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 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
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.
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.
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.
It is fairly well established that diabetes and high blood sugar are serious risk factors for Alzheimers (see Alzheimer’s Linked To Sugar & Diabetes and also: Diabetes and Alzheimer’s linked, Alzheimer’s disease
and diabetes, and research review: Type 2 Diabetes as a Risk Factor for Alzheimer’s Disease: The Confounders, Interactions, and Neuropathology Associated With This Relationship)
So it would seem to be great news that the use of an established drug for treating human diabetes might also directly treat Alzheimer’s or at least the symptoms thereof in mice models. However this snarky, but all-too-true, comment from Hacker News summarizes the situation:
This would be great news if we [had] not cured mice many times before of Alzheimer’s. Unfortunatly all the drugs that have worked in mice failed when tested in humans.
Of course, this might be the magic time. Since the drug is already approved for human use, we’ll find out much sooner whether it works for Alzheimer’s. Here are four media articles about the work (all with similar titles):
A Diabetes Drug Has ‘Significantly Reversed Memory Loss’ in Mice With Alzheimer’s
Diabetes drug ‘significantly reverses memory loss’ in mice with Alzheimer’s
Diabetes drug ‘significantly reverses memory loss’ in mice with Alzheimer’s
Diabetes drug “significantly reverses memory loss” in mice with Alzheimer’s
And here is the original research article:
Neuroprotective effects of a triple GLP-1/GIP/glucagon receptor agonist in the APP/PS1 transgenic mouse model of Alzheimer’s disease
The three links in the first paragraph have been added to Risk Factors. The links regarding the diabetes drug have been added to Treatment > Drugs.
A new longitudinal investigation studied 5,189 people over 10 years. It found that people with high blood sugar had a faster rate of cognitive decline than those with normal blood sugar. This was true whether or not their blood-sugar level technically made them diabetic. In other words, the higher the blood sugar, the faster the cognitive decline.
Below are three media articles about the study:
The Startling Link Between Sugar and Alzheimer’s
Faster Cognitive Decline Tied to Hyperglycemia
Diabetes link to long-term mental decline
And here is a link to the formal study itself:
HbA1c, diabetes and cognitive decline: the English Longitudinal Study of Ageing
These four links have all been added to Health > Diet and Alzheimer’s > Risk Factors.
Disturbed sleep is widely regarded as one of the characteristics of Alzheimer’s disease. So there is an obvious question: Are any forms of disturbed sleep occurring before the onset of Alzheimer’s predictive of the later onset of the disease? Four studies set out to examine the relationship between different aspects of sleep disturbance and the later onset of Alzheimer’s. All of the studies showed some correlation between the studied aspect of sleep disturbance and the latter occurrence of Alzheimer’s.
Below, we provide links to a media article on each of the studies, together with a link to the main research article (or an abstract):
A Change in Sleep Habits from Normal to Long: Harbinger of Dementia?
Prolonged sleep duration as a marker of early neurodegeneration predicting incident dementia.
Can poor sleep lead to Alzheimer’s?
Sleep architecture and the risk of incident dementia in the community
Poor Sleep Tied to Increased Alzheimer’s Risk
Poor sleep is associated with CSF biomarkers of amyloid pathology in cognitively normal adults
Poor quality sleep could increase Alzheimer’s risk, research suggests
Slow wave sleep disruption increases cerebrospinal fluid amyloid-β levels
All of the links have been added to Alzheimer’s > Risk Factors.
Can breathing lead to Alzheimer’s? Three studies of the link between air pollution and dementia suggest that it could. Exceedingly small polluting particles — 200 times smaller than the width of a human hair — of ammonium, black carbon, nitrate, sulfate, and heavy metal are known to cause or exacerbate asthma, lung cancer, heart disease — and now — dementia, including Alzheimer’s.
Here is a link to a Science Magazine article discussing two of the studies and the general broad problem:
THE POLLUTED BRAIN: Evidence builds that dirty air causes Alzheimer’s, dementia
Below are links to groups of media articles discussing each study, each together with a link to the research article.
Can Air Pollution Heighten Alzheimer’s Risk?
Air pollution may lead to dementia in older women
Particulate air pollutants, APOE alleles and their contributions to cognitive impairment in older women and to amyloidogenesis in experimental models
Living near heavy traffic increases risk of dementia, say scientists
Living close to a major roadway could increase dementia risk, study says
Living near major roads and the incidence of dementia, Parkinson’s disease, and multiple sclerosis: a population-based cohort study
Culprit hidden in plain sight in Alzheimer disease development
Markers associated with Alzheimer’s and Parkinson’s diseases are present in Mexico City children chronically exposed to concentrations of fine particulate matter PM2.5 above the current EPA USA standards
All of the links can be found in Alzheimer’s > Risk Factors.