Reaction Time Variation May be a Marker that Predicts Mortality in Old Age

A common indicator of neurobiological disturbance among the elderly may also be associated with mortality, according to a study published August 9, 2017 in the open access journal PLOS ONE by Nicole A. Kochan at the Centre for Healthy Brain Ageing (CHeBA), UNSW Sydney.

Intraindividual reaction time variability (IIVRT), defined as an individual’s variation in reaction times when completing a single cognitive task across several trials, has been associated with mild cognitive decline, dementia and Parkinson’s disease. The authors of this study investigated whether IIVRT is also associated with mortality in old age by following a cohort of 861 adults aged 70 years to 90 years over an eight-year period.

Kochan and colleagues tested the participants’ baseline reaction time by having them complete two brief computerized cognitive tasks comprising 76 trials to measure the average reaction time and the extent of variation over the trials. Every two years, research psychologists followed up on the participants and conducted a comprehensive medical assessment including a battery of neuropsychological tests to assess the participants’ cognitive function. Cases were also reviewed by a panel of experts to determine a dementia diagnosis in each two year follow-up, and mortality data was collected from the state registry.

Study results indicate that greater IIVRT predicted all-cause mortality, but the average RT did not predict time to death. Researchers found that other risks factors associated with mortality such as dementia, cardiovascular risk and age could not explain the association between IIVRT and mortality prediction. The authors suggested that IIVRT could therefore be an independent predictor of shorter time death.

“The study was the first to comprehensively account for effects of overall cognitive level and dementia on the relationship between intraindividual variability of reaction time and mortality,” says Kochan. “Our findings suggest that greater intraindividual reaction time variability is a behavioural marker that uniquely predicts shorter time to death.”

Source: Science Daily


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Yoga May Boost Aging Brains

Amy Norton wrote . . . . . .

Older women who practice yoga may have greater “thickness” in areas of the brain involved in memory and attention, a small study suggests.

Researchers found that even compared with other healthy, active women their age, yoga practitioners typically had greater cortical thickness in the brain’s left prefrontal cortex.

That could be good news because, as the researchers pointed out, cognitive impairment from aging is usually associated with less volume in cortical areas of the brain associated with attention tasks, and decreases in memory.

But experts said it’s not clear what conclusions can be drawn from the study’s findings.

The findings are based on one-time brain scans of fewer than 50 women — and they do not prove that yoga, itself, altered anyone’s brain structure, according to senior researcher Elisa Kozasa.

The brain differences might have existed before the women ever tried yoga, said Kozasa, a researcher at Hospital Israelita Albert Einstein in Sao Paulo, Brazil.

But the study does add to a bigger body of evidence on yoga and brain function, said Dr. Helen Lavretsky, a researcher who was not involved in the work.

“This contributes to the evidence that yoga practice has neuroplastic effects on the brain that may translate into other health benefits — like better mood and cognition,” said Lavretsky, a professor-in-residence of psychiatry at the UCLA Geffen School of Medicine.

“Neuroplasticity” refers to the brain’s ability to reorganize itself and form new connections among cells over the course of a lifetime.

In her own research, Lavretsky has found some evidence that yoga benefits older adults’ brain function.

In a recent pilot study, her team tested the effects of weekly yoga classes among 25 older adults who were showing early signs of memory problems. The participants were randomly assigned to 12 weeks of yoga — which included some movement, breathing practices and meditation — or 12 weeks of “brain games.”

In the end, both groups were doing a little better on standard memory tests, compared with the study’s outset. But the yoga group showed a bigger change.

According to Lavretsky, it’s possible that yoga benefits the brain over time by easing day-to-day stress. Or, she said, yoga practices might have a more direct effect on “brain fitness.”

Kozasa pointed out that yoga involves a “cognitive component,” where practitioners hone their ability to concentrate while consciously holding poses, performing breathing exercises and meditating.

Her team was interested in whether long-time practitioners actually show a difference in their brain structure.

So they performed brain scans of 42 women age 60 and older. Half of the women regularly practiced yoga — for the past 15 years, on average. The rest were healthy and physically active, but did not practice yoga.

Women in both groups also had similarly high education levels.

“Even with those similarities,” Kozasa said, “the yoga group presented a greater cortical thickness in brain regions involved in executive functions such as attention.”

However, there could be other explanations for the findings, Lavretsky said — such as differences in the two groups’ other lifestyle choices, sleep habits, or perceived stress levels.

Kozasa agreed. What’s needed, she said, is a long-term study that charts brain changes in yoga practitioners and non-practitioners over time.

