Category Archives: Risk Factors

Gum Disease And/Or Herpes: Alzheimer’s Culprits?

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Science doesn’t always proceed linearly straight-forward. Quite often, it zigs and zags between competing hypotheses which can even be contradictory. Evidence is beginning to accumulate that this may indeed be the case with Alzheimer’s research. For over thirty years, from the early 1980’s, the dominant hypothesis has been that the accumulations of amyloid and tau protein plaques found in the brains of Alzheimer’s patients are abnormal and are the cause of the mental decline of those patients. So research focused on how to directly halt or mitigate the growth of those plaques, and that work has been strikingly disappointing. Quite large amounts of money have been invested in attempting to develop drugs which function directly against the plaque accumulation, yet none have been successful in human trials.

The hypothesis that there might be an external physical cause for the plaque accumulation, that there might be a bacterial or viral agent prompting the amyloid and tau accumulations, that the plaque accumulations might actually be a way the brain fights back against certain invaders, was regarded a heresy. But now there is developing evidence that there might be one or two or even more invading agents against which the brain attempts to fight back with the amyloid and tau plaques. (For the story of one of the herpes researchers, see How an outsider in Alzheimer’s research bucked the prevailing theory — and clawed for validation.)

We posted earlier (Herpes & Alzheimer’s and Herpes & Alzheimer’s — More) about studies strongly suggesting that the Herpes virus may be one of the causative agents. Separately, other studies (Periodontitis is associated with cognitive impairment among older adults: analysis of NHANES-III and
Inflammation and Alzheimer’s disease: Possible role of periodontal diseases
) have suggested Periodontal diseases as similar agents. Now a new study strongly suggests that this may indeed be the case.

Here are four media articles about the newest work:
We may finally know what causes Alzheimer’s – and how to stop it
DEMENTIA AND GUM DISEASE: ALZHEIMER’S LINKED TO GINGIVITIS
Gum Disease Bacteria Found in Alzheimer’s Brains
How gum disease could lead to Alzheimer’s

And here is the research report on the work:
Porphyromonas gingivalis in Alzheimer’s disease brains: Evidence for disease causation and treatment with small-molecule inhibitors

All links have been added to Alzheimer’s > Risk Factors and Neuro-Psych

Mild Cognitive Impairment Risk: Lowering Blood Pressure Can Help

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Mild cognitive impairment (MCI) is the precursor stage to serious dementia. It can involve problems with memory, language, thinking and judgment. These problems are more substantial than the ordinary normal age-related mental changes. It’s well known that if you have high blood pressure, it is very beneficial to your heart to lower it, perhaps dramatically, to a systolic blood pressure less than 120 mmHg. A new study shows that such lowering can also measurably reduce the risk of MCI.

Here are six media articles on the work:
Lowering blood pressure may help cut risk of early dementia, study finds
Lowering blood pressure could cut risk factor for dementia
Mild cognitive impairment: Reducing blood pressure can lower risk
Treating high blood pressure could reduce risk of memory issues, study finds
Study Offers Hint of Hope for Staving Off Dementia in Some People
Major New Study Finds Lowering Blood Pressure Can Prevent Cognitive Decline, but Questions Remain
Here is the National Institutes of Health press release on the study:
Does intensive blood pressure control reduce dementia?

Here is a link to the study itself:
Effect of Intensive vs Standard Blood Pressure Control on Probable Dementia

All links have been added to Alzheimer’s > Amelioration/Prevention and Alzheimer’s > Risk Factors.

Air Pollution: Shorter Life, More Dementia Risk, Worse Thinking

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Three recent studies have demonstrated that breathing polluted air has significant negative effects, including a shorter lifespan, greater risk of dementia, and diminished cognitive capacity.


Life Expectancy
Airborne PM(Particulate Matter)2.5 is material less than 2.5 micrometers, which can be seen only with electron microscopes. Being so small, they can travel deeply into our lungs with quite harmful effects. They are produced from car & truck exhausts, industrial plants include coal-fired powerplants, and also include dust produced by windstorms. Averaged across the globe, breathing them typically cuts up to a year off lifespans, and in areas of greater pollution, up to two years.

Here are three links to media articles on the work:
Air pollution reduces global life expectancy by more than one year
Air pollution is shaving a year off our average life expectancy
Lowering air pollution just a bit would increase life expectancy as much as eradicating lung and breast cancer

Here is the research publication:
Ambient PM2.5 Reduces Global and Regional Life Expectancy
These links have been added to Aging


Dementia Risk

This study involved a sample of 130,978 adults living in London between 2005 and 2013. The participants were between 50 and 79 years old. Broadly, even after making adjustments for factors such as smoking and social status/class, those from the most polluted areas of London were much more at risk of dementia (40% more) than those from the least polluted areas.

