Sports-related sudden cardiac arrest is rare in older adults

 

FINDINGS

The annual incidence of sports-related sudden cardiac arrest in older adults is rare: 2 to 3 cases per 100,000 people.

Of the 4,078 total sudden cardiac arrest cases studied in people 65 and older, 77 (1.9%) occurred during or following an exercise activity, such as cycling, gym workout, running, or playing golf or tennis. Most of the cardiac arrests occurred in men (91%). 

Investigators also analyzed medical records, which were available for 47 people with sports-related cardiac arrest and 3,162 for people with non-sports-related cardiac arrest. This analysis revealed that people who experienced sudden cardiac arrest during or shortly after exercise were more likely to have fewer cardiovascular risk factors and other health issues than people who did not experience exercise-related sudden cardiac arrest. 

People who experienced sports-related cardiac arrest were also more likely to experience it in a public location, which contributed to being four times more likely to survive than those who experienced a non-sports-related cardiac arrest. 

BACKGROUND

A sudden cardiac arrest occurs when an electrical malfunction causes a person’s heart to stop beating. This is an extremely dangerous event, with most people dying within minutes. The good news is that in recent years, the occurrence of sudden cardiac arrest has decreased among people of working age. But for older people, the rates of sudden cardiac arrest have increased. 

Exercise is one of the most heart-healthy habits to engage in. In rare cases, however, it can trigger an irregular heart rhythm that leads to sudden cardiac arrest. 

METHODS

Investigators analyzed sudden cardiac arrests that have occurred among people age 65 and older in Portland, Oregon, and Ventura County, California. To do this, they reviewed data collected as part of two prospective studies: The Oregon Sudden Unexpected Death Study, which has been ongoing since 2002, and the Ventura Prediction of Sudden Death in Multi-ethnic Communities study, which has been ongoing since 2015. The data excluded people who experienced sudden cardiac arrest while hospitalized and people for whom resuscitation was not attempted. 

People who died from sudden cardiac arrest during sports activity or within one hour of the activity were categorized as having sports-related sudden cardiac arrest. 

IMPACT

The findings reveal that even though sports activity is steadily rising in older adults, sudden cardiac arrest triggered by sports activity is uncommon. Furthermore, people who have sudden cardiac arrest with exercise tend to have fewer comorbidities and cardiovascular risk factors than people who have sudden cardiac arrest not triggered by exercise. Taken together, the benefits of sports activity likely outweigh the risk of associated sudden cardiac arrest risk, the authors conclude. 

“The annual incidence of sports-related sudden cardiac arrest among older adults is extremely rare,” said Sumeet S. Chugh, MD, the Pauline and Harold Price Chair in Cardiac Electrophysiology Research, director of the Heart Rhythm Center in the Smidt Heart Institute at Cedars-Sinai, and senior author of the study. “This means older people who regularly participate in sports should continue. Those who develop new symptoms should consult their physician. Those who want to start should be encouraged to do so, but only after consulting their physician and obtaining an exercise prescription.”

The research was published in the peer-reviewed journal JACC: Clinical Electrophysiology.

Mixed tree nuts: positive impact on cardiovascular risk factors and increase serotonin

 

In a paper[1] published online this week in the journal, Nutrients, researchers found that consuming mixed tree nuts (almonds, Brazil nuts, cashews, hazelnuts, macadamias, pecans, pine nuts, pistachios and walnuts) had a positive effect on the metabolism of the essential amino acid, tryptophan, in overweight and obese individuals. Specifically, there was an increase in both cardioprotective tryptophan metabolites and in the neurotransmitter, serotonin.

 

In a previous study[2], researchers at UCLA demonstrated that consuming 1.5 ounces of tree nuts per day (versus pretzels) during 24 weeks of weight loss and weight maintenance, resulted in weight loss, increased satiety, decreased diastolic blood pressure and decreased heart rate. Tryptophan (found in tree nuts) has been indicated as an important factor in cardiovascular disease (CVD). It is metabolized in the gut, producing many bioactive metabolites that are important in immune regulation affecting chronic diseases such as diabetes and CVD. The current study looked at whether tree nut snacks, as part of a hypocaloric diet, could modify the gut microbiome, resulting in increased levels of cardio-protective tryptophan microbial metabolites.

 

Plasma and stool samples were collected from 95 overweight or obese participants and were evaluated in the current study for tryptophan metabolites and for gut microbiota. “We’ve known for a long time that tree nuts can help decrease CVD risk, and these findings provide some possible explanations,”

. “We discovered some new associations between tryptophan metabolites and blood pressure, heart rate, and satiety in overweight/obese subjects, suggesting a broader impact of tryptophan metabolism in overall health, including cardiovascular health.”

 

Another interesting finding was the significant increase in blood serotonin levels (60.9% and 82.2% increase from baseline at week 12 and 24, respectively) in both the weight loss and weight maintenance phases, in the those who consumed mixed tree nuts. “This is the first time we’ve seen mixed tree nut consumption associated with an increase in serotonin levels in the body,” explained Dr. Li. “While more research is needed, this is exciting since serotonin can have an important impact on mood and overall mental health.”

 

Research has shown that people get about 25% of their calories each day from snacks and a large proportion come from desserts, sugar-sweetened beverages, sweets and salty snacks.[3] “Replacing just one of those snacks with 1.5 ounces of tree nuts may help improve overall health and reduce the risk for various chronic diseases,” stated Maureen Ternus, M.S., R.D.N, Executive Director of the International Tree Nut Council Nutrition Research & Education Foundation.

Healthy lifestyle linked to slower memory decline in older adults

A healthy lifestyle, in particular a healthy diet, is associated with slower memory decline, finds a decade-long study of older adults in China, published today in The BMJ.

Even for carriers of the apolipoprotein E (APOE) gene - the strongest known risk factor for Alzheimer’s disease and related dementias - a healthy lifestyle was found to slow memory loss.

Memory continuously declines as people age, but evidence from existing studies is insufficient to assess the effect of a healthy lifestyle on memory in later life. And given the many possible causes of memory decline, a combination of healthy behaviours might be needed for an optimal effect.

