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There has been a lot of discussion recently about whether older adults form new neurons in the brain. Neurons are specialized cells transmitting nerve impulses in the brain - they are nerve cells. In other words, if elderly people form new neurons in the brain, then this is excellent news for brain function. This means we can look for ways to enhance neurogenesis (formation of new neurons) and slow or prevent cognitive decline, whether in diseases such as Alzheimer's or normal age-related cognitive declines. Because yes, it is normal to have age-related declines, but some people have more declines while others far, far less.

Researchers at the University of Illinois at Chicago studied the hippocampus of 18 elderly brains (mean age 90.6 years!) after death (post-mortem). They found both new neural stem cells (neural progenitor cells) and developing neurons in each person's brain, but the numbers varied a lot between the brains. For example, brains with evidence of Alzheimer's disease and cognitive impairments had significantly fewer developing neurons than those without cognitive declines.

These results go hand in hand with studies showing a number of known age related brain changes, such as the volume of the brain shrinking a little as we age (this is considered normal). Studies find that there are ways to slow down this shrinkage such as good nutrition (including nuts, fruits and vegetables, coffee or tea containing caffeine, eating seafood), physical activity, exercise, having mentally stimulating activities. Also, avoiding medicines with anticholinergics, and avoiding air pollution and an unhealthy Western style diet (highly processed foods, low fiber, lots of meat).

From Medical Xpress: New neurons form in the brain into the tenth decade of life, even in people with Alzheimer's  ...continue reading "New Neurons Form In the Brains Of Older Adults"

Great news for those who don't exercise at government recommended guideline levels of 150 minutes of moderate to vigorous activity per week. Which may be most of us, perhaps? Hmmm? A recent study found that even light intensity exercise is beneficial to the brain.

The study of 2354 persons (average age 53 years) in Framingham, Massachusetts, found that each additional hour spent in light-intensity physical activity was associated with a larger brain volume - equivalent to approximately 1.1 years less brain aging. Thus, the more activity, the more beneficial. In general, total cerebral brain volume declines at a rate of 0.2% per year after age 60 years - so slowing this process down is desirable.

Both physical activity levels and steps per day was looked at, and both were beneficial to brain volume. The study found that walking 10 ,000 or more steps per day was associated with higher brain volume when compared with persons who walked fewer than 5000 steps per day. But even 7500 steps was better for the brain than 5000 steps. How did they measure brain volume? With brain MRI imaging. 

This study found that light exercise is beneficial to the brain, specifically the brain volume - but note that these benefits are from levels below official recommended guidelines. The US Department of Health and Human Services (HHS) 2018 Physical Activity Guidelines for Americans state that 150 or more minutes of moderate to vigorous physical activity (MVPA) per week is recommended for substantial health benefits (but they also said that "some physical activity is better than none"). In other words, get off your butt and move - any activity and exercise is better than none!

From Science News: Light, physical activity reduces brain aging

Incremental physical activity, even at light intensity, is associated with larger brain volume and healthy brain aging ...continue reading "Light Physical Activity Is Beneficial to the Brain"

Once again a study found benefits from exercise - specifically that regular exercise is better for the brain and for thinking skills (for "executive function"). Executive function is a person's ability to regulate his or her own behavior, pay attention, manage new information and unexpected challenges, to plan, organize, and achieve goals. Executive functioning can decline in older adults - "age-related declines". So it's definitely beneficial to prevent or slow down a decline in thinking skills.

In this study 132 individuals (aged 20 to 67 years) living in New York City were either randomly assigned to a stretching group or an aerobic exercise group for 6 months. They were given a number of tests (at the start, at 3 mos, and at 6 mos.) to measure executive function, memory, IQ, etc. After 6 months the aerobic exercise group had a number of benefits (compared to the stretching group): they reduced their BMI (body mass index), they increased the cortical thickness in a part of their brain (this is good), and they had improved executive function thinking. The researchers found that the aerobic exercise showed more benefit to older adults than the younger adults.

How much did the aerobic group exercise? The individuals had 4 sessions a week of aerobic exercise (stationary cycling, treadmill, elliptical machine) which consisted of 10 to 15 minutes of warm-up/cool down, and 30 to 40 minutes of exercise. Note that at the start of the study all persons were healthy, sedentary non-exercisers - with "below median aerobic capacity". Meaning that there is hope for all of us to benefit from regular exercise whether a young adult or over 60.

