Friday, May 29, 2026

Nutrition’s role in chronic fatigue


Diet and homocysteine may influence fatigue and motivation

Peer-Reviewed Publication

Osaka Metropolitan University

Poor nutrition and fatigue 

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Dietary imbalance, low B12, and folate may correlate with high homocysteine levels and indicate fatigue and low motivation in participants. 

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Credit: Osaka Metropolitan University

With less time and more work, chronic fatigue has become a moniker of modern society. However, this not only reduces the quality of life but also constitutes as a social issue that affects work efficiency and leads to accidents. On the surface, the cause of fatigue is often attributed to not getting enough rest, but there may be another underlying issue—the lack of proper nutrition.

Taking this into account, a research group led by Professor Hiroaki Kanouchi at Osaka Metropolitan University’s Graduate School of Human Life and Ecology focused on nutritional status and water-soluble vitamin deficiencies found in unbalanced diets. The team hypothesized that a lack of folate (B9) and vitamin B12 may be related to fatigue, and centered their research around homocysteine (Hcy), a biomarker known to increase when these deficiencies are present. Blood concentrations of Hcy, folate, and vitamin B12 in approximately 600 healthy Japanese participants were measured. Participants’ fatigue and motivation were assessed using the Chalder Fatigue Scale questionnaire and Visual Analog Scale. The initial results showed that individuals with higher blood Hcy levels had lower levels of vitamin B12 and folate, regardless of sex.

The researchers then examined the relationship between homocysteine levels and fatigue separately for men and women. In their analysis, factors that may influence fatigue, such as age, sleep duration, workload, and dietary habits, were simultaneously accounted for. The results revealed higher Hcy levels were associated with greater physical fatigue in men and higher levels were associated with decreased motivation in women.

“This suggested relationship between vitamin B12, folate, and fatigue in healthy individuals may represent the first report of its kind,” said Professor Kanouchi. “Blood homocysteine levels have traditionally raised concerns in relation to cardiovascular disease, dementia, and fractures. However, our findings suggest that attention should also be paid to fatigue and motivation in the future. To prevent an increase in homocysteine levels, it is important to avoid deficiencies in vitamin B12 and folate. Maintaining a well-balanced diet on a daily basis is essential.”

The findings were published in Nutrients 

Key to managing leaky gut could lie in common compound we’re already eating

 When the intestinal lining breaks down, harmful gut bacterial antigens can slip into the bloodstream alongside nutrients. This breach in the gut’s protective barrier, known as "leaky gut," is more than a digestive issue – it’s a sign of inflammatory bowel disease (IBD) and has been increasingly linked to a number of chronic conditions. 

In a study published formally on May 28 in the journal Nature Communications, the team shares how phytic acid (or InsP6), a natural compound found in whole grains, beans, lentils, nuts, and seeds, plays an important role in maintaining the integrity of the intestinal barrier. 

“Phytic acid is something many people already consume daily, especially in plant-rich diets,” said Sujan Chatterjee, a UNLV postdoctoral fellow and lead author on the study. “What’s exciting is that it’s beyond just a dietary component; it also functions as a biologically active molecule that supports gut health.”

Eating fewer protein-rich foods may harm our physical function as we grow older

Researchers have found that consuming lower amounts of protein-rich foods may negatively affect physical functioning as people grow older, underscoring the vital function protein plays in preserving mobility and muscle strength in adulthood.  

In a large aging cohort study published in the journal Nutrients, the researchers report that regular dietary habits, particularly the consumption of protein-rich foods, can influence how well individuals move and perform daily activities later in life.  

The study was jointly conducted by an international team of researchers from the University of Sharjah in the United Arab Emirates, Roskilde University in Denmark, the University of Helsinki in Finland, Shifa Tameer-e-Millat University in Pakistan, King Saud bin Abdulaziz University for Health Sciences in Saudi Arabia, and the Medical University of Vienna in Austria.  

Led by Dr. Rizwan Qaisar, associate professor of muscle cell physiology at the University of Sharjah, the research team analyzed data from more than 38,000 adults aged fifty and above from 27 European countries. The data were drawn from the Survey of Health, Ageing, and Retirement in Europe. Participants were followed over several years, allowing researchers to compare their long-term eating habits with changes in physical strength and daily functioning.  

The results of the analysis prompted the researchers to believe that adults who frequently consumed lower amounts of protein-rich foods, such as eggs, legumes, fish, and chicken, were more likely to develop reduced muscle strength and increased difficulty in performing everyday activities over time.  