To explore this further, researchers analysed data from 29,000 adults aged at least 60 years (average age 72; 49% women) with normal cognitive function who were part of the China Cognition and Aging Study.

At the start of the study in 2009, memory function was measured using the Auditory Verbal Learning test (AVLT) and participants were tested for the APOE gene (20% were found to be carriers). Follow-up assessments were then conducted over the next 10 years in 2012, 2014, 2016, and 2019.

A healthy lifestyle score combining six factors was then calculated: healthy diet, regular exercise, active social contact (eg. seeing friends and family), cognitive activity (eg. writing, reading, playing mahjong), non-smoking, and never drinking alcohol. 

Based on their score, ranging from 0 to 6, participants were put into favourable (4 to 6 healthy factors), average (2 to 3 healthy factors), or unfavourable (0 to 1 healthy factors) lifestyle groups and into APOE carrier and non-carrier groups.

After accounting for a range of other health, economic and social factors, the researchers found that each individual healthy behaviour was associated with a slower than average decline in memory over 10 years.

A healthy diet had the strongest effect on slowing memory decline, followed by cognitive activity and then physical exercise.

Compared with the group that had unfavourable lifestyles, memory decline in the favourable lifestyle group was 0.28 points slower over 10 years based on a standardised score (z score) of the AVLT, and memory decline in the average lifestyle group was 0.16 points slower.

Participants with the APOE gene with favourable and average lifestyles also experienced a slower rate of memory decline than those with an unfavourable lifestyle (0.027 and 0.014 points per year slower, respectively).

What’s more, those with favourable or average lifestyles were almost 90% and almost 30% less likely to develop dementia or mild cognitive impairment relative to those with an unfavourable lifestyle, and the APOE group had similar results. 

This is an observational study so can’t establish cause and the researchers acknowledge some limitations, such as the potential for measurement errors due to self-reporting of lifestyle factors, and the possibility of selection bias, as some participants did not return for follow-up evaluations.

But this was a large study with a long follow-up period, allowing for evaluation of individual lifestyle factors on memory function over time. And findings remained significant after further analyses, suggesting that they are robust.

As such, the researchers say their results provide strong evidence that adherence to a healthy lifestyle with a combination of positive behaviours is associated with a slower rate of memory decline, even for people who are genetically susceptible to memory decline. 

They suggest further research could focus on the effects of a healthy lifestyle on memory decline across the lifespan, acknowledging that memory problems can also affect younger people, not included in this study. “These results might offer important information for public health initiatives to protect older adults against memory decline,” they conclude.

“Prevention is important, given the absence of effective treatments for Alzheimer’s disease and related dementias,” say researchers in a linked editorial.

However, they point out that these results do not help to determine which among the six health behaviours included in the score (or specific combination) is the best target for dementia prevention, or when in the life course to focus prevention efforts. Further insight is also needed to determine whether the differences in memory decline observed in this study are clinically meaningful, they add.

They suggest a similar approach that led to a substantial reduction in cardiovascular disease should be taken with dementia prevention, “identifying not only the factors that matter most but also the threshold at which they matter, and the age when intervention is likely to be most effective.”

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JOURNAL

The BMJ

DOI

10.1136/bmj-2022-072691 

Lifelong marriage lowers risk of dementia

If you are married continuously for many years in mid-life, you have a lower risk of developing dementia in old age. This has been confirmed by a recently published study based on data from HUNT Study health surveys in Nord-Trøndelag.

“Being married can have an influence on risk factors for dementia,” says Vegard Skirbekk at the Norwegian Institute of Public Health (NIPH/FHI).

The researchers looked at different types of marital status in people over a period of 24 years – from the age of 44 until 68 – and investigated whether this status was related to a clinical diagnosis of dementia or mild cognitive impairment (MCI) after the age of 70.

The results show that the group that was continuously married throughout the period had the lowest incidence of dementia.

The highest incidence was found in divorced and single people.

Children reduce risk

Asta Håberg is a doctor at St. Olav's Hospital and a professor at the Norwegian University of Science and Technology (NTNU), as well as a researcher at NIPH/FHI. She says the results of the survey contained surprises.

“Exactly what causes dementia is a mystery. This survey indicates that being married and a lower risk of dementia are linked, but we don't know why,” says Håberg.

“One theory has been that people who are married live healthier lives, and that this explains differences in the risk of various diseases. In this survey, we found no support for health differences between married and unmarried people that would explain the difference in dementia risk.”

In the HUNT survey, approximately 150 000 people living in the former country of Nord-Trøndelag have given consent for their health information to be made available for research. The researchers used this data to check the incidence of dementia against health factors such as smoking, high blood pressure, obesity, physical inactivity, diabetes, psychological problems and having close friends.

“We thought that these factors would mean something, but they didn’t explain anything,” says Håberg.

However, the researchers found that having children had significance and reduced the risk of dementia by 60 per cent among the unmarried people in the study.

“Some people have theorized that if you have children, you stay more cognitively engaged. For example, you have to deal with people and participate in activities that you wouldn’t otherwise have to. This stimulates your brain so that it possibly works better. That way you build up a kind of cognitive reserve,” says Håberg.

Still a lot of unused data

This "reserve" in the brain is not structural. It doesn’t show up on an MRI scan or by opening the brain and looking inside. It is part of the "mystery of dementia". But Håberg hopes to be able to uncover some of the mystery through this study.

“We don’t know whether it’s being married or having children that protects against dementia, or if it’s a case of pre-selection, for example. This would mean that people who have a lower probability of developing dementia also have a higher probability of finding a partner and having children. But the fact that we have the HUNT Study means that we have a lot of data available that we haven’t yet used to investigate this further,” Håberg says.

As a doctor, she is not convinced that dementia is an inevitable consequence of aging.

“It’s common to think that 'if you live long enough, sooner or later you’ll develop dementia'. I'm not so sure I agree with that, given this theory that we may have cognitive reserves,” she said. "It could be that certain conditions might help to build up such reserves, which means that you start with more connections in the brain. For example, we’ve observed that education is a factor, and that the more education you have, the better the "reserves" that you build up."

