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Category: brain

Published on Leave a comment on Type 2 Diabetes and the Brain

A recent study adds to the list of health reasons to try to avoid type 2 diabetes if at all possible, such as making lifestyle changes (e.g. lose weight if overweight, improve diet,  exercise). Earlier studies found that the brain atrophies (decreases in volume) with type 2 diabetes, and that the presence of type 2 diabetes doubles the risk of dementia in older age. Yikes!

Similarly, Australian researchers in the recent study found that type 2 diabetes in older individuals is associated with decline in verbal memory and verbal fluency over a five year period, but the findings suggest that this may start in midlife.  This is because at the start of the study those with type 2 diabetes already showed signs of greater brain atrophy than those without type 2 diabetes. The type 2 diabetes group had "poorer cognitive function" at the start of the study, and then they continued to decline over the 5 year study time, but not at any greater rate than individuals without diabetes. In contrast to the decline in verbal fluency over the 5 year period in the diabetes group, the non-diabetes group actually showed an slight increase in verbal fluency each year.

Of the 705 persons in the study, the average age of the type 2 diabetes group was 68.2 years, while the non-diabetes group was 72.5 years - so can see that the diabetes group was generally younger. [Note that the brain shrinks a little as we age, and it's a normal part of aging, but you want to minimize it. The more "youthful" the brain, the better for cognitive functioning.] 

From Science Daily: In older people, type 2 diabetes is associated with a decline in brain function over 5 years, study shows

New research published in Diabetologia (the journal of the European Association for the Study of Diabetes [EASD]) shows that in older people living in the community, type 2 diabetes (T2D) is associated with a decline in verbal memory and fluency over 5 years.  ...continue reading "Type 2 Diabetes and the Brain"

Published on Leave a comment on Are Bacteria Living In Healthy Brains?

Are bacteria living in healthy human brains? It has long been thought that the brain is protected by the blood-brain barrier, that the brain is sterile (bacteria are not normally there), and if there are bacteria in the brain, then that means a serious disease (e.g. meningitis).  However, the research team of Rosalind Roberts, Charlene Farmer, and Courtney Walker (at the University of Alabama) found bacteria in the brains they studied with electron microscopes.

The brains showed no inflammation (thus the bacteria were not pathogenic), and modern tests (genetic sequencing) showed that they were gut bacteria. Which  means they got there from the gut. If further research supports their findings, then this would be a paradigm shift -  a new way of thinking about the brain and microbes.

Two good articles discuss this research - the first is in Science, and the second is a fascinating interview of Rosalind Roberts about this research. Excerpts from the article written by Michael Segal in Nautilus:

Are There Bacteria in Your Brain?

...continue reading "Are Bacteria Living In Healthy Brains?"

Published on Leave a comment on Eat Fruits And Vegetables Every Day!

Another reason to eat fruits and vegetables daily - cognitive and memory functioning in later life. A large US study of 27,842 men found that a higher intake of fruits, vegetables, and orange juice for many years is linked to a lower risk of poor cognitive functioning in later years of life (70s and beyond). The study specifically looked at subjective cognitive function - a measure of earliest changes in cognitive functioning, including memory. This is the stage before "mild cognitive impairment". The study started in 1986 when the average age was 51 years, and continued till 2012. The men studied were all health professionals (e.g. dentists)

What was a high intake of fruits and vegetables? For vegetables: about 5.7 servings per day (while the lowest intake was 1.7 servings per day). For fruit: high intake was 3.1 servings per day (vs lowest intake was .5 servings per day). For fruit juice (orange juice): high intake was 1.5 servings per day (vs lowest intake was .1 servings per day). A serving of fruit is considered one cup of fruit or ½ cup of fruit juice. A serving of vegetables is considered one cup of raw vegetables or two cups of leafy greens.