“The findings showed that individuals with consistently low protein intake were more likely to report problems with walking short distances, climbing stairs, reaching overhead, or managing routine tasks such as shopping,” said Dr. Qaisar. “These associations were particularly noticeable in older adults, and patterns differed somewhat between men and women.”  

Low protein intake and physical impairments  

Scientists link functional impairments, such as a progressive decline in the ability to perform daily tasks, including climbing stairs, rising from a chair, walking, and maintaining balance, to a consequence commonly associated with aging.  

“Simple movements such as walking, standing up, or carrying groceries require muscle strength, balance, and coordination,” explains Dr. Qaisar. “When protein intake is low over long periods, the body may struggle to maintain these systems, increasing the risk of functional decline and loss of independence.”  

The authors emphasize that these limitations not only diminish independence and quality of life but also elevate the risk of falls, hospitalization, and placement in long-term care facilities. “Functional decline is multifactorial, involving musculoskeletal deterioration, neurological changes, and nutritional deficiencies,” they note.

Importantly, the study examined real-world dietary patterns rather than supplements or restrictive diets. It highlights how everyday foods, such as milk, yogurt, eggs, legumes, fish, and poultry, may collectively support healthier aging when consumed regularly.  

Given that dietary habits can be modified, the researchers emphasize the practical implications of their findings. Identifying older adults with low protein intake could provide an opportunity for early, low-cost interventions aimed at preserving mobility, independence, and overall quality of life. 

“Functional decline and sarcopenia are major aging-related concerns. While protein intake is known to influence muscle health, its longitudinal impact on strength and physical function across age and gender remains underexplored,” they write. “We assessed whether low protein intake correlates with future onset of low handgrip strength (HGS) and physical impairments in older adults.”  

Protein intake and active and independent living  

As populations age worldwide, the authors suggest that attention to simple lifestyle factors, such as routine food choices, may help delay physical decline and support longer periods of active, independent living.  

This large, multi-country study of older European adults found that lower habitual protein intake was independently associated with higher odds of reduced handgrip strength and difficulty performing mobility-related activities.  

The association between protein intake and handgrip strength was stronger in men, whereas functional limitations, such as walking 100 meters, stooping, kneeling, extending the arm above the shoulders, and shopping for groceries, were more commonly reported among women. “These findings indicate an association between habitual protein intake and short-term changes,” the authors noted.  

Dr. Qaisar emphasized that protein is not solely important for athletes seeking to build muscle. Rather, consistent intake from common dietary sources plays a crucial role in maintaining strength and the capacity to perform everyday activities, particularly with advancing age.  

"Altogether, this study demonstrates that lower habitual protein intake is associated with a higher likelihood of short-term incident muscle weakness and functional difficulties among older European adults,” the authors conclude. “These findings suggest that habitual protein intake may play a contributory role in maintaining physical function in aging populations.”

Thursday, May 28, 2026

Natural trans fats in dairy do not raise heart disease risk

 Trans fats found naturally in dairy foods such as milk, butter and cheese do not increase the risk of heart disease or type 2 diabetes, a new study has found.  

Researchers analysed evidence from 22 studies involving thousands of people across Europe, Canada and the United States and found that natural trans fats behave very differently in the body from the industrial kind. Unlike industrial trans fats, which are strongly linked to heart disease, those found in dairy appear to pose no risk.  

The first-of-its-kind research, published in the journal Nutrition Research, will also raise consumer’s awareness of this topic and provide clarity on trans fat labelling policies which may cause confusion.  

Professor Ian Givens, one of lead authors, and from the University of Reading, said: "People hear the words 'trans fats' and assume the worst, but the trans fats in your morning milk, yogurt, butter or cheese are not the same as the ones from industrial partially hydrogenated fats. This research should give people reassurance that dairy, eaten as part of a balanced diet, is not something to worry about for your heart."  

Two types of trans fat, two different stories  

Trans fats, a type of unsaturated fat, occur naturally in the milk of animals such as cows, sheep and goats, but can also be made artificially during the production of partially hydrogenated fats. The industrial  type, can be found in some processed and fried foods, are strongly linked to heart disease.  

To test whether dairy trans fats affect heart health, the researchers looked at two types of evidence. The first was ten dietary controlled trials in which people consumed dairy foods with naturally enhanced trans fats and compared with regular dairy foods. Scientists then measured the effect on blood lipid biomarkers, which are used to determine heart disease risk. Across all ten trials, covering trans fat intakes ranging from 1.3 to 13.2 grams per day, there were no meaningful differences in blood lipid levels between trans fat-enhanced dairy foods versus regular dairy foods. 