And yet, when a highly educated person gets Alzheimer's, the disease progresses just as quickly as for anyone else. The reserves thus have a delaying effect – but only until the disease strikes.

Make it easier to have children

The study results are part of the research project REFAWOR (Cognitive reserve work and family) funded by the NIH in the USA, which is part of the programme "Changing lives, changing brains" under the auspices of the Norwegian Institute of Public Health.

REFAWOR has a budget of almost three million euros and aims to study how changes in living and working conditions affect the risk of Alzheimer's, dementia and cognitive impairment in older people. These diseases are expected to triple by 2050.

The researchers are now taking a closer look at the significance of having children for dementia risk, the types of work people have and how retirement age can affect the risk.

Dementia is a collective term for various diseases and injuries in the brain. Memory weakens, and the ability to think logically is affected. Eventually it becomes difficult to manage on your own and carry out everyday activities. No medical treatment for dementia is currently available.

“We’ve dreamt of finding a medicine for dementia for a long time, but we haven’t yet succeeded. So we’re looking at social determinants. What can society do to reduce the risk? The state could facilitate having children, for example,” says Håberg.

Genes can make us more susceptible

One of the next steps is to look at genetic connections, says Skirbekk.

“We know that certain genes increase the risk of dementia, but people with these genes can still live to be 90 years old without experiencing cognitive problems,” he says.

“You could say that the increased risk inherent in the genes can be regarded as a vulnerability, where having a stable family life might possibly reduce this vulnerability.

He emphasizes that this study says nothing about the biological mechanisms behind dementia.

“But it shows that being married can have an influence on risk factors. You become more cognitively active, you cope better with adversity and are less subject to stress. The partner represents a security that provides a buffer.”

The study does not consider whether any difference exists between being an unmarried versus a married couple. Less than one per cent of unmarried people in the survey were cohabiting with a partner.

“There are very few cohabitants in this age group in HUNT,” says Håberg.

Reference:

Vegard Skirbekk, Catharine E. Bowen, Asta Håberg, Steinar Krogstad et al: Marital Histories and Associations With Later-Life Dementia and Mild Cognitive Impairment Risk in the HUNT4 70+ Study in Norway, Journal of Aging and Health.

https://doi.org/10.1177/08982643221131

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JOURNAL

Journal of Aging and Health

DOI

10.1177/08982643221131926 

More steps, moderate physical activity cuts dementia, cognitive impairment risk

Peer-Reviewed Publication

 

IMAGE: ANDREA LACROIX, PH.D., M.P.H., DISTINGUISHED PROFESSOR AT THE UC SAN DIEGO HERBERT WERTHEIM SCHOOL OF PUBLIC HEALTH AND HUMAN LONGEVITY SCIENCE view more 

CREDIT: UNIVERSITY OF CALIFORNIA SAN DIEGO

Senior women were less likely to develop mild cognitive impairment or dementia if they did more daily walking and moderate-to-vigorous physical activity, according to a new study led by the Herbert Wertheim School of Public Health and Human Longevity Science at University of California San Diego.

In the Jan. 25, 2023 online edition of Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, the team reported that, among women aged 65 or older, each additional 31 minutes per day of moderate-to-vigorous physical activity was associated with a 21 percent lower risk of developing mild cognitive impairment or dementia. Risk was also 33 percent lower with each additional 1,865 daily steps.

“Given that the onset of dementia begins 20 years or more before symptoms show, the early intervention for delaying or preventing cognitive decline and dementia among older adults is essential,” said senior author Andrea LaCroix, Ph.D., M.P.H., Distinguished Professor at the Herbert Wertheim School of Public Health and Human Longevity Science at UC San Diego.

While there are several types, dementias are a debilitating neurological condition that can cause loss of memory, the ability to think, problem solve or reason. Mild cognitive impairment is an early stage of memory loss or thinking problems that is not as severe as dementias.

According to the United States Department of Health and Human Services, dementia affects more than 5 million people in this country. That number is expected to double by 2050. 

More women live with and are at higher risk of developing dementia than men.

“Physical activity has been identified as one of the three most promising ways to reduce risk of dementia and Alzheimer’s disease. Prevention is important because once dementia is diagnosed, it is very difficult to slow or reverse. There is no cure,” said LaCroix.

However, because few large studies have examined device measures of movement and sitting in relation to mild cognitive impairment and dementia, much of the published research on the associations of physical activity and sedentary behavior with cognitive decline and dementia is based on self-reported measures, said first author, Steven Nguyen, Ph.D., M.P.H., postdoctoral scholar at the Herbert Wertheim School of Public Health.

For this study, the researchers sampled data from 1,277 women as part of two Women’s Health Initiative (WHI) ancillary studies — the WHI Memory Study (WHIMS) and the Objective Physical Activity and Cardiovascular Health (OPACH) study. The women wore research-grade accelerometers and went about their daily activities for up to seven days to obtain accurate measures of physical activity and sitting.

The activity trackers showed the women averaged 3,216 steps, 276 minutes in light physical activities, 45.5 minutes of moderate-to-vigorous physical activity and 10.5 hours of sitting per day. Examples of light physical activity could include housework, gardening or walking. Moderate-to-vigorous physical activity could include brisk walking.

The study findings also showed that higher amounts of sitting and prolonged sitting were not associated with higher risk of mild cognitive impairment or dementia.

Together, this information has clinical and public health importance as there is little published information on the amount and intensity of physical activity needed for a lower dementia risk, said Nguyen.

“Older adults can be encouraged to increase movement of at least moderate intensity and take more steps each day for a lower risk of mild cognitive impairment and dementia,” said Nguyen.

“The findings for steps per day are particularly noteworthy because steps are recorded by a variety of wearable devices increasingly worn by individuals and could be readily adopted.”

The authors said further research is needed among large diverse populations that include men.

