Standing more may not reduce cardiovascular disease risk, could increase circulatory disease

Standing has gained popularity among people looking to offset the harms of a sedentary lifestyle often caused by spending long days sitting in front of the computer, television or driving wheel. Standing desks have become a popular option among office workers, and in other industries like retail, workers may opt to stand instead of sit.  

However, their efforts may not produce the intended result. New University of Sydney research has shown that over the long-term, standing more compared with sitting does not improve cardiovascular health (coronary heart disease, stroke and heart failure), and could increase the risk of circulatory issues related to standing, such as varicose veins and deep vein thrombosis.

The study, published in the International Journal of Epidemiology also found that sitting for over 10 hours a day increased both cardiovascular disease and orthostatic incidence risk, reinforcing the need for greater physical activity throughout the day. The research also notes that standing more was not associated with heightened cardiovascular disease risk. 

Lead author from the Faculty of Medicine and Health and Deputy Director of the Charles Perkins Centre’s Mackenzie Wearables Research Hub, Dr Matthew Ahmadi, said there were other ways for those with a sedentary lifestyle to improve their cardiovascular health. 

“The key takeaway is that standing for too long will not offset an otherwise sedentary lifestyle and could be risky for some people in terms of circulatory health. We found that standing more does not improve cardiovascular health over the long term and increases the risk of circulatory issues,” Dr Ahmadi said.

While the researchers found that there were no health benefits gained from standing more, they cautioned against sitting for extended periods, recommending that people who are regularly sedentary or find themselves standing for long periods schedule regular movement throughout the day.

“For people who sit for long periods on a regular basis, including plenty of incidental movement throughout the day and structured exercise may be a better way to reduce the risk of cardiovascular disease,” said Professor Emmanuel Stamatakis, Director of the Mackenzie Wearables Research Hub. 

“Take regular breaks, walk around, go for a walking meeting, use the stairs, take regular breaks when driving long distances, or use that lunch hour to get away from the desk and do some movement. In Australia, we are now coming into the warmer months, so the weather is perfect for sun-safe exercise that helps you get moving,” he said. 

Professor Stamatakis and Dr Ahmadi’s research published earlier this year found that about 6 minutes of vigorous exercise or 30 minutes of moderate-to-vigorous exercise per day could help lower the risk of heart disease even in people who were highly sedentary for more than 11 hours a day. 

The study was conducted using incident heart condition and circulatory disease data taken over a period of seven to eight years from 83,013 UK adults who were free of heart disease at baseline, measured using research-grade wrist-worn wearables similar to a smartwatch.

The data used in the study was not explicitly collected on standing desk usage; instead, it measured the cardiovascular and circulatory impacts of increased standing. Standing desk use in this study likely contributes a very small fraction of total standing.

‘Brain endurance training’ promotes healthy aging

Brain endurance training (BET), a combined cognitive and exercise training method developed for athletes, boosts cognitive and physical abilities in older adults. 

According to a new study by researchers at the Universities of Birmingham, UK, and Extremadura, Spain, brain endurance training (BET) can improve attention and executive function (cognition), as well as physical endurance and resistance exercise performance. BET is a combined exercise and cognitive training method that was originally developed to increase endurance among elite athletes. 

The research has implications for healthy aging. Previous studies have shown that mental fatigue can impair both cognitive and physical performance, including poorer balance control, leading to increased risk of falls and accidents. This study, published in Psychology of Sport and Exercise, is the first to examine the benefits of BET for both cognitive and physical performance in older adults. 

Corresponding author Professor Chris Ring said: “We have shown that BET could be an effective intervention to improve cognitive and physical performance in older adults, even when fatigued. This could have significant implications for improving healthspan in this population, including reducing the risk of falls and accidents.” 

In the experiment, 24 healthy sedentary women aged between 65-78 were allocated to one of three training groups: brain endurance training (BET), exercise training, and no training (control group). The first two groups each completed three 45-minute exercise sessions per week over a period of eight weeks. Each session included 20 minutes of resistance training and 25 minutes of endurance training. While the exercise sessions were the same for each of these groups, the BET group also completed a 20-minute cognitive task prior to exercising. 

All three groups completed a series of cognitive (reaction time and colour-matching tests) and physical tests (walk, chair-stand and arm-curl tests) to assess performance at the start and end of the study. articipants in the BET group outperformed the exercise-only group in the cognitive tasks, with a 7.8% increase in cognitive performance after exercise, compared to a 4.5% increase in the exercise-only group. In terms of physical performance, the BET group achieved a 29.9% improvement, compared to 22.4% for the exercise-only group. 

“BET is an effective countermeasure against mental fatigue and its detrimental effects on performance in older adults,” added Professor Ring. “While we still need to extend our research to include larger sample sizes including both men and women, these promising initial findings show we should do more to encourage older people to engage in BET to improve brain and body activities.”  