The second type of evidence came from twelve long-term cohort studies that tracked thousands of people over many years, in some cases more than two decades, and measured the levels of dairy trans fats in their blood. None of these studies found that higher levels of dairy trans fats were linked to a greater risk of heart disease, stroke or cardiovascular death.  

Likewise,  higher levels of dairy trans fats in their blood were  not linked with type 2 diabetes risk. 

Depression may not only be a consequence, but also a cause of rheumatoid arthritis


According to researchers at Semmelweis University, not only inflammation, but also sleep disorders, depression, obesity, and smoking may sustain persistent rheumatic symptoms. In their publications in the journals Nature Reviews Rheumatology and The Lancet Rheumatology, they also proposed a model that can help identify and treat the true causes of symptoms in time.

Researchers at Semmelweis University analyzed how depression, smoking, obesity, sleep disorders, and other health problems are linked to difficult-to-treat rheumatoid arthritis.

Rheumatoid arthritis is a chronic autoimmune disease in which the immune system attacks the joints, causing pain, swelling, and stiffness. It affects tens of thousands of people in Hungary only. Most patients respond well to treatment, but 6–28 percent belong to the so-called “difficult-to-treat” group because they do not achieve lasting remission despite therapy.

According to the publications in Nature Reviews Rheumatology and The Lancet Rheumatology, these factors may not only coexist with the disease but may also help maintain it.

For example, pain and depression may reduce physical activity, increase body weight, worsen sleep and mood – all of which can feed back into pain and everyday functioning, creating a difficult-to-break “vicious cycle.” 

What does caffeine do to our sleep?

 Evening coffee has sparked controversy for years. Some people fall asleep without difficulty, while others toss and turn for half the night. However, a growing body of research suggests that the question of whether “coffee makes it harder to fall asleep” may be too simplistic. What appears to matter far more is what happens in the brain during sleep. 

Scientists studying the effects of caffeine on sleep are increasingly turning to EEG, or electroencephalography — a method used to record the brain’s electrical activity. Thanks to EEG, it is possible to observe not only sleep duration or moments of awakening, but also the biological quality of sleep itself. 

– EEG allows us to see not only whether a person is sleeping, but also how the brain is sleeping. Classical sleep assessment assesses sleep duration and its stages, whereas quantitative EEG analysis reveals more subtle changes, such as reduced slow-wave activity, which is an important marker of sleep depth and its restorative character, explains Prof. Donata Kurpas from the Department of Nursing, Wroclaw Medical University. 

Slow waves are one of the key components of deep sleep — the phase responsible for bodily regeneration, restoration of energy resources, and proper brain function. 

Caffeine may cause “shallow” sleep 

Research shows that the effects of caffeine do not always manifest as shorter sleep or difficulty falling asleep. Much more often, the changes concern the quality of nighttime rest. 

– Caffeine may shorten sleep or make it more difficult to fall asleep; however, even when sleep duration appears normal, it may reduce slow-wave activity and shift the EEG pattern toward a more ‘wakeful’ brain, says Prof. Kurpas. 

This means the body may spend eight hours in bed, but the brain may fail to fully regenerate. People are often unaware of this. 

– The subjective feeling of having slept well does not always correspond to what we observe in neurophysiological recordings. A person may fall asleep without major difficulty and not remember awakenings, while the brain may display fewer features of deep sleep, the expert adds. 

Why does coffee affect everyone differently? 

One of the most interesting conclusions emerging from research is the enormous individual variability in response to caffeine. Genetics, metabolic rate, age, stress levels, and chronic fatigue all play a role. 

For some individuals, even coffee consumed in the morning may be problematic. 

– It is not only about coffee consumed just before bedtime. For some people, the total amount of caffeine consumed during the day and whether the body has enough time to metabolize it before nightfall may also be important, Prof. Kurpas emphasizes. 

This is particularly important information for people engaged in intellectual work, athletes, and anyone who regularly uses caffeine to improve performance and concentration. 

Energy is borrowed from the body 

Caffeine improves alertness and reduces the sensation of fatigue, but experts point out that its effects may sometimes resemble “borrowing energy” at the expense of nighttime regeneration. 

– If caffeine helps a person function during the day while simultaneously worsening the quality of nighttime recovery, a vicious circle may develop: greater fatigue, greater need for stimulation, and poorer sleep, says Prof. Kurpas. 

For this reason, modern sleep research is increasingly moving away from simple questions about sleep duration and focusing instead on how the brain functions during nighttime rest. 