Co-authors include: John Bellettiere, UC San Diego; Kathleen M. Hayden and Stephen R. Rapp, Wake Forest University School of Medicine; Chongzhi Di, Fred Hutchinson Cancer Center; Priya Palta, Columbia University Irving Medical Center; Marcia L. Stefanick, Stanford University School of Medicine; JoAnn E. Manson, Harvard Medical School; and Michael J. LaMonte, University at Buffalo – SUNY.

This research was funded, in part, by the National Institute on Aging (P01 AG052352, 5T32AG058529-03) and the National Heart, Lung, and Blood Institute (R01 HL105065). The Women’s Health Initiative was funded by the National Heart, Lung, and Blood Institute (75N92021D00001, 75N92021D00002, 75N92021D00003, 75N92021D00004, 75N92021D00005).

Adding just a small handful of walnuts can have dietary benefits for the whole family

 

 

IMAGE: SNACKING ON WALNUTS. view more 

CREDIT: CHRIS YASKO, PHOTOGRAPHER.

A new study1 from researchers at Indiana University School of Public Health-Bloomington has found that adding one ounce of walnuts (or one handful) to the diet of children and adults who do not normally eat nuts improves diet quality and intake of some under-consumed nutrients of public health importance.

Consistent evidence shows that walnuts as a snack or within a meal can provide good nutrition and be part of a healthy diet for life.1,2

“While nut consumption is already promoted in the Dietary Guidelines for Americans as part of a healthy dietary pattern, consumers are often not eating enough alongside whole grains, fruit and vegetables,” says Dr. Thiagarajah, lead researcher on the study and Senior Lecturer of Nutrition at Indiana University School of Public Health-Bloomington.

“Underconsumption of nutritious foods like walnuts as part of a balanced diet can result in nutrient inadequacies. When added in the diet, walnuts lead to small nutrition wins for the whole family,” she adds.

For parents and guardians, ensuring children and adolescents are getting all the nutrients they need can be challenging.3 This is one of the few studies looking at the typical diet of both children and adults and simulating how the simple addition of walnuts to the diet could help achieve better nutritional status. Incorporating walnuts into snacks and meals may be an easy option for adults and children to consider as part of their diet.   

Study Overview

Advanced statistical modeling techniques were used to see what would happen when one ounce of walnuts was added to the typical daily diet of nearly 8,000 Americans who do not currently eat nuts. 

Participant health and dietary information were obtained from The National Health and Nutrition Examination Survey (NHANES), which is a nationally representative, cross-sectional survey of people living in the United States. Information was analyzed by age group (4–8 years, 9–13 years, 14–18 years, 19–50 years, 51–70 years, 71 years and older) and gender.

“We primarily wanted to see how adding a handful of walnuts to the typical U.S. diet could change intakes in nutrients of public health concern identified by the 2020–2025 U.S. Dietary Guidelines for Americans, including potassium, dietary fiber, and magnesium,” explains Dr. Thiagarajah.

Researchers then evaluated diet quality with and without the added one ounce of walnuts using the 2015 Healthy Eating Index (HEI-2015).

Results At A Glance

Adding one ounce of walnuts to the typical diets of Americans resulted in the following outcomes listed in Table 1.

Table 1. Summary of the nutrient impact of adding one ounce of walnuts to typical American diet

Outcome	Result
Healthy Eating Index (e.g., Diet Quality)	Significantly improved the diet quality for all ages and genders.  Improvements were seen for the seafood and plant protein category (e.g., more seafood and plant protein), as well as the ratio of unsaturated to saturated fats (e.g., less saturated fat).
Nutrients of Public Health Importance from the 2020 Dietary Guidelines for Americans	Significantly improved fiber intake across all age and gender categories. Increased the percentage of adults above the recommended daily intake for potassium. A similar trend was observed among children and adolescents (4–18 years). Reduced the percentage of adults, children, and adolescents with intakes below the daily needs for magnesium and folate.
Other Nutrients	Reductions in copper and zinc inadequacy for most age and gender groups.

 

“This was not an intervention or feeding study, but the modeling done as part of this research is highly important as it allows us to evaluate broad dietary implications for the general public which could have meaningful impacts to overall health,” notes Dr. Thiagarajah.

 

Limitations of this study include the fact that self-reported 24-hour dietary recall data were used to conduct the modeling in this study and are subject to measurement error due to large day-to-day variations in food intake.

Additionally, this study can only be used to explain how adding walnuts to the diet of no-nut consumers may be impacted (n=7,757). No nut consumers tended to be younger, Hispanic or black, have an annual household income of less than $20,000. 

While this modeling study demonstrates potential positive nutritional impact with walnut consumption, further observational studies or well-designed randomized clinical trials are needed to confirm these results. 

A simple strategy such as adding one ounce of walnuts to a daily eating pattern can be a potential solution to improve diet quality for people of all ages. This modeling study clearly demonstrates that small dietary changes with nutrient-dense foods like walnuts may have significant benefits on nutrient intake and diet quality.

References: 

1. Spence LA, Henschel B, Li R, Tekwe CD, Thiagarajah K. Adding walnuts to the usual diet can improve diet quality in the United States: Diet modeling study based on NHANES 2015–2018. Nutrients. 2023;15(2):258.
2. Yi SY, et al. Association of nut consumption with CVD risk factors in young to middle-aged adults: The Coronary Artery Risk Development in Young Adults (CARDIA) study. Nutrition, Metabolism and Cardiovascular Diseases. 2022;32(10):2321-2329.
3. U.S. Department of Agriculture and U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2020-2025.  9th Edition. December 2020. Available at DietaryGuidelines.gov.

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Mid-life moderate + vigorous physical activity quota associated with brain power

 

The amount of time spent in moderate and vigorous physical activity every day is linked to mid-life brain power, indicates research published online in the Journal of Epidemiology & Community Health.

This intensity level seems to be the best for working memory and mental processes, such as planning and organisation, and replacing it with just 6-7 minutes of light intensity activity or sedentary behaviour every day is associated with poorer cognitive performance, the findings indicate.

Previously published studies link daily moderate and vigorous physical activity, or MVPA for short, to health, but few have included time spent asleep, which makes up the largest component of any 24 hour period, say the researchers.