The researchers found that green leafy vegetables, carotenoid-rich vegetables (esp. tomatoes and peppers), cantalope, berries, and orange juice to be especially protective. They point out that many antioxidant nutrients and bioactive substances (including vitamins A,B, C, and E, carotenoids, flavonoids, and polyphenols) are all found naturally in vegetables, fruits, and juices. These are thought to reduce brain oxidative stress, improve cognitive performance, and to prevent neuronal damage. In other words, all good things for the brain. From Science Daily:

Orange juice, leafy greens and berries may be tied to decreased memory loss in men

Eating leafy greens, dark orange and red vegetables and berry fruits, and drinking orange juice may be associated with a lower risk of memory loss over time in men, according to a study published in the November 21, 2018, online issue of Neurology, the medical journal of the American Academy of Neurology.  ...continue reading "Eat Fruits And Vegetables Every Day!"

Published on Leave a comment on Appendix Removal and Parkinson’s Disease

A benefit (perhaps) of having the appendix taken out in childhood - it is associated with a lower rate of Parkinson's disease decades later in life, according to an international study that looked at health records of 1.7 million people in Sweden. Other main findings is that this finding is especially strong for individuals living in rural areas (and not urban areas), and that removing the appendix also delayed the age of Parkinson's disease onset in those who got the disease. But if you read further, there were other interesting findings in the study, even though much is still unknown - it's still a big puzzle with lots of pieces still to be filled in.

By the way, other recent research also supports the view that Parkinson's disease gets its start in the gut - and not in the brain, which is what everyone thought for years. But note that there are other risk factors such as certain pesticide exposure or drug use, or trauma to the head that are linked to Parkinson's disease. Many studies find that rural living is associated with a higher risk for Parkinson's disease, and it is thought this is probably due to higher exposure to pesticides, which then somehow contributes to the development of Parkinson's disease. From Medical Xpress:

Appendix removal is linked to lower risk of Parkinson's

Scientists have found a new clue that Parkinson's disease may get its start not in the brain but in the gut—maybe in the appendix. People who had their appendix removed early in life had a lower risk of getting the tremor-inducing brain disease decades later, researchers reported Wednesday.

Why? A peek at surgically removed appendix tissue shows this tiny organ, often considered useless, seems to be a storage depot for an abnormal protein—one that, if it somehow makes its way into the brain, becomes a hallmark of Parkinson's.  ...continue reading "Appendix Removal and Parkinson’s Disease"

Published on Leave a comment on Are You Both A Good Navigator And Have A Good Sense of Smell?

Do you have a good sense of smell and are also good at navigation? A series of studies by Canadian researchers found that they are linked - and that these abilities are located in overlapping brain areas - the orbitofrontal cortex and hippocampus. The Canadian researchers found that both the cortical thickness of the left orbitofrontal cortex and the right hippocampus were bigger in the better smellers and better navigators (the subjects had MRI scans).

The researchers say the findings support the view that olfaction (the sense of smell) evolved to aid navigation - this hypothesis is called the olfactory spatial hypothesis. For example, all animals use chemical cues to navigate, to find food, to avoid being preyed upon, while in contrast vision and hearing are not present in all animals. In humans, good navigators have what the researchers call "spatial memory". From Laura Sanders at Science News:

People who have a good sense of smell are also good navigators ...continue reading "Are You Both A Good Navigator And Have A Good Sense of Smell?"

Published on Leave a comment on What Is Optimal Amount Of Sleep For Our Cognitive Processes?

So many of us seem to not get enough sleep, and then there are those that sleep and sleep. But .. it seems the sweet spot for sleep and our brain health (cognitive performance) is about 7 to 8 hours - at least according to a large study from Canadian researchers at Western University. People reporting typically sleeping 4 hours or less a night had the most impairments in how they performed on a variety of cognitive tests - equivalent to aging 8 years.

Reasoning, verbal skills, and overall cognition were impaired by less than 7 hours or more than 8 hours of sleep. But not short term memory. Actual age of the person made no difference on the results - everyone performed best at 7 to 8 hours of sleep. (Volunteers completed a series of 12 tests online which measured a broad range of cognitive abilities.) By the way, about half of the 10886 persons participating in the study reported typically sleeping 6.3 hours or less a night. Not enough. The good news is that just one night of sleeping a little more than the usual too little had a positive effect on cognitive abilities - thus cognitive improvement. From Science Daily:

World's largest sleep study shows too much shut-eye can be bad for your brain  ...continue reading "What Is Optimal Amount Of Sleep For Our Cognitive Processes?"

