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Human brains are getting larger each decade. That's the conclusion of researchers conducting the large Framingham Heart study which has now gone on for 75 years.

Between 1999 and 2019 the researchers conducted MRIs on participants born from the 1930s to the 1970s, with participants having an average age of 57. They found that each decade the brain volume steadily increased, with the brains of people born in the 1970s having 6.6% more volume than those born in the 1930s. Brain surface area increased about 15% in that time.

Brain structures such as white matter, gray matter, and hippocampus (a brain region involved in learning and memory) also increased in size over time. This increase in brain volume clearly shows that environmental factors (e.g., nutrition, education, social), and not just genetic factors, influence brain size.

The researchers thought that a larger brain volume, which signifies brain health,  might be protective against Alzheimer's disease. And that this could explain why the percentage of people (the incidence) of Alzheimer's disease and dementia has gone down over time.

From Medical Xpress: Human brains are getting larger: That may be good news for dementia risk

A new study by researchers at UC Davis Health found human brains are getting larger. Study participants born in the 1970s had 6.6% larger brain volumes and almost 15% larger brain surface area than those born in the 1930s. ...continue reading "Human Brains Are Getting Larger Over Time"

For a while now it has become clear to some scientists that the prevailing view of Alzheimer's disease (buildup in the brain of 2 substances: amyloid and tau) isn't correct. Instead, some researchers feel that there is growing evidence that viruses are implicated as a cause of Alzheimer's and other neurodegenerative diseases (e.g., vascular dementia, ALS, Parkinson's disease, multiple sclerosis).

A recent study linked 22 viruses to the development of Alzheimer's disease and other neurodegenerative diseases (e.g., vascular dementia, ALS, Parkinson's disease, multiple sclerosis) within 15 years. The strongest association was for viral encephalitis and later developing Alzheimer’s diseaseInfluenza with pneumonia was associated with 5 neurodegenerative diseases.

The researchers also found a link between infection with Epstein Barr and later developing multiple sclerosis (this confirmed other recent research).

Other studies find that vaccinations (influenza, pneumonia, shingles) are associated with lower rates of Alzheimer's disease. This has also been found with antivirals (e.g., for herpes simplex).

From Science Alert: A Study of 500,000 Medical Records Links Viruses to Alzheimer's Again And Again

A study of around 500,000 medical records suggested that severe viral infections like encephalitis and pneumonia increase the risk of neurodegenerative diseases like Parkinson's and Alzheimer's. ...continue reading "Study Finds Link Between Viruses and Alzheimer’s Disease"

Choline appears to be a neglected nutrient. It is essential for healthy brain functioning, yet researchers of a recent study say the great majority of us do not get the recommended daily intake of choline in our diet. They suggest that this could be causing harm to our health, including the brain.

They also pointed out that since eggs and meat are the best dietary source, people on restricted or vegan diets are especially at risk of a choline deficiency. It is not found in most multivitamins.

The  Arizona State Univ. researchers found that choline deficiency is involved with multiple health problems throughout the body (e.g., inflammation, insulin production, cardiovascular disease, brain function) and even Alzheimer's disease. Their study was conducted on mice, but they felt similar processes occurred in humans.

Good dietary sources of choline: eggs, meat, dairy products, poultry, and fish. Lower amounts are in nuts, beans, potatoes, and cruciferous vegetables (e.g., broccoli).

Related to all this is that one should also try to lower intake of anti-cholinergic medications, if possible. Studies find that their use is linked to cognitive decline and dementia - they block the action of the brain neurotransmitter acetylcholine (which is produced by choline).

Excerpts from Science Daily: Study explores effects of dietary choline deficiency on neurologic and system-wide health

Choline, an essential nutrient produced in small amounts in the liver and found in foods including eggs, broccoli, beans, meat and poultry, is a vital ingredient for human health. A new study explores deficiency in dietary choline adversely affects the body and may be a missing piece in the puzzle of Alzheimer's disease.  ...continue reading "The Nutrient Choline Is Necessary For Brain Health"

Fabulous news for those persons wanting to reduce their risk of Alzheimer's disease as they age - get a flu vaccine, especially annually. A recent large study found that with each annual vaccine received in adults 65 years and older, the protective effect increases. That's it! So simple.