They therefore adopted a compositional approach to find out if MVPA relative to all other daily movement behaviours might be best for mid-life cognitive performance.

They drew on participants in the 1970 British Cohort Study, comprising people born across England, Scotland, and Wales in 1970 whose health was tracked throughout childhood and adulthood.

In 2016–18, 8581 participants had reached the ages of 46-47, at which point they were asked to fill in detailed health, background, and lifestyle questionnaires, and to wear an activity tracker for up to 7 days and for at least 10 consecutive hours a day.

They took various cognitive tests for verbal memory (immediate and delayed word recall tasks) and executive function (verbal fluency and processing speed/accuracy). 

Scores for each test were summed to produce an overall global score for memory and executive function.

Among those who agreed to wear an activity tracker, 2959 participants were excluded due to device error, insufficient wear time, or failing to fully complete the questionnaires. 

The final analysis included 4481 participants, just over half of whom (52%) were women. Two thirds (66%) were married and 43% were educated up to the age of 18. Over two thirds (68%) were occasional or non-risky drinkers and half had never smoked.

Analysis of the activity tracker data showed that participants clocked up an average of 51 minutes of MVPA, 5 hours 42 minutes of light intensity physical activity, 9 hours 16 minutes of sedentary behaviours, and 8 hours 11 minutes of sleep over a 24 hour period.

Time spent in MVPA relative to other types of behaviour was positively associated with cognitive performance after adjusting for educational attainment and workplace physical activity. But additional adjustment for health issues weakened these associations. 

Sedentary behaviour relative to sleep and light physical intensity activity was also positively associated with cognitive performance: a trend which likely reflects greater engagement in cognitively stimulating activities such as reading or working rather than any apparent benefit from watching TV, note the researchers.

The associations were stronger for executive function than they were for memory.

Compared with the average across the sample, participants in the upper half of cognitive performance scores spent more time in MVPA and sedentary behaviours and less time sleeping, while the lowest 25% of scorers clocked up the most light intensity physical activity.

To better understand the joint associations of movement with cognition, the researchers reallocated time from one component to another, minute by minute, to estimate what impact this might have on global cognitive performance scores.

This revealed increases in scores after MVPA theoretically displaced other activities.

Individuals’ cognition showed a 1.31% improvement in cognition ranking compared to the sample average improvement after as little as 9 minutes of sedentary activities with more vigorous activities - a positive trend which became far more substantive with much greater reductions in sedentary activities. 

Similarly, there was a 1.27% improvement from replacing gentle activities or 1.2% from replacing 7 minutes of sleep. Such improvements showed further improvement with greater exchanges of time.

Sedentary behaviour was also favourable for cognition score, but only after substituting it for 37 minutes of light intensity physical activity or 56 minutes of sleep.

Participants began theoretically declining in their cognition ranking within the study sample by 1-2% after just 8 minutes of more vigorous activity was replaced by sedentary activities. Ranking continued to decline with greater declines in MVPA.

Similarly, replacing vigorous activities with 6 minutes of light intensity physical activity or 7 minutes of sleep, was linked with similar falls of 1-2% in cognition ranking, again worsening for greater losses of MVPA.  

The activity trackers can only capture time spent in bed rather than sleep duration or quality, which might help to explain the association with sleep, say the researchers.

“MVPA is typically the smallest proportion of the day in real terms, and the most difficult intensity to acquire. Perhaps partly for this reason, loss of any MVPA time whatsoever appeared detrimental, even within this relatively active cohort,” they explain.

This is an observational study, and as such, can’t establish cause. And the researchers highlight various caveats: activity tracker measures can’t provide context for each component of movement. And despite a large sample size, people of colour were underrepresented, limiting the generalisability of the findings. 

Nevertheless, they conclude: “This robust method corroborates a critical role for MVPA in supporting cognition, and efforts should be made to bolster this component of daily movement.”

 

Solo exercise is good for older brains, but exercise with others is even better

 Exercise is beneficial in obvious ways like getting a leaner and stronger body, yet its benefits can also improve the brain, including in older adults. Socializing can also have cognitive benefits. Now, a study published in Archives of Gerontology and Geriatrics, not only found cognitive benefits of regular exercise among older people, it found even greater benefits when exercise is done with others.

The global number of dementia patients is expected to surpass 150 million by 2050. As a result, interest is rising in manageable activities, such as exercise and socializing, which may reduce the risk of age-related cognitive disorders.

"Exercise is manageable for many older people, and we saw cognitive benefits from it compared with those who don't exercise," says study senior author Professor Tomohiro Okura from the University of Tsukuba. "But it's even more noteworthy that we found exercise's benefits rise—14.1 percentage points in our study—when performed with others and at least twice a week."

Professor Okura's study collected data on 4,358 older (averaging 76.9 ± 5.6 years) adults in a regional city about 100 km (~62 miles) north of central Tokyo. This took place in 2017 to obtain baseline data for how frequently these people exercised alone or with others. The study team also used a local government database to collect follow-up data on the people's cognitive condition over nearly 4 years.

The researchers analyzed and calculated the data to find the relation between cognitive decline, exercise, and exercise with others. They found that participants who exercised alone twice or more weekly decreased their risk of developing cognitive impairment by 15.1%. Yet those who exercised with others twice or more weekly showed a 29.2% decrease.

Studies reinforce these findings in various ways. Exercise can provide favorable physical and mental outcomes. It can also reduce chronic diseases such as hypertension and diabetes. Exercising in groups introduces a social element, and socializing has also been found to potentially reduce the development of cognitive disorders.

"A majority of the older adults in our study took part in exercise by themselves, and we can see the cognitive benefits when they do so at least twice a week," Professor Okura says. "Adding in the social element, however, may make regular exercise all the more preventive. Adopting this habit could be extremely valuable."

Further studies now need to look at factors such as exercise intensity and type. These findings may inform the development of specialized exercise programs that combine exercise and dementia for the prevention of dementia and other related conditions.

