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Category: brain

Published on Leave a comment on Can Cholesterol Levels Go Too Low?

Moderation seems best for so many things in life. And apparently this may also be true for a person's cholesterol levels. In a large study researchers found that having low levels of LDL cholesterol (below 70 mg/dL) significantly increased the risk of hemorrhagic stroke (intracerebral hemorrhage).Typically, lowering LDL (low-density lipoprotein) cholesterol is recommended as a way to reduce the risk of a heart attack or ischemic stroke, but several studies now confirm this very low LDL cholesterol - hemorrhagic stroke association.

The study was led by Pennsylvania State University researcher Xiang Gao, but conducted over a 9 year period in an industrial area in northern China. The 96,043 participants had their LDL cholesterol levels measured 4 times over that period. The researchers didn't find any increased risk of hemorrhagic stroke when LDL levels were above 70 mg/dL.

From Medical Xpress: Cholesterol that is too low may boost risk for hemorrhagic stroke

Current guidelines recommend lowering cholesterol for heart disease risk reduction. New findings indicate that if cholesterol dips too low, it may boost the risk of hemorrhagic stroke, according to researchers.  ...continue reading "Can Cholesterol Levels Go Too Low?"

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Published on 1 Comment on Long Work Hours Associated With Increased Stroke Risk

Do you routinely work more than 10 hours a day at your job? Uh-oh. A large study conducted in France found that individuals working long hours had a 29% greater risk of stroke, and those working long hours for 10 years or more had a 45% greater risk of stroke. What exactly are long working hours? The study defined long working hours (LWH) as working more than 10 hours daily for at least 50 days per year.

The researchers looked at people who had full-time jobs, and did not separate out types of strokes - both ischemic and hemorrhagic strokes were lumped together in this study. Another interesting finding was that the risk for stroke was greater among people under the age of 50 who reported long working hours for more than 10 years. And this association had a "lower effect for owners, chief executive officers, professionals, and farmers" - all occupations where people had greater control over decisions during their days.

Studies from other countries found a similar association. For example, in Japan, 60% of death from over-work (called karoshi) cases who received worker compensation died of stroke.

From Science Daily: Long work hours associated with increased risk of stroke  ...continue reading "Long Work Hours Associated With Increased Stroke Risk"

Published on Leave a comment on New Neurons Form In the Brains Of Older Adults

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"

Published on Leave a comment on Is A Poor Sense of Smell In Older Adults A Sign of Deteriorating Health?

A number of studies have found that a poor sense of smell in older adults is linked to health problems (especially Parkinson's disease and dementia) and death. Now a recent study found that a poor sense of smell in older adults is associated with an almost 50% increase in their risk of dying within 10 years—especially in individuals reporting good health. In other words, a poor sense of smell is an early sign of deteriorating health, even when it is not apparent yet to the person.

Researchers at  the Michigan State Univ. College of Human Medicine  followed 2,289 persons (aged 71 to 82) for 13 years. The generally healthy persons took a smell test of 12 common odors (e.g. onion, soap, gasoline, lemon, chocolate and rose) at the start of the study, and were scored as having good, moderate, or poor sense of smell. After 13 years 1,211 of them had died. The researchers then looked to see if there was any association between scores on the smell test and their risk of death at various points over the 13 years.

No association was found at the three- or five-year mark of the study. But those with a poor sense of smell had a 46 percent higher risk of dying by 10 years and a 30 percent higher risk by 13 years, when compared with the older adults with a good sense of smell. The researchers believe the risk was lower at 13 years because so many of the participants had already died - whether their ability to smell was initially good or poor. So how to interpret the study results? It appears that a poor sense of smell may be a sensitive early sign of deteriorating health, even when it is not apparent yet.

From Medical Xpress: Poor sense of smell associated with nearly 50 percent higher risk for death in 10 years  ...continue reading "Is A Poor Sense of Smell In Older Adults A Sign of Deteriorating Health?"

Published on Leave a comment on Light Physical Activity Is Beneficial to the Brain

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"

Published on Leave a comment on Another Reason To Eat Nuts Frequently

Another study found benefits from eating nuts - this time an association between frequently eating nuts and better brain functioning in older adults. The study was done in China and was part of a long-term nutrition and cognitive function study of 4822 adults (aged 55+ years). With aging, it is normal to have some decline in brain functioning, but the researchers said that high nut consumers had much less decline - that the more nuts consumed, the less decline (an inverse relationship).

The article below makes some grand claims ("could improve their cognitive function by up to 60 per cent") for a study that found an association between long-term nut consumption of more than 10 grams (about 1/8 cup) daily and cognitive health, but this doesn't prove it. Perhaps people who eat nuts also eat other foods or do other things that are beneficial for brain functioning. But ... the good news is that eating nuts frequently appears to be beneficial. So eat and enjoy.

By the way, peanuts are not nuts - they are legumes (also beans and peas) - but they have numerous health benefits, and were counted as nuts in this study. Common tree nuts are cashews, almonds, walnuts, hazelnuts, pecans, macadamia nuts, pine nuts, pistachios, chestnuts, lichee nuts, and Brazil nuts. [See all posts on health benefits of nuts.]

From Science Daily: A nutty solution for improving brain health

Long-term, high nut consumption could be the key to better cognitive health in older people according to new research from the University of South Australia.  ...continue reading "Another Reason To Eat Nuts Frequently"

Published on Leave a comment on Birth, Cord Clamping, and Some Microbial Differences

Today's topic: BIRTH. Two recent studies have results that question some current medical practices, which are when to cut the umbilical cord, and hospital vs home birth differences in the baby's gut microbes.