Americans are meeting minimum needs for essential amino acids

 

 Amino acids are the building blocks for protein in food but also in human muscle. A new study characterizes amino acid intakes among Americans and another new paper examines how intakes correlate with muscle related health outcomes in older adults.

Overall, “the majority of the U.S. population is meeting the minimum dietary recommendations for both total protein and individual amino acids,” the research found. Additionally, within the range of intakes consumed by older Americans, higher essential amino acid consumption does not correlate with higher lean mass or function.

Some dietary recommendations urge older adults to consume more protein, and specific essential amino acids, in order to support muscle mass and strength. This is an important lifestage due to normal age-related declines in muscle mass.

However, associations observed in the National Health and Nutrition Examination Survey (NHANES) do not show muscle-related benefits with greater essential amino acid intake in this population.

The first study found that more than 99% of Americans over age 19 met the Estimated Average Requirements for each of the essential amino acids.

The lack of complete amino acid composition data in food composition databases has made determining population-wide amino acid intake difficult – a gap that is addressed by this new scientific contribution. This cross-sectional study of Americans characterizes intakes of each amino acid and adherence to dietary requirements for each essential amino acid.

According to first author Claire Berryman, PhD, RD with the Pennington Biomedical Research Center at Louisiana State University, “This study was the first to characterize intakes of each amino acid in the US population by gender, age, and race and ethnicity. The analysis allowed us to get a picture of current amino acid intake trends in the U.S. population. Based on our findings, Americans are meeting and exceeding minimum recommendations for all the essential amino acids.”

The second study focused on whether essential amino acid intakes in older adults correlates with lean mass and function, like grip strength. The essential amino acids are so named because the human body requires them but is unable to synthesize them. Hence, it is essential to ingest protein foods that contain them in the diet. The relationships between essential amino acid intake and body composition, muscle strength, and physical function in older U.S. adults have not been well defined until now.

This cross-sectional study evaluated associations between current usual amino acid intakes and body composition, muscle strength, and physical function in U.S. adults 65 years or older.

The study found that amino acids like leucine, lysine and sulfur-containing amino acid intakes were not associated with lean mass, muscle strength, or physical function in adults 65 years or older. However, in an unexpected finding, essential amino acid intakes — particularly lysine — were correlated cross-sectionally with measures of obesity in older U.S. women.

Associations are limited by the fact that intake in a given moment of time does not reflect a lifetime of intake which would be expected to influence body composition. Furthermore, relationships between lean mass and function and essential amino acid intakes higher than the range consumed by the population could not be evaluated.

According to author Claire Berryman, “The findings were surprising to us. We found that eating more essential amino acids in the diet was not associated with lean mass, muscle strength, or physical function in older adults and eating more of some essential amino acids was related to greater fat content in older females. These findings should be interpreted cautiously as they only represent a snapshot in time since we did not follow the participants for any length of time. However, the findings are important and should be explored further given widespread nutritional advice to consume high protein diets and the quantity of high protein foods and supplements on the market. In addition, it is important to keep in mind that consuming any macronutrient — protein, carbohydrate, or fat — in excess of calorie needs will lead to weight gain.”

Don’t rely on AI chatbots for accurate, safe drug information, patients warned

 

Patients shouldn’t rely on AI powered search engines and chatbots to always give them  accurate and safe information on drugs, conclude researchers in the journal BMJ Quality & Safety, after finding a considerable number of answers were wrong or potentially harmful.

What’s more, the complexity of the answers provided might make it difficult for patients to fully understand them without a degree level education, add the researchers.

In February 2023, search engines underwent a significant shift thanks to the introduction of AI-powered chatbots, offering the promise of enhanced search results, comprehensive answers, and a new type of interactive experience, explain the researchers.

While these chatbots can be trained on extensive datasets from the entire internet, enabling them to converse on any topic, including healthcare-related queries, they are also capable of generating disinformation and nonsensical or harmful content, they add.

Previous studies looking at the implications of these chatbots have primarily focused on the perspective of healthcare professionals rather than that of patients.  To address this, the researchers explored the readability, completeness, and accuracy of chatbot answers for queries on the top 50 most frequently prescribed drugs in the US in 2020, using Bing copilot, a search engine with AI-powered chatbot features.

To simulate patients consulting chatbots for drug information, the researchers reviewed research databases and consulted with a clinical pharmacist and doctors with expertise in pharmacology to identify the medication questions that patients most frequently ask their healthcare professionals. 

The chatbot was asked 10 questions for each of the 50 drugs, generating 500 answers in total. The questions covered what the drug was used for, how it worked, instructions for use, common side effects, and contraindications.

