Alzheimer’s Disease

A twist on the genetic link between Alzheimer’s and heart disease

Julie Corliss
Julie Corliss, Executive Editor, Harvard Heart Letter

Although the two conditions seem unrelated, Alzheimer’s and heart disease actually share a genetic link. People who have a certain gene variant have both a somewhat elevated heart disease risk and a significantly elevated Alzheimer’s risk. Fortunately, a recent study has suggested that when people know they have this variant, they’re more likely to make healthy lifestyle choices that benefit their heart — and what’s good for the heart is good for the brain.

Decline in dementia rate offers “cautious hope”

Beverly Merz
Beverly Merz, Executive Editor, Harvard Women's Health Watch

Last year, the Alzheimer’s Association predicted that rates of dementia would continue to rise. However, a report recently published in the New England Journal of Medicine found that rates of dementia have actually dropped steadily over the past three decades. Whether the drop in rates applies to everyone, and whether it will continue, remain to be seen. But the evidence also confirms that there’s quite a lot you can do to lower your dementia risk.

Editorial calls for more research on link between football and brain damage

Patrick J. Skerrett, Former Executive Editor, Harvard Health

Is brain damage an inevitable consequence of American football, an avoidable risk of it, or neither? An editorial published yesterday in the medical journal BMJ poses those provocative questions. Chad Asplund, director of sports medicine at Georgia Regents University, and Thomas Best, professor and chair of sports medicine at Ohio State University, offer an overview of the unresolved connection between playing football and chronic traumatic encephalopathy, a type of gradually worsening brain damage caused by repeated mild brain injuries or concussions. The big question is whether playing football causes chronic traumatic encephalopathy or whether some people who play football already at higher risk for developing it. The Football Players Health Study at Harvard University hopes to provide a solid answer to that and other health issues that affect professional football players.

Common anticholinergic drugs like Benadryl linked to increased dementia risk

Beverly Merz
Beverly Merz, Executive Editor, Harvard Women's Health Watch

A new report from the University of Washington links long-term use of anticholinergic medications and dementia. Anticholinergic drugs block the action of acetylcholine. This substance transmits messages in the nervous system. In the brain, acetylcholine is involved in learning and memory. In the rest of the body, it stimulates muscle contractions. Anticholinergic drugs include some antihistamines, tricyclic antidepressants, medications to control overactive bladder, and drugs to relieve the symptoms of Parkinson’s disease. The study found that people who used anticholinergic drugs were more likely to have developed dementia as those who didn’t use them. Dementia risk increased with the cumulative dose. Taking an anticholinergic for the equivalent of three years or more was associated with a 54% higher dementia risk than taking the same dose for three months or less. Safer alternatives to anticholinergic drugs exist.

Benzodiazepine use may raise risk of Alzheimer’s disease

Beverly Merz
Beverly Merz, Executive Editor, Harvard Women's Health Watch

Drugs in the benzodiazepine family have long been used to treat anxiety and sleep problems. They can cause a bit of a brain hangover the next day. Experts have long assumed that people’s heads would clear once they stopped taking the drug. That may not be the case. In a study published last night by the journal BMJ, a team of researchers from France and Canada linked benzodiazepine use to an increased risk of being diagnosed with Alzheimer’s disease. In the study, the greater a person’s cumulative dose of benzodiazepines, the higher his or her risk of Alzheimer’s. Taking a benzodiazepine for less than three months had no effect on Alzheimer’s risk. Taking the drug for three to six months raised the risk of developing Alzheimer’s by 32%, and taking it for more than six months boosted the risk by 84%. People taking a long-acting benzodiazepine were at greater risk than those on a short-acting one.

High blood pressure in midlife linked to later decline in memory, thinking skills

Beverly Merz
Beverly Merz, Executive Editor, Harvard Women's Health Watch

A new report in JAMA Neurology offers yet another reminder why keeping your blood pressure in the healthy range for as long as you can is a good life strategy. Researchers with the long-term Atherosclerosis Risk in Communities (ARIC) Neurocognitive Study found that memory and thinking skills declined significantly more over the course of a 20-year study in middle-aged people with high blood pressure than it did in those with healthy blood pressure. Interestingly, those who had normal blood pressure in midlife but who developed high blood pressure in their late 60s, 70s, and 80s didn’t have similar declines as those who developed high blood pressure earlier. The main take-home lesson from this study? The longer you live with normal blood pressure, the less likely you are to have memory and reasoning problems when you’re older.

Regular exercise changes the brain to improve memory, thinking skills

Heidi Godman
Heidi Godman, Executive Editor, Harvard Health Letter

There are plenty of good reasons to be physically active. Big ones include reducing the odds of developing heart disease, stroke, and diabetes. Maybe you want to lose weight, lower your blood pressure, prevent depression, or just look better. Here’s another one, which especially applies to anyone experiencing the brain fog that comes with age: exercise changes the brain in ways that protect memory and thinking skills. In a study done at the University of British Columbia, researchers found that regular aerobic exercise, the kind that gets your heart and your sweat glands pumping, appears to boost the size of the hippocampus, the brain area involved in verbal memory and learning.

Expert panel says “no” to widespread testing for Alzheimer’s, dementia

Stephanie Watson

A new report from the Alzheimer’s Association says that as many as 5 million Americans have Alzheimer’s disease or some other form of dementia. Every 67 seconds someone in the United States develops Alzheimer’s disease or dementia. That’s 470,000 Americans this year alone. Given that these thieves of memory and personality are so common and so feared, should all older Americans be tested for them? In proposed guidelines released yesterday, the U.S. Preventive Services Task Force said “no.” Why not? Even after conducting a thorough review of the evidence, the panel said that there isn’t enough solid evidence to recommend screening, especially since not enough is known about the benefits and the harms. In part, the recommendation is based on the sad fact that so far there aren’t any truly effective approaches to stop the forward progress of dementia.

PET scans peer into the heart of dementia

Daniel Pendick
Daniel Pendick, Former Executive Editor, Harvard Men's Health Watch

What’s bad for the heart is often bad for the brain. High cholesterol, high blood pressure, diabetes, and unhealthy “hardening” of the arteries increase the risk of mental decline or dementia later in life. A study published online today in Neurology shows that older people with the stiffest arteries are more likely to show the kinds of damage to brain tissue often seen in people with dementia. The study adds support to the “two hit” theory of dementia. It suggests that the accumulation of Alzheimer’s-linked amyloid protein in the brain may not pose problems until damage to small blood vessels that nourish the brain nudges them over into dementia. There may be a silver lining to this line of research: Efforts to improve cardiovascular health can also protect the brain.

Above-normal blood sugar linked to dementia

Heidi Godman
Heidi Godman, Executive Editor, Harvard Health Letter

There are many reasons to keep your blood sugar under control: protecting your arteries and nerves are two of them. Here’s another biggie: preventing dementia, the loss of memory and thinking skills that afflicts millions of older Americans. A study published today in the New England Journal of Medicine shows that even in people without diabetes, above normal blood sugar is associated with an increased risk of developing dementia. The study does not prove that high blood sugar causes dementia, only that there is an association between the two. For that reason, don’t start trying to lower your blood sugar simply to preserve your thinking skills, cautions Dr. Nathan. There’s no evidence that strategy will work, although he says it should be studied. But it is still worth keeping an eye on your blood sugar. Excess blood sugar can lead to diabetes and a variety of other health problems, including heart, eye, kidney, and nerve disease.