidence that daily multivitamin supplements improve memory and slow cognitive aging in older adults

By 2060, according to the Alzheimer’s Association, nearly one in four Americans will be in an age bracket at elevated risk of cognitive decline and Alzheimer’s disease unless interventions can help preserve cognitive function before deficits begin. The COcoa Supplement and Multivitamin Outcomes Study (COSMOS) is a large-scale, nationwide, randomized trial rigorously testing cocoa extract and multivitamin supplements directed by researchers at Mass General Brigham. Two previously published studies of cognition in COSMOS suggested a positive effect for a daily multivitamin. COSMOS researchers now report the results of a third study of cognition in COSMOS, which focused on participants who underwent in-person assessments, together with the results of a combined analysis from the three separate studies. The results from this latest report confirm consistent and statistically significant benefits of a daily multivitamin versus placebo for both memory and global cognition. Results are published today in The American Journal of Clinical Nutrition.

“Cognitive decline is among the top health concerns for most older adults, and a daily supplement of multivitamins has the potential as an appealing and accessible approach to slow cognitive aging,” said first author Chirag Vyas, MBBS, MPH, instructor in investigation at the Department of Psychiatry at Massachusetts General Hospital (MGH), a founding member of the Mass General Brigham healthcare system.

In the in-clinic study the researchers administered detailed, in-person cognitive assessments among 573 participants in the subset of COSMOS known as COSMOS-Clinic. Within COSMOS, two previous studies had tested multivitamin supplementation on cognition using telephone-based cognitive assessments (COSMOS-MIND) and online web-based cognitive assessments (COSMOS-Web). In their prespecified analyses of data from COSMOS-Clinic, investigators observed a modest benefit for the multivitamin, compared to placebo, on global cognition over two years. There was a statistically significant benefit of multivitamin supplementation for change in episodic memory, but not in executive function/attention.

The team also conducted a meta-analysis based on the three separate studies, with non-overlapping COSMOS participants (ranging 2-3 years in treatment duration), which showed strong evidence of benefits for both global cognition and episodic memory. The authors estimate that the daily multivitamin slowed global cognitive aging by the equivalent of two years compared to placebo.

Vyas said, “The meta-analysis of three separate cognition studies provides strong and consistent evidence that taking a daily multivitamin, containing more than 20 essential micronutrients, helps prevent memory loss and slow down cognitive aging.” Olivia Okereke, MD SM, senior author of the report and director of Geriatric Psychiatry at MGH, added “These findings will garner attention among many older adults who are, understandably, very interested in ways to preserve brain health, as they provide evidence for the role of a daily multivitamin in supporting better cognitive aging.”

The overall COSMOS trial is led by JoAnn Manson, MD, DrPH, and Howard Sesso, ScD, MPH, both of Brigham and Women’s Hospital (BWH), also a founding member of Mass General Brigham.  Manson, co-author of the report and Chief of the Division of Preventive Medicine at BWH, commented: “The finding that a daily multivitamin improved memory and slowed cognitive aging in three separate placebo-controlled studies in COSMOS is exciting and further supports the promise of multivitamins as a safe, accessible and affordable approach to protecting cognitive health in older adults.”

The COSMOS consortium of cognitive studies represents a collaboration between MGH, BWH, Columbia University, and Wake Forest University, using both traditional and innovative approaches to assessing cognitive outcomes. These approaches allow large numbers of participants (>5,000 in total) to be included in cognitive studies in a high-quality and cost-efficient manner. COSMOS participants are aged 60 and older and reside throughout the U.S.

Sesso, also a co-author and the associate director of the BWH Division of Preventive Medicine, added: “With these three studies using different approaches for assessing cognition in COSMOS, each providing support for a daily multivitamin, it is now critical to understand the mechanisms by which a daily multivitamin may protect against memory loss and cognitive decline with a focus on nutritional status and other aging-related factors. For example, the modifying role of baseline nutritional status on protecting against cognitive decline has been shown for the COSMOS cocoa extract intervention. A typical multivitamin such as that tested in COSMOS contains many essential vitamins and minerals that could explain its potential benefits.”

Diets rich in plant protein may help women stay healthy as they age

 

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PHOTO ILLUSTRATION OF A SERVING OF NUTS, APPROXIMATELY THE SIZE OF A GOLF BALL.

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CREDIT: ALONSO NICHOLS/TUFTS UNIVERSITY

Women who consume higher amounts of protein, especially protein from plant-based sources, develop fewer chronic diseases and are more likely to be healthier overall as they age, according to a study led by researchers at the Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) at Tufts University and published Jan. 17 in The American Journal of Clinical Nutrition.

Analyzing self-reported data from more than 48,000 women, the researchers saw notably less heart disease, cancer, and diabetes, and cognitive and mental health decline, in those who included more protein in their diets from sources such as fruits, vegetables, bread, beans, legumes, and pasta, compared to those who ate less.

“Consuming protein in midlife was linked to promoting good health in older adulthood,” said Andres Ardisson Korat, a scientist at the HNRCA and lead author of the study. “We also found that the source of protein matters. Getting the majority of your protein from plant sources at midlife, plus a small amount of animal protein seems to be conducive to good health and good survival to older ages.”