Readability of the answers provided by the chatbot was assessed by calculating the Flesch Reading Ease Score which estimates the educational level required to understand a particular text. 

Text that scores between 0 and 30 is considered very difficult to read, necessitating degree level education. At the other end of the scale, a score of 91–100 means the text is very easy to read and appropriate for 11 year-olds.

To assess the completeness and accuracy of chatbot answers,responses were compared with the drug information provided by a peer-reviewed and up-to-date drug information website for both healthcare professionals and patients (drugs.com)

Current scientific consensus, and likelihood and extent of possible harm if the patient followed the chatbot’s recommendations, were assessed by seven experts in medication safety, using a subset of 20 chatbot answers displaying low accuracy or completeness, or a potential risk to patient safety. 

The Agency for Healthcare Research and Quality (AHRQ) harm scales were used to rate patient safety events and the likelihood of possible harm was estimated by the experts in accordance with a validated framework.

The overall  average Flesch Reading Ease Score was just over 37, indicating that degree level education would be required of the reader. Even the highest readability of chatbot answers still required an educational level of high (secondary) school.

Overall, the highest average completeness of chatbot answers was 100%, with an average of 77%. Five of the 10 questions were answered with the highest completeness, while question 3 (What do I have to consider when taking the drug?) was answered with the lowest average completeness of only 23%.

Chatbot statements didn’t match the reference data in 126 of 484 (26%) answers, and were fully inconsistent in 16 of 484 (just over 3%). 

Evaluation of the subset of 20 answers revealed that only 54% were rated as aligning with scientific consensus. And 39% contradicted the scientific consensus, while there was no established scientific consensus for the remaining 6%. 

Possible harm resulting from a patient following the chatbot’s advice was rated as highly likely in 3% and moderately likely in 29% of these answers. And a third (34%) were judged as either unlikely or not at all likely to result in harm, if followed.

But irrespective of the likelihood of possible harm, 42% of these chatbot answers were considered to lead to moderate or mild harm, and 22% to death or severe harm. Around a third (36%) were considered to lead to no harm.

The researchers acknowledge that their study didn’t draw on real patient experiences and that prompts in different languages or from different countries may affect the quality of chatbot answers.

“In this cross-sectional study, we observed that search engines with an AI-powered chatbot produced overall complete and accurate answers to patient questions,” they write. 

“However, chatbot answers were largely difficult to read and answers repeatedly lacked information or showed inaccuracies, possibly threatening patient and medication safety,” they add.

A major drawback was the chatbot’s inability to understand the underlying intent of a patient question, they suggest.

“Despite their potential, it is still crucial for patients to consult their healthcare professionals, as chatbots may not always generate error-free information. Caution is advised in recommending AI-powered search engines until citation engines with higher accuracy rates are available,” they conclude.

 

Caffeine is a heart-healthy habit

A new paper in Rheumatology, published by Oxford University Press, finds that consuming more caffeine may improve heart health.

Vascular disease, damage of blood vessels, and their resulting consequences, heart attack and stroke, are among the leading causes of death in the general population. In patients with inflammatory rheumatic diseases, such as lupus and rheumatoid arthritis, these risks are even much higher. This is both due to the diseases themselves and some of the treatments for them, particularly cortisone derivatives.

Until now, doctors’ recommendations to reduce these vascular risks were essentially about avoiding risk factors. This included stopping inflammation, decreasing cortisone medications, as well as conventional recommendations like not smoking, reducing cholesterol, and controlling high blood pressure.

But researchers from Sapienza University of Rome, in Italy, involved in this study believe patients may be able to improve vascular health by doing something that’s actually enjoyable. The laboratory results of these investigators suggest that caffeine, present in coffee, tea, and cocoa, actively helps endothelial progenitor cells, the group of cells that helps regenerate the lining of blood vessels and are involved in vascular growth.

It’s well known that a diet rich in vitamin D (found in oily fish and eggs) and A (found in many fruits) and polyunsaturated fatty acid, and low in sodium, seems to play a role in decreasing the inflammatory burden. Scientists have wondered about caffeine as well. Besides the well-known stimulant effect on the body, caffeine also exerts an anti-inflammatory effect because it binds with the receptors expressed on the surface of immune cells. The effect of caffeine consumption on cardiovascular health has been widely investigated, with conflicting results.

Researchers here investigated 31 lupus patients without traditional cardiovascular risks factors using a seven-day food questionnaire. After a week the investigators took the patents’ blood to measure blood vessels health. They found that patients who consumed caffeine had better vascular health, as measured through endothelial cells, which form the important inner layer of blood vessels.

“The present study is an attempt to provide patients with information on the possible role of diet in controlling the disease,” said the paper’s lead author, Fulvia Ceccarelli. “It will be necessary to confirm the results through a longitudinal study, aimed at assessing the real impact of coffee consumption on the disease course.”