Here are two links to media articles on the research:
Is air pollution tied to higher dementia risk?
Air pollution linked to much greater risk of dementia

Here is the research publication:
Are noise and air pollution related to the incidence of dementia? A cohort study in London, England


Diminished Cognitive Capacity
Living with air pollution very likely reduces your intelligence, as measured by test scores for arithmetic and language. The effect can, on average, be as if one had lost a year of education. For people over 64, for men, and for those with lower education, the effect can be even greater.

An international research team carried out the research in China using 20,000 people, between 2010 and 2014. People who were exposed longer to polluted air had greater damage to their intelligence. Language ability was hurt more than mathematical ability, and men were harmed more than women.

Here are three links to media articles on the research work:

Air Pollution Exposure Harms Cognitive Performance, Study Finds
Study shows air pollution may be causing cognitive decline in people

Here is the research publication:
The impact of exposure to air pollution on cognitive performance

The last two groups of links have been added to Alzheimer’s > Risk Factors

Your Heart And Your Brain

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One is in your head, the other in your chest. But of course they’re deeply interconnected. Looking at it from your brain’s point of view, what’s good for your heart is also good for your head. A major French study reported in August quantifies that, using the American Heart Association (AHA)’s notion of Life’s Simple 7:

Blood pressure
Blood sugar
Cholesterol
Diet
Exercise
Smoking status
Weight management

The better one manages each of these, the lower one’s risk of dementia.

Here are links to media articles about heart health and dementia:
The more you do to promote your cardiovascular health, the lower your risk of dementia
Midlife heart health shows a link with future risk of dementia
Better heart health may mean lower dementia risk in older people
These 7 heart-healthy factors could cut your risk of dementia, a new study finds

Here are two health organization posts on heart health and dementia:
Dementia and Heart Health: Are They Related?
Risk factors for heart disease linked to dementia

Research article:
Association of Cardiovascular Health Level in Older Age With Cognitive Decline and Incident Dementia

All links have been added to Aging, Alzheimer’s > Amelioration/Prevention and Alzheimer’s > Risk Factors

Your Brain On Alcohol

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No definitive smoking gun on alcohol use has yet been presented, but the evidence leans heavily against it. Two very large direct studies and one huge meta study have recently appeared, and they largely point to increased risk of dementia as well as of cardiometabolic disease (includes stroke, coronary heart disease, and diabetes).

Media articles:
No healthy level of alcohol consumption, says major study
There’s no risk-free amount of alcohol, population-level study finds
Study:
Alcohol use and burden for 195 countries and territories, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016

Media articles:
Heavy Drinking Tied to Early-Onset Dementia in French Study
Study:
Contribution of alcohol use disorders to the burden of dementia in France 2008–13: a nationwide retrospective cohort study.

Media article:
Both long term abstinence and heavy drinking may increase dementia risk
Editorial:
Relation between alcohol consumption in midlife and dementia in late life (Editorial)
Study:
Alcohol consumption and risk of dementia: 23 year follow-up of Whitehall II cohort study

All of the links have been added to Alzheimers > Risk Factors and Health > Diet

Herpes & Alzheimer’s — More

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Earlier this month, we described a study demonstrating a link between the presence of certain herpes viruses in the brain, and the presence of Alzheimer’s signs. Interestingly, three more studies of this connection have appeared. All three confirm this connection, but the third in addition suggests that aggressive treatment with herpes anti-viral medication can significantly reduce the chance of encountering dementia. However, the study did not attempt to deal with people who had already encountered dementia.

Here are two media articles:
Herpes linked to Alzheimer’s: Antivirals may help
Alzheimer’s risk 10 times lower with herpes medication

Here is an interesting scientific commentary by two researchers active in the area (referenced in both media articles linked above):
Herpes Viruses and Senile Dementia: First Population Evidence for a Causal Link

Here are links to the first two research studies
Increased risk of dementia following herpes zoster ophthalmicus
Epidemiology and long-term disease burden of herpes zoster and postherpetic neuralgia in Taiwan: a population-based, propensity score-matched cohort study

Here is the abstract of the third research article which provides information that “The usage of anti-herpetic medications in the treatment of HSV infections was associated with a decreased risk of dementia”:
Anti-herpetic Medications and Reduced Risk of Dementia in Patients with Herpes Simplex Virus Infections-a Nationwide, Population-Based Cohort Study in Taiwan.