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This study was supported by a JSPS KAKENHI Grant-in-Aid for Scientific Research (B) (20H04063) to TO and by grants from Young Scientists (B) (26750348) to KT, JST COI-NEXT (JPMJPF2017) to TO, JST SPRING (JPMJSP2124) to KN, the Meiji Yasuda Life Foundation of Health and Welfare to TJ, and the Japan Sports Association to TO.
 

Dietary nitrate – found in beetroot juice - significantly increases muscle force during exercise

A new study has found that consuming dietary nitrate – the active molecule in beetroot juice – significantly increased muscle force while exercising. 

While it is known that dietary nitrate enhances exercise, both boosting endurance and enhancing high-intensity exercise, researchers still have much to learn about why this effect occurs, and how our bodies convert dietary nitrate that we ingest into the nitric oxide that can be used by our cells.

To help close this gap, researchers at the University of Exeter and the U.S. National Institutes of Health traced the distribution of ingested nitrate in the saliva, blood, muscle and urine of ten healthy volunteers, who were then asked to perform maximal leg exercise. The team wanted to discover where in the body the dietary nitrate was active, to give clues on the mechanisms at work.

An hour after the nitrate was taken, participants were asked to perform 60 contractions of the quadriceps – the thigh muscle active while straightening the knee – at maximum intensity over five minutes on an exercise machine. The team found a significant increase in the nitrate levels in muscle. During the exercises, researchers found this nitrate boost caused an increase in muscle force of seven per cent, compared to when the participants took a placebo.

Andy Jones, Professor of Applied Physiology at the University of Exeter, said: “Our research has already provided a large body of evidence on the performance-enhancing properties of dietary nitrate, commonly found in beetroot juice. Excitingly, this latest study provides the best evidence to date on the mechanisms behind why dietary nitrate improves human muscle performance.”

Previous studies had found an increase of nitrate in tissue and body fluid after ingesting labelled dietary nitrate. By using the tracer in the new study, researchers were able to accurately assess where nitrate is increased and active, and also shed new light on how the nitrate we consume is used to enhance exercise performance.

“This study provides the first direct evidence that muscle nitrate levels are important for exercise performance, presumably by acting as a source of nitric oxide,” said Dr Barbora Piknova, research collaborator and staff scientist in the National Institute of Diabetes and Digestive and Kidney Diseases at the National Institutes of Health. “These results have significant implications not only for the exercise field, but possibly for other medical areas such as those targeting neuromuscular and metabolic diseases related to nitric oxide deficiency.”

The research was conducted in collaboration with the University of Queensland, Australia, under the QUEX partnership with Exeter.

The paper is entitled ‘N-labelled dietary nitrate supplementation increases human skeletal muscle nitrate concentration and improves muscle torque production’, and is published in the journal Acta Physiologica.

Orienteering can train the brain, may help fight cognitive decline

 

IMAGE: JENNIFER HEISZ & EMMA WADDINGTON KINESIOLOGIST JENNIFER HEISZ (RIGHT) AND GRADUATE STUDENT EMMA WADDINGTON (LEFT) EXAMINED THE SPORT OF ORIENTEERING’S USEFULNESS IN FIGHTING COGNITIVE DECLINE. view more 

CREDIT: KAYLA DA SILVA/MCMASTER UNIVERSITY

The sport of orienteering, which draws on athleticism, navigational skills and memory, could be useful as an intervention or preventive measure to fight cognitive decline related to dementia, according to new research from McMaster University.

Researchers hypothesized that the physical and cognitive demands of orienteering, which integrates exercise with navigation, may stimulate parts of the brain that our ancient ancestors used for hunting and gathering. The brain evolved thousands of years ago to adapt to the harsh environment by creating new neural pathways. 

Those same brain functions are not as necessary for survival today due to modern conveniences such as GPS apps and readily available food. Researchers suggest it is a case of “use it or lose it.”

“Modern life may lack the specific cognitive and physical challenges the brain needs to thrive,” says Jennifer Heisz, Canada Research Chair in Brain Health and Aging at McMaster University, who supervised the research. “In the absence of active navigation, we risk losing that neural architecture.”

Heisz points to Alzheimer’s disease, in which losing the ability to find one’s way is among the earliest symptoms, affecting half of all afflicted individuals, even in the mildest stage of the disease.

In the study, published today in the journal PLoS ONE, researchers surveyed healthy adults, ranging in age from 18 to 87 with varying degrees of orienteering expertise (none, intermediate, advanced and elite).

People who participate in orienteering reported better spatial navigation and memory, suggesting that adding elements of wayfinding into regular workouts could be beneficial over the span of a lifetime.  

“When it comes to brain training, the physical and cognitive demands of orienteering have the potential to give you more bang for your buck compared to exercising only,” says lead author Emma Waddington, a grad student in the Department of Kinesiology who designed the study and is a coach and member of the national orienteering team. 

The goal of orienteering is to navigate by running as quickly as possible over unfamiliar territory, finding a series of checkpoints using only a map and compass.  The most skillful athletes must efficiently switch between several mental tasks, making quick decisions while moving across the terrain at a rapid pace.

The sport is unique because it requires active navigation while making quick transitions between parts of the brain that process spatial information in different ways. For example, reading a map depends on a third-person perspective relative to the environment. Orienteers must quickly translate that information relative to their own positions within the environment, in real-time, as they run the course.  

It is a skill which GPS systems have engineered out of modern life, say researchers. That may affect not only our ability to navigate but also affect our spatial processing and memory more generally because these cognitive functions rely on overlapping neural structures. 

Researchers suggest there are two simple ways to incorporate more orienteering into daily life: turn off the GPS and use a map to find your way when travelling and challenge yourself—spatially—by using a new route for your run, walk or bike ride.

“Orienteering is very much a sport for life. You can often see participants spanning the ages of 6 to 86 years old engaged in orienteering,” says Waddington. “My long-term involvement in this sport has allowed me to understand the process behind learning navigational skills and I have been inspired to research the uniqueness of orienteering and the scientific significance this sport may have on the aging population,” says Waddington.