For those persons that dread going to a gym or spend money for exercise equipment  - you don't need it! Just get out and walk briskly, or ride a bicycle, climb stairs regularly - in other words, move! The goal is to get your heart pumping. From Science Daily -

Exercise may improve thinking skills in people as young as 20

Regular aerobic exercise such as walking, cycling or climbing stairs may improve thinking skills not only in older people but in young people as well, according to a study published in the January 30, 2019, online issue of Neurology®, the medical journal of the American Academy of Neurology. ...continue reading "Aerobic Exercise, Thinking Skills, and the Brain"

Another study finding more benefits of exercise was recently published in the journal Neurology. The study by researchers at Duke University found that in older adults who were already experiencing  cognitive (thinking) problems, but did not have dementia - that after just 6 months of exercise they showed improvements in thinking. What were their original thinking problems? The individuals had difficulty concentrating, making decisions, or remembering, but it was not severe enough to be diagnosed as dementia. However, these persons were considered at risk for progressing to dementia.

The 160 individuals in the study were 55 years or older (mean age 65), mainly women, evenly divided between whites and minorities, were sedentary (didn't exercise), and had heart (cardiovascular) disease or were at risk for heart disease. They were randomly assigned to one of 4 groups: 1) aerobic exercise (with no dietary changes), 2) DASH diet (with no exercise), 3) DASH diet plus exercise, and 4) the control group, who had no dietary or exercise changes - they just received some educational phone calls. The study lasted 6 months, and there were no drop outs.

In the study, the aerobic exercises were done 3 times per week: 10 minutes of warm up exercises followed by 35 minutes of continuous walking or stationary cycling. The Dietary Approaches to Stop Hypertension or DASH diet is a heart healthy diet that emphasizes eating fruits, vegetables, whole grains, as well as fish, poultry, beans, and nuts. It stresses lowering the intake of salt (sodium), sweets, sugar sweetened beverages, and fatty foods (both trans fats and saturated fats). [Note that in many ways it's similar to the Mediterranean diet with its emphasis on fruits, vegetables, whole grains, legumes, seeds, nuts, and lowering intake of meat. Studies find cognitive benefits from the Mediterranean diet.]

The six months of exercising improved thinking skills called executive function - in both the exercise alone or exercise + DASH diet group. The largest improvements were in the exercise + DASH diet group (as compared to the control group, which actually showed decline in functioning). Executive function is a person's ability to regulate their own behavior, pay attention, organize and achieve goals, and was measured in this study with a group of cognitive tests (a "standard battery of neurocognitive tests"). These executive function improvements did not occur in the DASH diet alone group or the control group. The study found no improvement in memory or language fluency in any of the groups. The exercise alone, DASH diet alone, and the combined exercise and DASH group had other health benefits by the end of the study, for example they lowered their risk factors for heart disease. Other improvements: the exercise groups had improvements in insulin levels, and the DASH groups decreased their intake of blood pressure medicines.

To illustrate how amazing these results are: at the start of the study (baseline) all participants scored as if they were in their early 90s on cognitive tests - as if they were on average about 28 years older than their actual chronological age! Then at the end of 6 months, the persons in the exercise + DASH diet showed an improvement of almost 9 years on the tests. In contrast, the control group showed an approximately 6 month worsening performance. When researchers looked at physical markers of the exercisers, they found that physical improvements and improvements in heart disease risk factors (e.g. losing weight, lowering blood pressure) were correlated with executive functioning improvements.

Other studies have found related findings, such as higher physical activity and a Mediterranean diet is associated with lower levels of dementia. The researchers point out that there is growing evidence that combining several lifestyle factors (e.g., exercise, not smoking, a healthy diet, lowering salt intake) and not just exercise alone, has the best results for better cognitive functioning among older adults. Bottom line: eat a diet rich in fruits, vegetables, whole grains, seeds, nuts and get exercise. Walking briskly, gardening, housework, walking up stairs - it all counts.  ...continue reading "Can Exercise and Dietary Changes Help Older Adults With Thinking Problems?"

The results of a recent study suggested that walking 4 hours or more a week or 2 to 3 hours of moderate physical activity may have a (slight) protective effect of reducing stroke severity in persons who get a stroke. The study, which was conducted in Sweden, found that persons who were physically more active before their stroke and were younger in age were more likely to have a mild stroke (rather than a moderate or severe stroke). This finding was an association (didn't prove it).