The first study makes a case against the current practice of cutting the umbilical cord immediately after birth. University of Rhode Island researchers found that delaying umbilical cord clamping for more than 5 minutes transfers iron rich blood from the placenta to the baby (resulting in about a 30% increase in blood volume). This resulted in babies at 4 months of age having higher iron storage (ferritin) levels and increased brain myelination. Myelin is a fatty material that wraps around nerve cell fibers - think of it as insulation of the brain's wiring.

The second study found that birth at home results in a more diverse microbiome (microbial community) in the baby at birth and one month later - when compared to babies born in hospitals. This study was conducted in the Hudson Valley region of NY state. All babies were born vaginally and were breastfed. Hospital born babies had decreased levels of some bacteria and increased levels of other bacteria (e.g. Clostridium - with other studies finding that higher levels in children is associated with an increased risk of asthma). It was suggested that certain hospital practices may be causing this (sterile drapes, antibiotics, etc.). 

From Medical Xpress: Study shows benefits of delayed cord clamping in healthy babies

A five-minute delay in the clamping of healthy infants' umbilical cords results in increased iron stores and brain myelin in areas important for early-life functional development, a new University of Rhode Island nursing study has found.  ...continue reading "Birth, Cord Clamping, and Some Microbial Differences"

Published on Leave a comment on Can A Person Get Chronic Wasting Disease From Eating Infected Meat?

The horrible disease called chronic wasting disease (CWD) is spreading among deer, moose, and elk throughout the US and Canada, and reindeer in Norway. This prion disease is similar to "mad cow disease" (bovine spongiform encephalopathy) in cattle, scrapie in sheep and goats, or Creutzfeldt-Jakob disease in humans.  In CWD the brains become progressively like sponges - riddled with holes, along with deterioration in brain function, behavioral changes, and eventually death. Especially worrisome is that it is an infectious disease.

The Centers for Disease Control (CDC) reported in January 2019 that chronic wasting disease has been reported in deer, moose, and elk across 26 US states and 3 Canadian provinces - in both free ranging herds and also some captive herds (such as in ranches and game farms). The following excerpts are from the  CDC site on Chronic Wasting Disease (CWD):

Chronic wasting disease (CWD) is a prion disease that affects deer, elk, reindeer, sika deer and moose. It has been found in some areas of North America, including Canada and the United States, Norway and South Korea. It may take over a year before an infected animal develops symptoms, which can include drastic weight loss (wasting), stumbling, listlessness and other neurologic symptoms. CWD can affect animals of all ages and some infected animals may die without ever developing the disease. CWD is fatal to animals and there are no treatments or vaccines.

To date, there have been no reported cases of CWD infection in people. However, animal studies suggest CWD poses a risk to some types of non-human primates, like monkeys, that eat meat from CWD-infected animals or come in contact with brain or body fluids from infected deer or elk. These studies raise concerns that there may also be a risk to people. Since 1997, the World Health Organization has recommended that it is important to keep the agents of all known prion diseases from entering the human food chain.  ...continue reading "Can A Person Get Chronic Wasting Disease From Eating Infected Meat?"

Published on Leave a comment on Aerobic Exercise, Thinking Skills, and 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"

Published on Leave a comment on Periodontal Disease Link to Alzheimer’s Disease?

In the last few years a number of researchers have suggested that microbes may be triggering or somehow causing Alzheimer's disease. Various microbes have been suggested, and research is finding links with herpes viruses, fungi, other microbes, and gum disease (periodontal disease) microbes. Now another study proposes that the common bacteria Porphyromonas gingivalis - which causes chronic periodontal disease, is linked to the development of Alzheimer's disease.

Researchers have suggested that during an initial infection, the "infectious agent" (viruses, etc.) reaches the central nervous system and brain, then stays there in latent form (inactive) for years. And then when the immune system declines with age (which is a normal part of aging) - the microbes (virus, fungi, etc.) become reactivated and cause inflammation and the chain of events leading to Alzheimer's disease.

Note that in the recent study implicating P. gingivalis - the Cortexyme, Inc. company is doing the research and they, of course, are developing a product - so beware of bias. Also, the research done so far is in the earliest stages. But...it is exciting to see if further research (from them and from others) supports some sort of microbe, or several types of microbes, behind the development of Alzheimer's disease. Will we find that there is an "infectious cause" of Alzheimer's disease ("infection-induced neuroinflammation")? Because this means that there is a way to prevent or treat Alzheimer's disease - some sort of antimicrobial, antibiotic, antiviral, or antifungal. Stay tuned for further research.... From Medical Xpress:

Bacterial pathogen Porphyromonas gingivalis may contribute to Alzheimer's disease: Study

Cortexyme, Inc., a privately held, clinical-stage pharmaceutical company developing therapeutics to alter the course of Alzheimer's disease (AD) and other degenerative disorders, today announced publication of a foundational paper supporting its approach in Science Advances. In the paper, an international team of researchers led by Cortexyme co-founders Stephen Dominy, M.D. and Casey Lynch detail the role of a common bacterium, Porphyromonas gingivalis (Pg), in driving Alzheimer's disease pathology, and demonstrate the potential for small molecule inhibitors to block the pathogen.  ...continue reading "Periodontal Disease Link to Alzheimer’s Disease?"