All links have been added to Alzheimer’s > Risk Factors and Alzheimer’s > Neurology & Neuroplasticity

High Blood Pressure In Older People Raises Alzheimer’s Risk

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High blood pressure is known to lead to heart attack/failure, stroke, and kidney disease or failure, among other bad consequences. Now, a recently reported study shows that high blood pressure appears to be linked to higher risk of (silent)infarcts (brain lesions/dead brain tissue) and a higher number of Alzheimer’s tangles (but not plaques — yet), and overall, a higher risk of Alzheimer’s. The study group consisted of nearly 1,300 individuals — 2/3 of whom had high blood pressure — followed for an average of 8 years before their deaths, after which their brains were autopsied to determine the effects of the high blood pressure. Yet another reason to attempt to manage hypertension.

Links to media articles about the work:
Blood pressure linked to lesions, signs of Alzheimer’s in autopsied brains
High blood pressure may increase dementia risk
High blood pressure threatens the aging brain, study finds
Late-Life BP Tied to Brain Infarcts, Tangles
Here is a link to the research article:
Late-life blood pressure association with cerebrovascular and Alzheimer disease pathology

All links have been added to Alzheimer’s > Risk Factors

Diabetes, Obesity, & The Brain

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There is very substantial evidence that Type 2 Diabetes significantly raises the odds that one will develop Alzheimer’s or other forms of dementia. Here are some presentations:

Connections Between Diabetes and Alzheimer’s Disease
Diabetes and Alzheimer’s linked
Alzheimer’s Disease & Diabetes
How Diabetes Affects Your Brain

There is also strong evidence that being overweight or obese raises the odds that one will develop Type 2 diabetes. Here are some articles:

How Obesity Increases The Risk For Diabetes
Adult obesity and type 2 diabetes
Diabetes and Obesity

Just being overweight, without diabetes, can still have effects on the brain:
Brains of overweight people look ten years older than those of lean peers

And being overweight together with having diabetes further affects your brain:
Diabetes, weight can combine to alter brain, study says

All the links above have been added to Alzheimer’s > Risk Factors.

Category: Risk Factors

Diet Soda And Dementia And Stroke

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Just about a year ago, a study examining the associations of drinking artificially sweetened soda drinks made something of a splash. The study found that people consuming at least a can of so-called diet drinks every day were 2.96 times more likely to suffer an ischaemic stroke and 2.89 times more likely to develop Alzheimer’s disease than those who drank them less than once a week. The study — like many — could not establish a causal relationship either way, only a definite association. But “the best current evidence suggests that when it comes to reducing your risk of dementia, what is good for your heart is also good for your head.”

Here are four media articles about the work:
Stroke and dementia risk linked to artificial sweeteners, study suggests
Diet sodas may be tied to stroke, dementia risk
Is soda bad for your brain? (And is diet soda worse?)
Diet Soda and Dementia: What You Need to Know
Here is a link to the research publication:
Sugar- and Artificially Sweetened Beverages and the Risks of Incident Stroke and Dementia
And here is a link to a collection of expert researcher reactions to the publication:
expert reaction to artificially-sweetened fizzy drinks, stroke and dementia

The links have all been added to Alzheimers > Risk Factors and Health > Diet.

Too Many Hours Sitting Shrinks A Brain Memory Area

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The medial temporal lobe (MTL) includes the hippocampus, and is essential to the processing and storage of long-term memories. Recent research demonstrates that in people over 45, the number of hours spent sitting per day is inversely related to the thickness of the MTL. Crudely put, too many hours sitting can reduce your ability to remember. Since it is already known that sedentary behavior is linked to an increased risk of heart disease, diabetes and premature death in middle-age and older adults, this most recent work adds another disturbing element to the argument against sitting too much.

While the research appears to show that physical activity, even at high levels, is insufficient to offset the harmful effects of sitting for extended periods, the work is preliminary in that the study focused on hours spent sitting, and did not take into consideration whether participants took breaks during long stretches of sedentary behavior. The researchers said that this could be a limitation of their results.

Here are links to two media articles on the work:
Sitting Too Much Can Change Your Brain & Impact Your Memory, A New Study Says
Too Much Sitting May Shrink the Part of Your Brain Tied to Memory
Here is a link to the research article:
Sedentary behavior associated with reduced medial temporal lobe thickness in middle-aged and older adults

All the links have been added to Aging, Physical Exercise, and Alzheimers > Risk Factors.