The paper, “Caffeine improves systemic lupus erythematosus endothelial dysfunction by promoting endothelial progenitor cells survival,” is available (on October 9th) at https://academic.oup.com/rheumatology/article-lookup/doi/10.1093/rheumatology/keae453.

 

Coffee during pregnancy safe for baby’s brain development

A University of Queensland-led study has failed to find any strong links between drinking coffee during pregnancy and neurodevelopmental difficulties in children, but researchers are advising expectant mothers to continue following medical guidelines on caffeine consumption.  

Dr Gunn-Helen Moen and PhD student Shannon D’Urso from UQ’s Institute for Molecular Bioscience (IMB) led an in-depth genetic analysis of data from tens of thousands of families in Norway.  

“Scandinavians are some of the biggest coffee consumers in the world, drinking at least 4 cups a day, with little stigma about drinking coffee during pregnancy,” Dr Moen said.

“Our study used genetic data from mothers, fathers and babies as well as questionnaires about the parents’ coffee consumption before and during pregnancy.

“The participants also answered questions about their child’s development until the age of 8, including their social, motor, and language skills.”

“Our analysis found no link between coffee consumption during pregnancy and children’s neurodevelopmental difficulties.”

The researchers said physiological changes during pregnancy prevent caffeine breaking down easily and it can cross the placenta and reach the foetus, where there are no enzymes to metabolise it.

Caffeine accumulation was thought to impact the developing foetal brain, but Dr Moen said previous observational studies couldn’t account for other environmental factors such as alcohol, cigarette smoke or poor diet.

“We used a method called Mendelian randomisation which uses genetic variants that predict coffee drinking behaviour and can separate out the effect of different factors during pregnancy,” she said.

“It mimics a randomised controlled trial without subjecting pregnant mothers and their babies to any ill effects.

“The benefit of this method is the effects of caffeine, alcohol, cigarettes and diet can be separated in the data, so we can look solely at the impact of caffeine on the pregnancy.”

The researchers use genetic analysis to understand complex traits and diseases especially in early life, with a previous study by Dr Moen showing that drinking coffee in pregnancy did not affect birth weight, risk of miscarriage or stillbirth.

They emphasise the importance of following advice from healthcare providers to limit caffeine consumption during pregnancy, as caffeine may influence other pregnancy outcomes.

The researchers are now looking to apply similar analyses to understand more about genetic and environmental causes of neurodiversity, and the effect of it from other factors on brain development during pregnancy.

The research team included international collaborators in Norway including Professor Alexandra Havdahl from PsychGen Center for Genetic Epidemiology and Mental Health, Norwegian Institute of Public Health, Oslo and England as well as IMB’s Caroline Brito Nunes, Dr Daniel Hwang and Professor David Evans. The research was conducted using data from the Norwegian Mother, Father and Child Cohort Study (MoBa).

The research was published in Psychological Medicine.å

Men and women should eat different breakfasts to lose weight

 

It’s not a bad thing if you pick a toasted bagel for breakfast, while your partner chooses eggs. In fact, according to a new study from the University of Waterloo, that difference could help you lose some weight. 

The study, which employed a mathematical model of men’s and women’s metabolisms, showed that men’s metabolisms respond better on average to a meal laden with high carbohydrates like oats and grains after fasting for several hours, while women are better served by a meal with a higher percentage of fat, such as omelettes and avocados.

“Lifestyle is a big factor in our overall health,” said Stéphanie Abo, an Applied Mathematics PhD candidate and the lead author of the study. “We live busy lives, so it’s important to understand how seemingly inconsequential decisions, such as what to have for breakfast, can affect our health and energy levels. Whether attempting to lose weight, maintain weight, or just keep up your energy, understanding your diet’s impact on your metabolism is important.” 

The study builds on an existing gap in research on sex differences in how men and women process fat. “We often have less research data on women’s bodies than on men’s bodies,” said Anita Layton, a professor of Applied Mathematics and Canada 150 Research Chair in Mathematical Biology and Medicine. 

“By building mathematical models based on the data we do have, we can test lots of hypotheses quickly and tweak experiments in ways that would be impractical with human subjects.” 

 “Since women have more body fat on average than men, you would think that they would burn less fat for energy, but they don’t,” said Layton. “The results of the model suggest that women store more fat immediately after a meal but also burn more fat during a fast.”

Going forward, the researchers hope to build more complex versions of their metabolism models and extend beyond the consideration of biological sex by incorporating an individual’s weight, age, or stage in the menstrual cycle. 

The study, Modelling sex-specific whole-body metabolic responses to feeding and fasting” appears in Computers in Biology and Medicine.