 

 

Omega 3 fatty acids in seafood linked to lower risk of chronic kidney problems

Higher levels of omega 3 fatty acids found in seafood are associated with a moderately lower risk of chronic kidney disease and a slower decline in kidney function, finds a study published by The BMJ.

These associations were not found with higher levels of plant derived omega 3 fatty acids. 

Although the size of these associations was modest, the findings support current clinical guidelines that recommend adequate consumption of seafood and oily fish as part of healthy dietary patterns, say the researchers.

Chronic kidney disease (CKD) affects about 700 million people worldwide and can lead to kidney failure and death, so there is a need to identify factors that might prevent its onset and progression.

Animal studies suggest that omega 3 polyunsaturated fatty acids (n-3 PUFAs) may have beneficial effects on kidney function, but evidence from human studies is limited and relies mainly on dietary questionnaires, which can be prone to error.

To explore this further, an international team led by researchers at The George Institute for Global Health and the University of New South Wales, pooled the results of 19 studies from 12 countries up to May 2020 looking at links between levels of n-3 PUFA biomarkers and development of CKD in adults.

Biomarkers included eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), docosapentaenoic acid (DPA), and alpha linolenic acid (ALA). The main dietary sources of EPA, DHA and DPA come from seafood, while ALA is found mainly in plants (nuts, seeds, and leafy green vegetables). 

CKD was identified by an estimated glomerular filtration rate (eGFR) of less than 60 ml/min/1.73 m2. eGFR measures how well the kidneys are removing waste and excess fluid from the blood. The normal range is 90-120 ml/min/1.73 m2.

Overall, 25,570 participants were included in the main analysis. Their average age ranged from 49 to 77 years and their average baseline eGFR ranged from 76.1 to 99.8 mL/min/1.73 m2.

Sixteen studies recruited men and women, and 15 recruited mainly white participants. In total, 4,944 participants (19%) developed CKD during an average monitoring period of 11 years.

After accounting for other a range of factors including age, sex, race, body mass index, smoking, alcohol intake, physical activity, heart disease and diabetes, higher levels of total seafood n-3 PUFAs were associated with a modest (8%) lower risk of developing CKD.

When participants were split by n-3 PUFA levels, those with total seafood n-3 PUFA levels in the highest fifth had a 13% lower risk of CKD compared with those in the lowest fifth. 

Higher levels of total seafood n-3 PUFAs, especially DHA, were also associated with a slower annual decline in eGFR. For instance, the annual decline in eGFR was 0.07 mL/min/1.73 m2 lower for people with total seafood n-3 PUFA level in the highest fifth than those in the lowest fifth.

Plant derived ALA levels were not associated with CKD.

These are observational findings and the researchers acknowledge that differences in study design and methods may have affected their results. And they cannot rule out the possibility that some of the observed risk may be due to unmeasured factors.

Nevertheless, results were similar after further analysis, and appeared consistent across age groups (60 or less v more than 60 years), eGFR (60-89 v 90 or higher mL/min/1.73 m2), high blood pressure, diabetes, and coronary heart disease at baseline, suggesting that they withstand scrutiny.

“Although our findings do not prove a causal relation between seafood n-3 PUFAs and CKD risk, they are supportive and consistent with current clinical guidelines that recommend adequate intake of seafood as part of healthy dietary patterns, especially when seafood replaces the intake of less healthy foods,” they write.

“Further randomised controlled trials are warranted to assess the potential beneficial role of seafood n-3 PUFAs in preventing and managing CKD,” they add.

What makes brown rice healthy?

 

IMAGE: SEVERAL FAT-SOLUBLE COMPOUNDS PRESENT IN BROWN RICE HAVE ANTIOXIDANT CAPACITY BUT ARE PRESENT IN SMALL QUANTITIES. CYCLOARTENYL FERULATE, A RELATIVELY ABUNDANT MOLECULE, HAS BEEN REVEALED AS THE MAJOR COMPOUND RESPONSIBLE FOR SEVERAL HEALTH BENEFITS OF BROWN RICE. view more 

CREDIT: YOSHIMASA NAKAMURA

Asian diets feature rice as a staple grain, contributing towards nearly 90% of the world’s rice consumption. Brown rice, in particular, is known to have several health benefits. As a regular addition to the diet, it can help reduce body weight, lower cholesterol, and suppress inflammation. The ability of brown rice to neutralize reactive oxygen species and prevent cellular damage is vital to many of its health-promoting effects. Although previous studies have shown that the antioxidant compounds in brown rice can protect cells against oxidative stress, knowledge regarding which major compound contributes towards these beneficial properties has long remained a mystery.

 

In a recent study led by Professor Yoshimasa Nakamura from the Graduate School of Environmental and Life Science, Okayama University, researchers from Japan have identified cycloartenyl ferulate (CAF) as the main “cytoprotective” or cell-protecting compound in brown rice. CAF is a unique compound owing to its hybrid structure. As Professor Nakamura explains, “CAF is a hybrid compound of polyphenol and phytosterol and is expected to be a potent bioactive substance with various pharmacological properties, such as antioxidant effect and blood fat-lowering effect.”

 

The study published on January 3, 2023 in volume 24 issue 1 of International Journal of Molecular Sciences, was co-authored by Hongyan Wu, from Dalian Polytechnic University, and Toshiyuki Nakamura, from the Graduate School of Environmental and Life Science at Okayama University. In it, the researchers provide evidence of CAF’s antioxidant properties by demonstrating that it can protect cells from stress caused by hydrogen peroxide. Although hydrogen peroxide is a by-product of a cell’s metabolic processes, abnormal amounts of the compound can be toxic to cells and cause irreversible damage. Treatment of cells with CAF increased their resistance to toxic stress induced by hydrogen peroxide. Moreover, CAF provided greater protection from hydrogen peroxide-induced stress compared to alpha-tocopherol and gamma-tocopherol, two other prominent antioxidant compounds that were earlier speculated to be major contributors to the antioxidant capacity of brown rice.