And while some research suggests that yoga boosts memory and attention, it’s not clear whether the practice can curb older adults’ risk of dementia.

“It is too soon to state that yoga can protect your brain against dementia,” Kozasa stressed.

Still, she said, there’s no reason for older adults to delay trying yoga if they are interested.

“If practiced with an experienced instructor, older adults may get benefits from yoga for their mental and physical health,” Kozasa said.

The findings were published online recently in the journal Frontiers in Aging Neuroscience.

Source: HealthDay


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Protein at All 3 Meals May Help Preserve Seniors’ Strength

Alan Mozes wrote . . . . . .

Eating protein at all three daily meals, instead of just at dinner, might help seniors preserve physical strength as they age, new research suggests.

The Canadian study found that protein-rich meals evenly spread throughout the day staved off muscle decline, but did not increase mobility, in older people.

Study co-author Stephanie Chevalier said, for seniors, “The important point is to create three meal occasions with sufficient protein to stimulate muscle building and greater strength, instead of just one.”

Chevalier is an assistant professor of medicine at McGill University in Montreal.

The functional decline associated with aging often leads to falls, mental impairment and loss of independence. Chevalier’s team wondered if more evenly distributed protein consumption might be tied to better physical performance and a reduced rate of decline.

To find out, they tracked more than 1,700 relatively healthy Quebec men and women, aged 67 to 84, who were all enrolled in a three-year study.

The participants provided dietary information and underwent yearly hand, arm, and leg strength testing. They were also tested for mobility.

Over the three years, the researchers found that both men and women saw their overall physical performance worsen, with muscle strength fading more significantly than mobility.

But those who consumed protein more evenly throughout the day appeared to retain greater muscle strength — though not greater mobility — than those who consumed most of their protein late in the day.

However, Chevalier stressed the researchers only observed an association between protein distribution and muscle strength, not a direct cause-and-effect relationship.

“In other words, we cannot conclude that older people had greater strength because they were ingesting protein evenly distributed at every meal,” she said.

Establishing direct proof would require more research, she said.

Still, the study finding held up regardless of the total amount of protein consumed, she noted.

Prior research has indicated that adults of all ages should consume a minimum of 1.2 grams of protein per kilogram of body weight. (To convert pounds to kilograms, divide your body weight by 2.2.)

For a 155-pound man, that would add up to about three ounces of protein a day, Chevalier said. Spread across breakfast, lunch and dinner, that would mean about one ounce of protein at each meal. A 130-pound woman would require a little less than one ounce per meal.

The U.S. Department of Agriculture’s (USDA) Dietary Guidelines call for those over age 50 to consume 5 to 7 ounces of protein foods daily.

In general, one ounce of meat, poultry or fish or one egg or one tablespoon of peanut butter, one-quarter cup of cooked beans or one-half ounce of nuts or seeds qualify as an ounce of protein, according to the USDA.

An outside nutrition expert offered one explanation why the new findings might work.

“Muscle protein is constantly being broken down and built back up. We need protein in our diet daily to make this happen,” explained Lona Sandon, a dietetic educator.

That’s true at any age, but in late life muscle protein tends to break down faster than it builds up, added Sandon, an assistant professor of clinical nutrition at University of Texas Southwestern Medical Center at Dallas.

Also, research has shown older adults require a higher amount of protein, she said.

“Eating protein throughout the day seems to be a means to stay in a positive protein balance longer than just eating most of your protein for the day in the evening meal,” said Sandon.

Sandon said distributing protein intake evenly throughout the day is likely beneficial to everyone, young and old.

Much of the research in this area stems from sports nutrition studies, she added. “This research has also shown a benefit to spreading protein throughout meals over the day for increased muscle mass and strength benefits in active individuals and adults,” she added.

However, she cautioned that eating protein alone is not an anti-aging silver bullet.

“You can’t just eat a steak and suddenly have bulging biceps,” she said, noting the need for some level of physical activity or resistance training as well.

The study was published in the July issue of the American Journal of Clinical Nutrition.

Source: HealthDay


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Lutein May Yield Significant Cognitive Benefits

Researchers have found that lutein, a nutrient and organic pigment found in kale, spinach, avocados, and eggs, may be effective in rejuvenating cognitive functions.

The health benefits of green foods, such as kale, spinach, and other leafy vegetables, have long been discussed by nutritionists.

The importance of lutein – a nutrient and organic pigment, or carotenoid, found in a range of foods including kale, carrots, and even eggs – has often been singled out by specialists in recent studies. Medical News Today, for instance, have lately reported on lutein’s role in reducing inflammation in heart disease.