The study authors compared 935,887 flu-vaccinated patients and 935,887 non-vaccinated patients. At the start of the study, no one had an Alzheimer's diagnosis. They found a 40% lower risk of an Alzheimer's diagnosis in those receiving flu vaccines compared to individuals not receiving a flu vaccine in the following 4 years.

Other studies have had similar findings, as well as that getting other vaccines in adulthood also reduce the risk of dementia, such as pneumonia, tetanus, polio, and herpes vaccines. Current thinking is that this protective effect from vaccines is due to their immunological effects - that they boost the immune system in a good way.

From Science Daily: Flu vaccination linked to 40% reduced risk of Alzheimer's disease

People who received at least one influenza vaccine were 40% less likely than their non-vaccinated peers to develop Alzheimer's disease over the course of four years, according to a new study from UTHealth Houston. ...continue reading "The Flu Vaccine is Linked to a Lower Risk of Developing Alzheimer’s Disease"

Something surprising - having cancer is linked to a lower risk of Alzheimer's disease and a lower risk of neurodegenerative symptoms (e.g., memory loss) during their lifetimes.

One big analysis and review of 22 studies (representing more then 9.6 million people!) calculated that cancer diagnoses are associated with 11% reduction in Alzheimer's disease occurrence. However, this relationship does not hold true for melanoma. [Also, there is a strong positive correlation between melanoma and Parkinson's disease - which is a neurodegenerative condition.]

There are some theories, but it is still unknown why this lower risk of Alzheimer's disease occurs in persons with cancer.

Excerpts from The Scientist: Cancer Tied to Reduced Risk of Alzheimer’s Disease

In recent years, scientists around the world have been probing an unexpected trend: The risk of developing cancer seems to have an inverse relationship with the risk of developing Alzheimer’s disease.  ...continue reading "Reduced Risk of Alzheimer’s Disease In Those With Cancer"

A recent study found that eating higher levels of foods with flavonoids (e.g. berries, apples, and tea) may lower the risk of later development of Alzheimer's disease and other age-related dementias.

Since currently there are no effective drugs that prevent or actual medical treatments for dementia, it is great that what a person eats (the dietary pattern) long-term may be protective. Something we can do to lower our risk for Alzheimer's disease and other dementias!

Tufts University researchers followed 2801 persons (50 years and older) for 20 years and found that those with the lowest intake of flavonoid rich foods (especially 3 flavonoid classes: flavonols, anthocyanins, and flavonoid polymers) had a 20 to 40% higher chance of developing Alzheimer's disease and other dementias, when compared to those eating the most flavonoid rich foods. [Note: The lowest intake group averaged  about 1 1/2 apples, but no berries or tea per month.]

Flavonoids are naturally occurring bioactive pigments, of which there are 7 types, that are found in plant-based foods. Some good sources of different types of flavonoids include berries & red wine (anthocyanin rich), onions & apples, pears (flavonol rich), citrus fruits and juices, teas, dark chocolate, parsley, celery,and soy products.

Eating a variety of fruits and vegetables appears to be best for health benefits. There is no one super-food. Other studies also find that the Mediterranean diet, which emphasizes fruits and vegetables (thus flavonoid rich), may reduce the risk of cognitive decline and dementia, including Alzheimer's disease.

Why are flavonoid containing foods protective, specifically "neuroprotective"? Studies suggest that they do the following: antioxidant effects, protect neurons from neurotoxins and combat neuroinflammation, and favorable changes in brain blood flow,

Excerpts from Science Daily: More berries, apples and tea may have protective benefits against Alzheimer's

Older adults who consumed small amounts of flavonoid-rich foods, such as berries, apples and tea, were two to four times more likely to develop Alzheimer's disease and related dementias over 20 years compared with people whose intake was higher, according to a new study led by scientists at the Jean Mayer USDA Human Nutrition Research Center on Aging (USDA HNRCA) at Tufts University.  ...continue reading "Eating More Fruits and Berries Lowers Risk of Dementia"

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?"