 

According to the study’s estimates, the amount of CAF in the whole grain of brown rice is five-fold higher than that of other antioxidant compounds found in brown rice. Further, CAF increases the concentration of heme oxygenase-1 or HO-1, an enzyme that facilitates the production of antioxidants. “We demonstrated here that CAF significantly increased the mRNA level of HO-1, the small molecular weight antioxidant-producing enzyme, at concentrations similar to that required for cytoprotective effects in resistance to oxidative damage,” Professor Nakamura explains.

 

The researchers further explored this mechanism of action through experiments where blocking HO-1 activity using inhibitors reduced the antioxidant effect of CAF considerably. The high abundance and unique mechanism of action are evidence that CAF is the major contributing antioxidant in brown rice.

 

Through this study, the researchers have not only uncovered the secret to the health benefits of brown rice, but also locked down on the component that is majorly responsible for these benefits. This will allow the use of CAF in the development of better novel supplements and food products focused on consumer health. As an optimistic Professor Nakamura observes, “Our study can help in the development of new functional foods and supplements based on the functionality of CAFs, like CAF-based nutraceuticals.”

 

Although, with such naturally occurring health benefits, brown rice still very much looks to be on the menu!

Reducing total calories may be more effective for weight loss than intermittent fasting

Timing from first meal to last meal was not associated with weight loss in a six-year study published in the Journal of the American Heart Association

Research Highlights:

• Eating less overall and fewer large meals may be a more effective weight management strategy than restricting meals to a narrow time window, such as intermittent fasting, according to a study that analyzed the electronic health records of about 550 adults who were followed for six years.
• The time interval from first to last meal was not associated with weight change during the six-year study.

The frequency and size of meals was a stronger determinant of weight loss or gain than the time between first and last meal, according to new research published today in the Journal of the American Heart Association, an open access, peer-reviewed journal of the American Heart Association.

According to the senior study author Wendy L. Bennett, M.D., M.P.H., an associate professor of medicine at Johns Hopkins University School of Medicine in Baltimore, although ‘time-restricted eating patterns’ - known as intermittent fasting - are popular, rigorously designed studies have not yet determined whether limiting the total eating window during the day helps to control weight.

This study evaluated the association between time from the first meal to last meal with weight change. Nearly 550 adults (18 years old or older) from three health systems in Maryland and Pennsylvania with electronic health records were enrolled in the study. Participants had at least one weight and height measurement registered in the two years prior to the study’s enrollment period (Feb.-July 2019).

Overall, most participants (80%) reported they were white adults; 12% self-reported as Black adults; and about 3% self-identified as Asian adults. Most participants reported having a college education or higher; the average age was 51 years; and the average body mass index was 30.8, which is considered obese. The average follow-up time for weight recorded in the electronic health record was 6.3 years.

Participants with a higher body mass index at enrollment were more likely to be Black adults, older, have Type 2 diabetes or high blood pressure, have a lower education level, exercise less, eat fewer fruits and vegetables, have a longer duration from last mealtime to sleep and a shorter duration from first to last meal, compared to the adults who had a lower body mass index.

The research team created a mobile application, Daily24, for participants to catalog sleeping, eating and wake up time for each 24-hour window in real time. Emails, text messages and in-app notifications encouraged participants to use the app as much as possible during the first month and again during “power weeks” — one week per month for the six-month intervention portion of the study.

Based on the timing of sleeping and eating each day recorded in the mobile app, researchers were able to measure:

• the time from the first meal to the last meal each day;
• the time lapse from waking to first meal; and
• the interval from the last meal to sleep.

They calculated an average for all data from completed days for each participant.

The data analysis found:

• Meal timing was not associated with weight change during the six-year follow-up period. This includes the interval from first to last meal, from waking up to eating a first meal, from eating the last meal to going to sleep and total sleep duration.
• Total daily number of large meals (estimated at more than 1,000 calories) and medium meals (estimated at 500-1,000 calories) were each associated with increased weight over the six-year follow up, while fewer small meals (estimated at less than 500 calories) was associated with decreasing weight.
• The average time from first to last meal was 11.5 hours; average time from wake up to first meal measured 1.6 hours; average time from last meal to sleep was 4 hours; and average sleep duration was calculated at 7.5 hours.
• The study did not detect an association meal timing and weight change in a population with a wide range of body weight.

As reported by Bennett, even though prior studies have suggested intermittent fasting may improve the body’s rhythms and regulate metabolism, this study in a large group with a wide range of body weights did not detect this link. Large-scale, rigorous clinical trials of intermittent fasting on long-term weight change are extremely difficult to conduct; however, even short-term intervention studies may be valuable to help guide future recommendations.

Although the study found that meal frequency and total calorie intake were stronger risk factors for weight change than meal timing, the findings could not prove direct cause and effect, according to lead study author Di Zhao, Ph.D., an associate scientist in the division of cardiovascular and clinical epidemiology at Johns Hopkins Bloomberg School of Public Health.

Researchers note there are limitations to the study since they did not evaluate the complex interactions of timing and frequency of eating. Additionally, since the study is observational in nature, the authors were unable to conclude cause and effect. Future studies should work toward including a more diverse population, since the majority of the study’s participants were well-educated white women in the mid-Atlantic region of the U.S., the authors noted author.

Researchers also were not able to determine the intentionality of weight loss among study participants prior to their enrollment and could not rule out the additional variable of any preexisting health conditions.

According to the American Heart Association’s 2022 statistics, 40% of adults in the U.S. are obese; and the Association’s current diet and lifestyle recommendations to reduce cardiovascular disease risk include limiting overall calorie intake, eating healthy foods and increasing physical activity.

Additional Resources:

• Multimedia is available on the right column of release link https://newsroom.heart.org/news/reducing-total-calories-may-be-more-effective-for-weight-loss-than-intermittent-fasting?preview=28d0ab1275acbbf55f30bb41c534f37a
• After Jan. 18, 2023, view the manuscript online.
• AHA health information: 5 Steps to Lose Weight and Keep It Off
• AHA health information: Keeping a Healthy Body Weight
• Follow AHA/ASA news on Twitter @HeartNews
• Follow news from the Journal of the American Heart Association @JAHA_AHA
•