Alzheimer's Disease Archive

Medications called anticholinergics are used to treat a host of conditions—overactive bladder, depression, allergies, and Parkinson's disease. They usually aren't recommended for older adults because one of the most common side effects is confusion and difficulty reasoning. Early studies have also indicated that long-term anticholinergic use is associated with an increased risk of dementia, and a recent study by researchers at the University of Washington adds more evidence to support that connection. The results were published online Jan. 26, 2015, by JAMA Internal Medicine.

The researchers tracked almost 3,500 men and women ages 65 and older who were free of dementia. When they matched prescription data for the previous 10 years with the participants' health outcomes, they determined that using anticholinergics was associated with an increased risk of developing dementia. Moreover, dementia risk increased with the dosage of the drugs and the length of time they were used. While people who had taken these drugs daily for the equivalent of three months had no increase in risk, those who had used them for over three years had a 54% greater risk than nonusers.

By Dr. Anne Fabiny, Editor in Chief, Harvard Women's Health Watch

If you have diabetes or prediabetes and you need motivation to get your blood sugar under control, consider this: a study published Dec. 2, 2014, in Annals of Internal Medicine suggests that diabetes in midlife appears to age the mind at a faster rate in later life. Researchers analyzed changes in the thinking skills of more than 15,000 people during a 20-year period. The average age at the start of the study was 57. Twenty years later, among people with a history of diabetes, there was 19% more decline than expected. There were even declines, although smaller, among people with a high blood sugar condition known as prediabetes. "We know that over time, diabetes, like hypertension, will cause mini-strokes in the brain that will impair one's thinking and memory. This study strengthens the claim that addressing cardiovascular risk factors like diabetes early may prevent dementia in the future," says Dr. David Hsu, a psychiatrist in the Center for Alzheimer Research and Treatment at Harvard-affiliated Brigham and Women's Hospital. You can lower your blood sugar—and your risk of diabetes—by exercising, losing weight, and cutting back on refined grains and added sugars. 

Sometimes dementia has multiple causes. Understanding the diagnosis helps with planning for medical care.

Alzheimer's disease is the most common cause of dementia in older adults—present in up to 80% of cases. As Alzheimer's progresses, abnormal proteins start to collect in the brain and affect memory, reasoning, planning, and other brain functions.

Q. I read somewhere that benzodiazepines cause Alzheimer's disease. I took Valium for a few weeks after my husband died. How does this change my risk of dementia?

A. In September, a team of researchers from France and Canada reported that in people over age 66, those who had been diagnosed with Alzheimer's disease were more likely to have used benzodiazepines—a category that includes Valium (diazepam) and similar drugs—during the preceding five years than were people who didn't have Alzheimer's. Using the drugs continuously for three to six months was associated with a 32% higher risk than using them for three months or less; using them for six months or more was associated with an 84% greater risk. People who took benzodiazepines for three months or less had no higher risk than those who had never taken them.

Long-term use of benzodiazepines, which help people fight anxiety or sleep better, appears to be linked to an increased risk of Alzheimer’s disease. 

If you notice troubling memory changes, it's probably not cause for immediate alarm, suggests a study published online Sept. 14, 2014, in Neurology. Researchers tracked more than 500 people with an average age of 73 and found there was about a decade from the time memory complaints began until there was a diagnosis of mild cognitive impairment, and 12 years before there was a diagnosis of dementia. But the delay in diagnosis doesn't mean memory issues in older adults should be ignored. It may signal the need for you to get a baseline assessment that can be used for comparison in the future.

How do you know what's normal and what isn't? "Unless memory problems are extreme and persistent, they are not considered indicators of memory-impairing illnesses. Some memory problems become more pronounced with age, but these difficulties often tend to be related to absentmindedness," says Harvard Medical School psychology instructor Dr. Kim Willment. "Struggling to remember a particular word or a name is not at all unusual. Walking into a room and not remembering the reason for going would also be quite common. We become more worried when we hear that a person has completely forgotten a major event or activity or pertinent details from that activity within several weeks. For example, it would be concerning to have attended a wedding two to three weeks ago and then forgotten the wedding itself or who got married," says Dr. Scott McGinnis, an instructor in neurology at Harvard Medical School.

Q. My sister was recently diagnosed with dementia with Lewy bodies. How does this differ from dementia because of Alzheimer's disease?

A. Alzheimer's disease is the most common cause of dementia in older people, but it is only one of many causes. Your sister's condition, dementia with Lewy bodies (DLB), is actually the second most common type of dementia. Lewy bodies are clumps of proteins found in the brain cells of people diagnosed with DLB, as well as in people with certain other degenerative neurologic conditions, like Parkinson's disease. Although the symptoms of Alzheimer's disease and dementia with Lewy bodies overlap substantially, there are some that are more typical of DLB.

Q. Some people claim that ginkgo biloba may improve memory. What's your take on this supplement?

A. I know you'd like a simple and unambiguous answer—and I wish I could give it to you. Here's how I size up the evidence. I reserve the right to change my mind as new evidence emerges. There is little evidence that ginkgo protects a person from developing the age-related memory impairment that bothers many people. There is even less evidence that it protects against developing the condition called mild cognitive impairment, or that ginkgo protects people with mild cognitive impairment from developing dementia. There are a few studies that find ginkgo may slightly slow the progression of dementia in people with Alzheimer's disease or vascular dementia (dementia caused by impaired blood supply to the brain). But other studies fail to find such a benefit. I haven't considered taking ginkgo to protect against memory loss: the evidence just isn't there, at least so far. 

You can add low vitamin D levels to the list of risk factors associated with dementia and Alzheimer's disease. A study published online in Neurology on Aug. 6, 2014, found that in people ages 65 and older, low levels of vitamin D in the blood were associated with a 53% increased risk for developing dementia, and about a 70% increased risk for developing Alzheimer's disease (AD), compared with normal blood levels of vitamin D. Blood levels of vitamin D that were extremely low were associated with even higher risks: 125% for developing dementia, and 120% for developing AD. The study didn't show that low and extremely low vitamin D levels cause dementia or Alzheimer's, and it didn't show that taking vitamin D pills or increasing the amount of vitamin D in the diet would prevent dementia and Alzheimer's. But could it help? "I would be very surprised if vitamin D supplementation alone would offer protection against dementia. AD is a process 15 to 20-plus years in the making, and most if not all of the mechanisms are probably in place five or six years before a dementia diagnosis," says neurologist Dr. Scott McGinnis, a Harvard Medical School instructor. Meantime, get your Recommended Dietary Allowance of vitamin D, which you need for strong bones, immune function, and cell growth.