– Caffeine is neither ‘good’ nor ‘bad’. It is a biologically active substance whose effects depend on dose, time of day, age, lifestyle, sleep quality, stress burden, and individual sensitivity, the expert concludes.

Plant-forward and low-insulinemic diets = reduced weight gain during menopause

 

, long-term study finds

Peer-Reviewed Publication

National University of Singapore, Yong Loo Lin School of Medicine

A large long-term study of nearly 40,000 women has found that women who eat more plant-based, low-insulinemic foods may gain less weight and have a much lower risk of developing obesity during the years around menopause. A low-insulinemic diet refers to a diet that is less likely to cause repeated spikes in insulin, a hormone that helps regulate blood sugar and fat storage.

 

Menopause is a major life stage marked by hormonal and metabolic changes. During this period, many women are more likely to experience weight gain and face a higher risk of obesity, type 2 diabetes, and cardiovascular disease. While healthy eating is known to support weight management, there has been limited evidence on which specific diets may work best for women during this transition.

 

To address this gap, researchers from the NUS–Harvard Women’s Health Initiative (NUSHINE) conducted one of the first long-term studies to comprehensively compare 11 dietary patterns in women going through menopause. The study was co-led by Chair Professor Zhang Cuilin, Department of Obstetrics and Gynaecology, and Director of the Global Centre for Asian Women’s Health (GloW) at the NUS Yong Loo Lin School of Medicine (NUS Medicine), together with Harvard T.H. Chan School of Public Health’s Professor Frank B. Hu, Chair of the Department of Nutrition, and Dr Xia Tong, postdoctoral fellow , and other collaborators.

 

Published in JAMA Network Open, the study analysed data from 38,283 women enrolled in the Nurses’ Health Study II from 1989 to 2019, focusing on approximately 12 years around menopause. In the study, 90 per cent of the participants are Caucasian, with future studies focusing on more diverse populations, including Asians. Participants’ diets were assessed once every four years using validated food frequency questionnaires, and their body weight was tracked across six two-year intervals. This allowed the researchers to study how different eating habits were linked to weight changes during the menopausal transition. In total, the study compared 11 dietary patterns, along with ultra-processed food intake, within the same group of women.

 

Over the follow-up period, women gained an average of 0.80kg per year, while 5,214 developed obesity, based on over 340,000 combined years of follow-up across all participants. Among all the diets studied, the Planetary Health Diet Index, which focuses on plant-based foods such as nuts, legumes, whole grains, fruits, and vegetables, was most strongly linked to a lower risk of obesity. Women who followed this diet most closely had a 54 per cent lower risk of developing obesity compared with those who followed it the least.

 

Another dietary pattern, known as the reverse Empirical Dietary Index for Hyperinsulinemia, was linked to the greatest reduction in yearly weight gain. This diet is considered to have lower insulinemic potential, meaning it is less likely to place repeated high insulin demands on the body. Women who followed this pattern gained 0.28kg less per year than those whose diets had higher insulinemic potential. This pattern was marked by lower intakes of red and processed meats, French fries, potatoes, and sodium.

 

In contrast, diets higher in ultra-processed foods, red and processed meats, sodium, potatoes, and French fries were linked to greater weight gain and a higher risk of obesity. A diet high in red and processed meats, fries, and sodium was associated with nearly double the risk of obesity. Overall, the findings point to a practical message: eating more nuts, legumes, fruits, vegetables, and whole grains, while cutting back on red and processed meats, salty foods, and fried potatoes, may help women manage their weight more healthily during menopause.

 

“These findings send a hopeful and practical message to women navigating one of the most challenging metabolic transitions in their lives. Adopting a plant-forward, low-insulinemic diet does not require drastic changes — it can be as simple as eating more whole grains, nuts, legumes, and vegetables, and reducing reliance on processed and high-sodium foods. If incorporated into routine midlife care, this dietary guidance could meaningfully reduce the long-term burden of obesity and cardiometabolic disease in women,” said Prof Zhang.

 

“Our findings are especially timely as obesity and cardiometabolic diseases continue to rise among midlife women worldwide,” added Prof Hu. “Incorporating evidence-based dietary counselling into routine midlife healthcare may help women protect their long-term health and reduce the risk of obesity-related chronic diseases.”

 

Future studies should examine these associations in more diverse populations, including Asian women, and explore whether targeted dietary interventions during menopause can improve cardiometabolic health. The NUS–Harvard collaboration through NUSHINE is well-positioned to address these questions and generate evidence that could inform dietary guidelines and clinical practice for women in midlife.