New research is published every day, but only some studies are big research stories or game-changers. The following are what I consider some of the most memorable studies of 2018 – some in a good way, but some of the others have left me with a sense of horror. I think there will be follow-up research, so keep an eye out for more on these important topics.

Are we heading toward a time in the not so distant future when all men are infertile? (Due to exposure to all the endocrine disruptors around us.) Will All Men Eventually Be Infertile? This was posted September 5, 2018.

Researchers are now seriously investigating and finding evidence that microbes may be causing Alzheimer’s disease. This approach is rapidly finding support in the medical field, and may lead to possible ways to treat or prevent the disease. Possible Herpes Virus Link to Alzheimer’s Disease was posted July 13, 2018, and Herpes Viruses and Alzheimer's Disease on  June 22, 2018.

Type 2 Diabetes May Be Reversed With Weight Loss was posted August 10, 2018. This study and an earlier similar study from 2016 found that losing over 30 pounds over a short period can reverse type 2 diabetes - 46% in the 2018 study and 60% (in people who had it less than 10 years) in the earlier study.

More and more evidence is accumulating that certain diets are anti-inflammatory. Especially beneficial are diets rich in fruits, vegetables, seeds, nuts, legumes (beans), and whole grains - which also have a lot of fiber. This is exciting research because chronic low-grade inflammation is linked to a number of chronic diseases (heart disease, cancer, etc.). Fruits, Vegetables, and Whole Grains Lower Inflammation – posted August 1, 2018.

[Related to this last topic is one of the most eye-opening studies I have ever read on how what one eats has a quick effect on gut microbes and health of the gut (including inflammation of the colon): Changing Diet Has Big Effect On Colon Cancer Risk – posted April 28, 2015.]

Over the last few decades, the mainstream theory of Alzheimer's disease (amyloid deposits build up in the brain) and medical treatments (drugs) just hasn't led anywhere. Nothing has worked to stop Alzheimer's disease. But evidence is building for an alternative view - that microbes in the brain are leading to the development of Alzheimer's disease (here and here). Now new compelling evidence from studies implicates several strains of herpes virus in Alzheimer's disease. At least one study has suggested herpes zoster, others the common herpes simplex, while other studies suggest other herpes strains. Which means that treatment could perhaps involve anti-viral drugs! (Wouldn't it be great if that works???)

In one study researchers found that human herpes virus DNA and RNA were more abundant in the brains of those diagnosed with Alzheimer's disease and that "abundance correlated with clinical dementia scores" - meaning the more of it, the sicker the person was. And the two viruses they found to be most strongly associated with Alzheimer's, HHV-6A and HHV-7, were not as abundant in the brains of those with other neurodegenerative disorders.

The article mentions another recently published study from Taiwan. This amazing study looked at more than 33,000 individuals in Taiwan and found that patients with herpes simplex infections (HSV) may have a 2.56-fold increased risk of developing dementia. And they found that the use of anti-herpetic (antiviral) medications in the treatment of HSV infections was associated with a decreased risk of dementia - that the risk dropped back down "to baseline". The conclusion was that the antiviral medication reduced the risk of Alzheimer’s by keeping the herpes infection in check. Yes! Finally, a way foreward in this horrible disease.

Scroll down and read what one group of researchers says: "Our model right now is that it’s not just a single microbe, but a disturbance in the brain microbiome that can lead to Alzheimer’s disease.”

From A. Azvolinsky's article at The Scientist: Herpes Viruses Implicated in Alzheimer’s Disease

The brains of Alzheimer’s disease patients have an abnormal build up of amyloid-β proteins and tau tangles, which, according to many researchers, drives the ultimately fatal cognitive disease. This theory is being amended to a newer one, which posits that microbes may trigger Alzheimer’s pathology ...continue reading "Herpes Viruses and Alzheimer’s Disease"

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?"