But ...the majority of persons participating in the study - whether they exercised or not before the stroke - had mild strokes, and a minority in all of the groups had moderate or severe strokes. 73% of physically inactive people, 85% of those with light physical activity, and 89% of  those who had engaged in moderate physical activity before their strokes had mild strokesResearchers found that light (walking or a similar activity for at least 4 hours per week) and moderate physical activity (2 to 3 hours per week) were equally beneficial. From Medical Xpress:

People who walk just 35 minutes a day may have less severe strokes

People who participate in light to moderate physical activity, such as walking at least four hours a week or swimming two to three hours a week, may have less severe strokes than people who are physically inactive, according to a study published in the September 19, 2018, online issue of Neurology, the medical journal of the American Academy of Neurology. 

...continue reading "Could Physical Activity Reduce Stroke Severity?"

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Nice study that explains why sitting for long periods is so unhealthy - it reduces blood flow to the brain (cerebral blood flow) . The results from a study conducted in the United Kingdom (UK) found that prolonged, uninterrupted sitting (4 hours in the study) in healthy office workers reduced cerebral blood flow. However this was offset when frequent, short-duration walking breaks were taken - about 2 minutes of walking every 30 minutes. However, taking a 8 minute walking break every 2 hours did not have the same positive effect - even though that was the same amount of walking over the 4 hour period.

Maintaining good blood flow to the brain is a great reason to stretch your legs and walk a few minutes whenever possible, preferably at least every 30 minutes - whether at work or at home. From Medical Xpress:

Sitting for long hours found to reduce blood flow to the brain

A team of researchers with Liverpool John Moores University in the U.K. has found evidence of reduced blood flow to the brain in people who sit for long periods of time. In their paper published in the Journal of Applied Physiology, the group outlines the experiments they carried out with volunteers and what they found.  ...continue reading "Sitting For Long Periods and Reduced Blood Flow To the Brain"

Walk, walk, walk for health - and the faster, the better. The message from a  large study (in Britain and Scotland) is that walking is associated with healthier, longer lives - but if you walk at a fast pace (brisk walking), the effects are even better. Walking at an average or brisk pace reduced death (from any cause) by 20% to 24% - as compared to those walking slowly. Heart disease deaths were reduced by  21% to 24% at an average or brisk pace - when compared to those walking at a slow pace.

Bottom line: average walking pace is good, but getting your heart rate up (and getting a little sweaty) while walking briskly is better. By the wayr, the researchers did not find any effect of walking speed on cancer deaths.  ...continue reading "Walking At a Brisk Pace Is Best For Health"

The last post dealt with the link between highly processed food and increased risk of cancer. Now an interesting article written by Dr. Lisa Mosconi (Associate Director of the Alzheimer’s Prevention Clinic at Weill Cornell Medical College/New York -Presbyterian Hospital) refers to that study when discussing research about lifestyles (and especially diet) and later Alzheimer's disease.

It'll be interesting to see how this research plays out - is her approach stressing diet (and avoiding ultra-processed food and trans fats) and lifestyle correct or not? Much of what she says definitely makes sense and is supported by research, such as the negative health effects of chronic inflammation, and how eating actual, real foods has beneficial health effects. On the other hand, vitamin, mineral, and fish oil supplements generally don't show those health benefits (as she discusses here).

Currently there are a number of theories about causes of Alzheimer's disease (including the role of microbes), as well as a number of drug treatments that so far have gone nowhere. If Dr. Mosconi's research interests you, then read the interview she did in 2017. [In the interview she talks about the importance of exercise, intellectual stimulation, social networks, and the benefits of eating real foods rather than supplements. She recommends: drink water, eat fish, eat vegetables and fruit, eat glucose rich foods, and don't eat highly processed and fast foods.]  From Quartz:

The road to Alzheimer’s disease is lined with processed foods

Dementia haunts the United States. There’s no one without a personal story about how dementia has touched someone they care for. But beyond personal stories, the broader narrative is staggering: By 2050, we are on track to have almost 15 million Alzheimer’s patients in the US alone. ... It’s an epidemic that’s already underway—but we don’t recognize it as such. The popular conception of Alzheimer’s is as an inevitable outcome of aging, bad genes, or both.  ...continue reading "Ultra-Processed Foods and Alzheimer’s?"

A new observational study from Taiwan found that having one of eight chronic diseases, such as heart disease or diabetes, or their markers (e.g. high cholesterol levels as a marker for heart disease), also significantly raises the person's odds of developing cancer or dying from cancer. The study estimated that these diseases or markers accounted for about 20% of all new cancers and 39% of all cancer deaths. That's about the risk of 5 lifestyle factors combined (smoking, alcohol consumption, obesity, unhealthy diet, and lack of exercise) contributing to cancer development and death.