Findings were derived from the seminal Harvard-based Nurses’ Health Study, which followed female health care professionals from 1984 to 2016. The women were between the ages of 38 and 59 in 1984 and deemed to be in good physical and mental health at the start of the study.

Ardisson Korat and fellow researchers, including senior author Qi Sun of the Harvard T.H. Chan School of Public Health, examined thousands of surveys collected every four years from 1984 to 2016 on how frequently people ate certain foods to pinpoint dietary protein and its effects on healthy aging. They calculated protein intake by multiplying the number of times each food item was consumed by its protein content and then, using the Harvard University Food Composition Database, totaling the amount of protein across all food items.

The researchers then compared the diets of women who didn’t develop 11 chronic diseases or lose a lot of physical function or mental health, with the diets of those who did. Women who ate more plant-based protein, which in 1984 was defined as protein obtained from bread, vegetables, fruits, pizza, cereal, baked items, mashed potatoes, nuts, beans, peanut butter, and pasta, were 46 percent more likely to be healthy into their later years. Those who consumed more animal protein such as beef, chicken, milk, fish/seafood, and cheese, however, were 6 percent less likely to stay healthy as they aged.

“Those who consumed greater amounts of animal protein tended to have more chronic disease and didn’t manage to obtain the improved physical function that we normally associate with eating protein,” said Ardisson Korat.

Animal protein was modestly tied with fewer physical limitations in older age, but plant protein had a stronger, more consistent correlation across all observed models, and was more closely linked with sound mental health later in life. For heart disease in particular, higher plant protein consumption came with lower levels of LDL cholesterol (“bad” cholesterol), blood pressure, and insulin sensitivity, while higher animal protein intake was tied to higher levels, along with increased insulin-like growth factor, which has been detected in multiple cancers.

Dairy protein alone (mainly milk, cheese, pizza, yogurt, and ice cream) was not significantly associated with better health status in older adulthood.

The team acknowledged that the benefits of plant protein might derive from components in plant-based food, rather than the protein—compared to animal foods, plants contain a higher proportion of dietary fiber, micronutrients, and beneficial compounds called polyphenols that are present in plants, rather than exclusively protein.

Ardisson Korat also said data from other groups is needed, as the Nurses’ Health Study surveyed primarily white females working in health care. “The data from the study tended to be very homogeneous in terms of demographic and socioeconomic composition, so it will be valuable to follow up with a study in cohorts that are more diverse. It’s a field that is still evolving,” said Ardisson Korat.

But the team’s findings so far support the recommendation that women eat most of their protein in the form of fruits, vegetables, nuts, and seeds, although they should also consume some fish and animal protein for their iron and vitamin B12 content.

“Dietary protein intake, especially plant protein, in midlife plays an important role in the promotion of healthy aging and in maintaining positive health status at older ages,” Ardisson Korat said.

Frequently using more than three strategies to stay alert while driving = obstructive sleep apnea?

RCH / AKSHAY DWARAKANATH

 Frequently using more than three strategies to stay alert while driving could be a sign of excessive sleepiness due to obstructive sleep anoea (OSA), according to a study published today (Thursday) in ERJ Open Research [1].

 

People with OSA often snore loudly, their breathing starts and stops during the night, and they may wake up several times. Around one in five people are estimated to have OSA but the majority of sufferers do not realise they have a problem. OSA causes excessive sleepiness and people with untreated OSA are at higher risk of collisions on the road.

Researchers say that asking people whether they use strategies, such as opening the window, drinking tea and coffee or turning up the radio, to stay alert on the road could help spot those with OSA who may be at a higher risk of a driving incident.

 

The study was carried out by Dr Akshay Dwarakanath and colleagues at St James’s University Hospital, Leeds, UK. He said: “Up to one fifth of collisions on the road may be caused by fatigue or sleepiness. Many OSA patients drive either for personal or for professional reasons and there is good evidence to suggest that some patients are at increased risk of collisions on the road.”

 

The research involved 119 people with OSA who were not yet receiving any treatment compared to 105 other people who did not have OSA. All the people taking part answered questions about their sleepiness in general, their sleepiness while driving, any strategies they used to stay alert while driving and any history of driving incidents, such as collisions.

 

Researchers found that people with OSA were more likely to use strategies to stay alert at the wheel compared to those without OSA. Nearly a third of people with OSA said they frequently used more than three coping strategies. None of the people who did not have OSA used more than three coping strategies.

 

Researchers also found that people with OSA who used more than three strategies felt sleepier in general, more sleepy while driving and were more likely to have experienced a crash (22.8% compared to 2.4% of OSA patients using fewer coping strategies).

 

The strategies mentioned most often by people with OSA were opening the window, drinking tea or coffee and turning up the radio. Other strategies were singing or talking to themselves, shifting positions in the seat, chewing gum or eating, stopping for a walk, fidgeting or exercising, stopping for a nap and stopping to wash their face in cold water.

 

Dr Dwarakanath said: “Doctors are often asked to make recommendations about their patient’s fitness to drive. This can be challenging as it can have major implications on a patient’s livelihood, particularly if they are a professional driver. However, there is a duty of care on doctors to discourage patients from driving if are at high risk of causing a collision.