New research from the University of Illinois at Urbana-Champaign, in collaboration with the University of Georgia in Athens, has unveiled yet another health benefit of lutein: the ability to counteract cognitive aging.

Lead researcher Dr. Naiman A. Khan, of the Department of Nutritional Sciences at the University of Illinois, and his colleagues published their findings in the journal Frontiers in Aging Neuroscience.

Cognitive aging sets in early

The researchers started from the premise that cognitive aging becomes apparent earlier in life than one might expect.

Previous studies had only monitored cognitive aging in elderly adults, but Dr. Khan and his colleagues wanted to take a different approach.

“As people get older, they experience typical decline. However, research has shown that this process can start earlier than expected. You can even start to see some differences in the 30s,” says first study author Anne Walk, a postdoctoral researcher also at the University of Illinois.

With this in mind, the researchers recruited 60 adult participants aged between 25 and 45, setting out to investigate whether or not lutein intake can have an impact on cognition.

The researchers explain that lutein is a naturally occurring substance that cannot be synthesized in the human body. This is why it must be absorbed from foods that synthesize it, such as kale and other green leafy vegetables, or else through food supplements.

Once assimilated by the human body, lutein can be detected in brain tissue as well as in the eyes’ retinas, which makes the appraisal of lutein levels more convenient, as non-invasive measurements can be taken.

“If lutein can protect against decline, we should encourage people to consume lutein-rich foods at a point in their lives when it has maximum benefit,” says Walk.

More lutein improves cognitive performance

On this occasion, the researchers gauged lutein levels in the participants’ eyes by asking them to respond to flickering light stimuli.

The neural activity in the participants’ brains was assessed by electrodes attached to the scalp, as each participant was tasked with an attention-related exercise designed to test their selective attention, attentional inhibition (the ability to ignore irrelevant stimuli), or response inhibition (the ability to suppress inappropriate impulses).

Dr. Khan and colleagues found that the participants who exhibited higher levels of lutein were cognitively more similar to younger individuals than they were to individuals of the same age with lower lutein levels.

“The neuro-electrical signature of older participants with higher levels of lutein looked much more like their younger counterparts than their peers with less lutein. Lutein appears to have some protective role, since the data suggest that those with more lutein were able to engage more cognitive resources to complete the task,” explains Walk.

Following this study, the researchers seek to gain a better understanding of how a larger lutein intake might impact the level of the carotenoid accumulated in the retina, and to what extent lutein levels actually influence cognitive capacity.

“In this study we focused on attention, but we also would like to understand the effects of lutein on learning and memory,” concludes Dr. Khan.

Source: Medical News Today


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Study: Positive Attitude Toward Aging = Better Mood

A study of older adults finds an individual’s awareness of aging is not as static as previously thought, and that day-to-day experiences and one’s attitude toward aging can affect an individual’s awareness of age-related change (AARC) – and how that awareness affects one’s mood.

“People tend to have an overall attitude toward aging, good or bad, but we wanted to know whether their awareness of their own aging – or AARC – fluctuated over time in response to their everyday experiences,” says Shevaun Neupert, an associate professor of psychology at North Carolina State University and lead author of a paper on the study.

For the study, researchers enrolled 116 participants between the ages of 60 and 90. Each participant took a survey to establish baseline attitudes toward aging. For the following eight days, participants kept a log of daily stressors (such as having an argument), completed a daily evaluation of age-related experiences (such as “I am becoming wiser” or “I am more slow in my thinking”), and reported on their affect, or mood.

“We found that people’s AARC, as reflected in their daily evaluations, varied significantly from day to day,” says Jennifer Bellingtier, a recent Ph.D. graduate from NC State and co-author of the paper. “We also found that people whose baseline attitudes toward aging were positive also tended to report more positive affect, or better moods.”

“People with positive attitudes toward aging were also less likely to report ‘losses,’ or negative experiences, in their daily aging evaluations,” Neupert says.

“However, when people with positive attitudes did report losses, it had a much more significant impact on their affect that day,” Neupert says. “In other words, negative aging experiences had a bigger adverse impact on mood for people who normally had a positive attitude about aging.”

The study expands on previous work that found having a positive attitude about aging makes older adults more resilient when faced with stressful situations.

The paper, “Aging Attitudes and Daily Awareness of Age-Related Change Interact to Predict Negative Affect,” is published in the journal The Gerontologist.

Source: PsychCentral


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