The eight chronic diseases and markers were: cardiovascular disease (markers for which include blood pressure, total cholesterol, and heart rate), diabetes, chronic kidney disease (markers for which include proteinuria and glomerular filtration rate), pulmonary disease, and gouty arthritis (for which uric acid is a marker). The higher the chronic disease and marker score, the higher the risk of developing cancer and cancer death (a dose-response). Chronic diseases and markers were associated with a shortened lifespan -  about 13.3 years in men and 15.9 years in women.

But the good news is that regular physical exercise lowers the risk of developing cancer by about 48% and the risk of cancer death by 27%. That's huge!  So physical exercise and activity could be viewed as "cancer prevention" strategies. The researchers pointed out that additional cancer prevention strategies are avoiding smoking (very important), avoiding excessive alcohol consumption, maintaining healthy weight, and a healthy diet. From Science Daily:

Substantial impact of chronic diseases on cancer risk

Several common chronic diseases together account for more than a fifth of new cancer cases and more than a third of cancer deaths, finds a study published by The BMJ today. The findings show that the cancer risks from common chronic diseases, such as heart disease and diabetes, are as important as those from five major lifestyle factors combined.

A team of researchers based in the US and Taiwan therefore set out to investigate the combined effect of eight common chronic diseases or disease markers (for example, high blood pressure as a marker of heart disease) on cancer risk compared with lifestyle factorsThey also explored whether physical activity could reduce the cancer risk associated with chronic diseases and disease markers. The study involved 405,878 men and women in Taiwan with no history of cancer .... underwent a series of medical tests between 1996 and 2007. .... Participants were followed for an average of 8.7 years.

The researchers found that cardiovascular disease markers, diabetes, chronic kidney disease markers, pulmonary disease, and gouty arthritis marker were individually associated with risk of developing cancer or cancer death. Higher chronic disease risk scores based on these diseases or markers were linked with an increased risk of developing cancer and cancer death, with the highest level associated with a more than twofold increase in risk of developing cancer and a fourfold increase in risk of cancer death.

High chronic disease risk scores were also associated with substantial reduction in life span. The highest scores were associated with 13.3 years of life lost in men and 15.9 years of life lost in women. Together, these chronic diseases and markers accounted for more than one fifth of all new cancers and more than one third of all cancer deaths in this study population, which was similar to the contribution of five major lifestyle risk factors combined -- smoking, insufficient physical activity, insufficient fruit and vegetable intake, alcohol consumption, and obesity.

The researchers also found that physical activity was associated with a nearly 40% reduction in the excess risks of cancer and cancer death associated with chronic diseases and markers. [Original study.]

A new study's results actually made me ask - this was a surprise? Of course more fit people have lower levels of chronic inflammation and smaller waist size, no matter their Body Mass Index (BMI) - which includes their weight. And the reverse is also true (lower fitness levels are associated with greater waist size and higher levels of chronic inflammation, no matter the BMI). Which means that being fit, no matter the weight, has health benefits. From Medical Xpress:

Low fitness is associated with larger waist size and higher degree of inflammation

Low fitness is associated with a larger waist size and a higher degree of inflammation, according to a study published January 17, 2018 in the open-access journal PLOS ONE by Anne-Sophie Wedell-Neergaard from the University of Copenhagen, Denmark, and colleagues.

Waist circumference can indicate the amount of excess fat found around the abdomen and previous studies have shown excess abdominal fat may increase the risk of chronic system inflammation and metabolic diseases. The authors of the present study sought to investigate the association between fitness and waist circumference as well as the association between fitness and low-grade inflammation, and whether there was a correlation with Body Mass Index (BMI).

The researchers analyzed the previously collected data of 10,976 individuals from The Danish National Health Examination Survey 2007-2008. These individuals took a maximal oxygen uptake (VO2max) test to assess their physical fitness. Their waist circumference, weight and height were measured, and blood samples were taken to measure their level of C-reactive protein, a nonspecific biomarker of low-grade inflammation.

The researchers found that higher levels of fitness were associated with a smaller waist circumference and a lower degree of inflammation independently of BMI. The researchers acknowledge that there are possible limitations that may affect the findings of the study, but overall the results suggest that increased fitness has the potential to reduce abdominal fat mass and inflammation which may improve metabolic health irrespective of BMI