 

“Our research suggests that untreated OSA patients often use coping strategies that could be surrogate markers of sleepiness. Asking about these strategies in the clinic may help doctors identifying patients who are at risk of driving incidents and to advise appropriately.”

 

Dr Esther Schwarz is a member of the European Respiratory Society’s group on sleep-disordered breathing, based at University Hospital Zurich in Switzerland, and was not involved in the research. She said: “Obstructive sleep apnoea is of high public health relevance due to its high prevalence, symptoms that impair quality of life and potential cardiovascular consequences. In addition to choking, fragmented sleep and unrefreshing sleep, possible symptoms include difficulty concentrating, tiredness and a tendency to fall asleep during the day. Fortunately, awareness of OSA has increased somewhat in recent years. Today, treatment recommendations are based on the different risk factors, symptom groups and cardiovascular consequences of certain OSA types. Various treatment approaches geared to different types of OSA can be offered to successfully treat the symptoms, including daytime sleepiness.”

 

Natural compounds derived from soy and other plants reduce breast cancer recurrence and improve surviva

Soy compounds called isoflavones are among the plant-derived compounds  that may significantly reduce the risk of breast cancer recurrence or death, according to a new meta-analysis co-directed by investigators from the Johns Hopkins Kimmel Cancer Center. The results were published Jan. 10 in the journal JNCI Cancer Spectrum.

Investigators in Australia, Denmark, England, Norway and the U.S. reviewed 22 published observational studies that examined the impact of  dietary intake of soybeans, lignans (compounds found in a variety of plants including seeds and nuts), cruciferous/cabbage-family vegetables, and green tea — and these substances’ phytonutrients  (natural compounds derived from plants) — on breast cancer recurrence and mortality, as well as on mortality from all causes. This included 11 studies of soy isoflavones, three of cruciferous vegetables, two of green tea, three of lignans, and three of enterolactone, which is formed in the gut when lignans are digested.  

Soy isoflavones were associated with a 26% reduced risk of breast cancer recurrence, according to a meta-analysis that included six of the studies (of  11,837 women)  reviewed by investigators. The results were most notable among post-menopausal survivors. The greatest risk reduction was seen at 60 milligrams  per day. This is equivalent to two to three servings per day, where one serving equates to a cup of soy milk, three ounces of tofu or a half-cup of cooked soybeans. However, the effect of soy consumption on risk of mortality was smaller (12%) and not statistically significant, and was seen mostly at 20-40 mg per day, or one to two servings.

Another finding, reported for the first time in a meta-analysis, relates to enterolactone, a compound metabolized from lignans. Lignans are found in a wide variety of plants, such as seeds, nuts, legumes, whole grains, fruit and vegetables. High levels are found in flaxseeds, cashew nuts, broccoli and brussels sprouts, among other sources. Enterolactone was found to reduce the risk of breast cancer-specific mortality by 28% and death from any cause by 31%, particularly in post-menopausal women (35% reduction  in death from any cause). It is not possible to calculate the effective dose of lignans in the diet from these enterolactone findings, because the gut microbiome that plays a role in metabolism of lignans varies among individuals.

“These findings were graded probable, which means there is strong research showing that they contributed to the results we are seeing,” says lead study author Diana van Die, Ph.D., of NICM Health Research Institute at Western Sydney University, Australia.

The review also found some suggestive results, which means the results are generally consistent but rarely strong enough to justify recommendations:

• Consumption  of green tea suggests an effect of reducing the risk of breast cancer recurrence by 44% in women with stage I or II breast cancer. The greatest effect was seen from consuming three to five cups per day and from five or more cups per day, as documented in two Japanese studies .

• Among those who consumed lignans prior to breast cancer diagnosis, there was a non-significant 34% risk reduction in cancer-specific mortality and 19% reduction in all causes of death in post-menopausal women. However, consumption of lignans by pre-menopausal women suggests an increased risk of mortality. This result indicates that the effects of lignans are dependent on the hormonal environment, although it was likely driven by one large study and needs further investigation. The highest intake was nine or more servings per day in the studies reviewed.

• The impact of cruciferous vegetables was inconclusive, possibly influenced by the average intake being quite low (less than a half-cup per day) in the studies reviewed.

Investigators also looked into whether consuming soy, lignans, cruciferous vegetables and green tea, or their  phytonutrients in the diet before or after breast cancer diagnosis made a difference. However, the data did not provide a concrete answer. All studies on green tea and lignans measured pre-diagnosis intake, while soy results came from studies that measured intake before and after diagnosis.

“It is critically important to stress that these studies were conducted on women who received medical and/or surgical treatment for breast cancer, and that these foods and phytonutrients should not be considered as alternatives to treatment,” says senior study author Channing Paller, M.D., director of prostate cancer clinical research and an associate professor of oncology at Johns Hopkins.

“This research highlights the need for more robust studies in this area looking at the most effective dosages of these compounds, and whether starting to consume them after diagnosis has the same effect as a lifelong dietary habit before diagnosis. This is what patients are looking for,” Paller added .