Published on Leave a comment on Could Physical Activity Reduce Stroke Severity?

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 strokes. Researchers 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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Published on 2 Comments on Sitting For Long Periods and Reduced Blood Flow To the Brain

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"

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Published on 1 Comment on What Do High Carbon Dioxide Levels In The Air Do To Thought Processes?

This is a topic that is totally neglected: What will it feel like when the carbon dioxide levels in the atmosphere (the air) increase as our climate changes? What kinds of effects will it have on our thought processes (our cognition)? The reason I mention this is because research shows that as carbon dioxide (CO2) levels increase in rooms with people in them, it feels "stuffy" and people's thinking (cognitive processes) deteriorate. They don't think and work as effectively. Air starts to feel "stuffy" at about 600 ppm (parts per million). Our current CO2 levels in outside air are already above 400 ppm, and the levels are forecast to keep rising.

Indoor air typically has much higher CO2 concentrations than outdoor air because people are exhaling CO2 with every breath. (Note that research shows that urban city centers can already have outdoor CO2 levels above 500 ppm due to the “urban CO2 dome” effect, and elementary school classrooms are frequently above 1000 ppm, with some going as high as 3000 ppm at times). So as CO2 levels rise in the atmosphere with climate change, it will lead to even higher indoor CO2 levels in our workplaces, homes, and schools.

So... with increases in CO2 levels, what if it feels "stuffy" all the time? We won't be able to escape the "stuffiness" by going outside or opening a window. And remember, it will be worse in rooms with people in it, or in cars and aircraft. The research shows increasing CO2 levels make it harder to work and think effectively - think of it as an indoor air pollutant. Holy mackerel! This scary aspect of the effects of rising CO2 levels in the atmosphere needs to be widely discussed and addressed.

The following 2 articles discuss the research showing the negative effects on cognition with increases in CO2 levels (what happens to people's mental processes in crowded classrooms, offices, etc.).  ...continue reading "What Do High Carbon Dioxide Levels In The Air Do To Thought Processes?"

Published on Leave a comment on Excitement Builds Over Possible Herpes Virus Link to Alzheimer’s disease

People are excited over the possibility that herpes viruses could be behind Alzheimer's disease and whether it could be prevented with the use of antiviral medication. This is because currently there is no way to prevent or treat the disease.The June 22, 218 post discussed the amazing recently published study done in Taiwan.

The study looked at more than 33,000 individuals and found that those with herpes simplex infections (HSV) had a 2.56-fold increased risk of developing dementia. But individuals that were treated with anti-herpetic (antiviral) medications for a newly diagnosed HSV outbreak had a decreased risk of dementia - that the risk dropped back down "to baseline". [Note that whether it was the person's initial infection or reactivation of an existing infection is unclear.]

The researchers' conclusion was that the antiviral medication reduced the risk of senile dementia (Alzheimer’s disease) by keeping the herpes infection in check. Now studies need to be done to see if this association holds.

But the amazing results, along with studies that also implicate other herpes viruses, led to a commentary being published in the Journal of Alzheimer's Disease about the tantalizing possibility of a simple treatment or prevention - perhaps even a vaccine. This commentary highlights the excitement among some (many?) researchers. The authors of the commentary mention that currently "over 130 studies, using a variety of approaches, support a major role for HSV1 in Alzheimer's Disease".

Even if it's not all cases of Alzheimer's disease, but only a portion - it would still be incredible.

From Science Daily: Herpes linked to Alzheimer's: Antivirals may help

A new commentary by scientists at the Universities of Manchester and Edinburgh on a study by Taiwanese epidemiologists supports the viability of a potential way to reduce the risk of Alzheimer's disease. When the Taiwanese authors looked at subjects who suffered severe herpes infection and who were treated aggressively with antiviral drugs, the relative risk of dementia was reduced by a factor of 10. 
...continue reading "Excitement Builds Over Possible Herpes Virus Link to Alzheimer’s disease"