Alzheimer's Disease Archive

In the journals

Previous research has linked excess body fat with a higher risk of cognitive decline. In the past, most studies have gauged body fat based on body mass index (BMI). However, waist size may be a better way to predict possible cognitive impairment among older adults, according to a study in the Sept. 14, 2018, issue of the British Journal of Nutrition.

Researchers examined health data on 5,186 people ages 60 and older. They found that a larger waist size was associated with reduced performance in such mental abilities as attention and visuospatial skills (the ability to perceive the differences and similarities between objects). The study participants also scored lower on memory tests.

Ask the doctor

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Q. I know that some viruses live permanently inside us, but only make trouble now and then. I even heard recently that they might be a cause of Alzheimer's disease. Why do they sometimes cause disease, and can we keep that from happening?

A. We live all of our lives with various microorganisms on us and inside us. One example is the herpes family of viruses. Out of more than a hundred herpesviruses, there are nine that infect humans. Once we get infected with these viruses — usually early in life — they remain with us, "asleep" inside some of our cells. But periodically, they "wake up" (reactivate), start producing multiple copies of themselves, and infect other cells. That's what's happening when a cold sore suddenly forms on your lip.

Research we're watching

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Aggressively treating high blood pressure might help ward off cognitive changes, according to findings presented at the Alzheimer's Association International Conference in July. Researchers from the Systolic Blood Pressure Intervention Trial compared two strategies to manage high blood pressure in more than 9,300 older adults (average age about 68). One strategy aims to achieve the standard treatment level for high systolic blood pressure (the first number in a blood pressure reading), keeping it under 140 mm Hg. The more aggressive strategy sets a goal of less than 120 mm Hg. The aggressive strategy reduced not only heart risks, but seemed to protect the brain.

People in the more aggressively controlled blood pressure group were 19% less likely than those in the standard treatment group to develop new cases of mild cognitive impairment (often a forerunner to dementia). They were also 15% less likely to develop any form of dementia or mild cognitive impairment. This study provides another reason to work with your doctor to reduce high blood pressure.

Subjective cognitive decline often appears before memory loss and other symptoms.

Recent research suggests that the brain changes leading to Alzheimer's disease begin many years before the onset of symptoms.

Most often the disease is not diagnosed until it exists in full force, so finding earlier changes in thinking or behavior may help scientists better understand this process.

Research we're watching

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A new study published online June 21 by the journal Neuron links two common viruses to Alzheimer's disease. Based on data from three brain banks, researchers found that the brains of people with Alzheimer's disease had up to twice the levels of two viruses — herpesviruses 6A and 7 — compared with the brains of people who did not have dementia. The virus genes also appeared to have interacted with the human DNA in cells in the brain in ways that might have affected Alzheimer's disease risk.

Infection with these herpesviruses is very common. Up to 90% of people may be exposed to these viruses in childhood. They cause, among other things, a mild infection known as roseola, which produces a rash and a fever.

You're probably already doing a lot to ensure that you stay in good health and are able to enjoy your later years: eating right, exercising, getting checkups and screenings as recommended by your doctor. But it also makes sense to have some contingency plans for the bumps in the road that might occur.

1. Adapt your home. Stairs, baths, and kitchens can present hazards for older people. Even if you don't need to make changes now, do an annual safety review so you can make necessary updates if your needs change.
2. Prevent falls. Falls are a big deal for older people — they often result in fractures that can lead to disability, further health problems, or even death. Safety precautions are important, but so are exercises that can improve balance and strength.
3. Consider your housing options. You might consider investigating naturally occurring retirement communities (NORCs). These neighborhoods and housing complexes aren't developed specifically to serve seniors — and, in fact, tend to host a mix of ages — but because they have plenty of coordinated care and support available, they are senior-friendly.
4. Think ahead about how to get the help you may need. Meal preparation, transportation, home repair, housecleaning, and help with financial tasks such as paying bills might be hired out if you can afford it, or shared among friends and family. Elder services offered in your community might be another option.
5. Plan for emergencies. Who would you call in an emergency? Is there someone who can check in on you regularly? What would you do if you fell and couldn't reach the phone? Keep emergency numbers near each phone or on speed dial. Carry a cellphone (preferably with large buttons and a bright screen), or consider investing in some type of personal alarm system.
6. Write advance care directives. Advance care directives, such as a living will, durable power of attorney for health care, and health care proxy, allow you to explain the type of medical care you want if you're too sick, confused, or injured to voice your wishes. Every adult should have these documents.

To learn more ways to enjoy independence and good health in your senior years, buy Living Better, Living Longer, a Special Health Report from Harvard Medical School.

Here are some common warning signs of Alzheimer's disease. If you or someone you love is experiencing one or more of the following symptoms, talk to a doctor.

Trouble remembering things. At first, only short-term memory may be affected. The individual may forget an appointment or the name of a new acquaintance. She may also forget where she left things, or she may leave things in odd places (for example, putting her shoes in the microwave). Eventually, long-term memory is impaired, and the individual may not recognize family members.

News briefs

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An observational study published online May 30, 2018, by JAMA Psychiatry found that engaging in intellectually stimulating activities, even later in life, may lower the odds of dementia. Researchers followed over 15,000 Chinese men and women in their 70s for seven years with annual assessments of health and lifestyle habits, including a variety of leisure activities. The odds of being diagnosed with dementia during the study period were 29% lower in people who challenged their brains daily with such activities as playing board games, reading, and even betting on horse racing. In contrast, less mentally demanding recreational activities (like watching TV or shopping) or social activities (like going to tea with friends) did not appear to be associated with a lower risk of dementia. Other studies have found similar evidence, but this one made a special effort to adjust for factors like better overall health that might otherwise account for the association between brain exercise and dementia.

In the journals

Anticholinergic medications used to treat bladder conditions, Parkinson's disease, and depression are associated with an increased risk of dementia, according to a large study published online April 25, 2018, by The BMJ. Anticholinergic drugs help to contract and relax muscles. They work by blocking acetylcholine, a substance that also transmits messages in the nervous system. In the study, researchers compared the medical records of 40,770 people older than 65 who were diagnosed with dementia and 283,933 seniors without.

They found that people diagnosed with dementia were up to 30% more likely to have been prescribed anticholinergic medications for Parkinson's, bladder problems, or depression. Frequently prescribed anticholinergic drugs include procyclidine (Kemadrin) for Parkinson's; tolterodine, oxybutynin, and solifenacin (Vesicare) for urological conditions like overactive bladder or incontinence; and amitriptyline, dosulepin, and paroxetine for depression. However, there was no association between dementia and anticholinergic drugs used to treat other common conditions like hay fever, travel sickness, and stomach cramps.

Research we're watching

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High cardiovascular fitness during middle age may lower the likelihood of dementia late in life, according to a decades-long study.

For the study, researchers asked 191 middle-aged women to ride an exercise bike until they were exhausted. They then grouped the women according to their peak cardiovascular capacity. Just 40 women met the criteria for high fitness, while 92 were in the medium category, and 59 were in the low category.