How you can lower your risk for Alzheimer's

Hardly a day goes by that doesn't herald a new scheme for preventing Alzheimer's disease. And millions of baby boomers who witnessed a parent's struggle with dementia can't help but pay attention as they approach the age when their mother or father first displayed signs of disease.

Is there a way to cut through the hype and find out what measures, if any, will help stave off dementia?

To answer this question, I tracked down the doctor who diagnosed my mother 30 years ago.

My mom was 64 when she broke the news to me in her bedroom as her hands worried an afghan that she'd knitted years earlier. I was only 20 at the time, but I remember feeling a sense of my own vulnerability even then.

When my mother died five years later, following a rapid decline that left her unable to walk or speak, I began to detect what I was sure must be early signs of dementia in myself.

If I failed to locate a word or recall the name of a casual acquaintance, I'd be swamped with anxiety.

Eventually, to restore a sense of control over my mind and life, I decided to take a rational approach: I'd pack my worries away until I got closer to the age at which dementia struck my mother - by which time there would surely be a cure. I married, earned a doctorate, moved to Israel and back, embarked on a career in science, had two children. And then last year I turned 50.

Early or late onset

To understand my mother's disease and my own risk, I phoned Columbia University's Richard Mayeux.

In the late 1980s, Mayeux co-founded what is now Columbia's Taub Institute for Research on Alzheimer's disease and the Aging Brain. Although he has yet to find a cure, Mayeux has discovered a great deal about how Alzheimer's is passed on from one generation to the next.

Alzheimer's disease has traditionally been classified as early-onset or late-onset, depending on whether a patient is diagnosed before or after age 65.

But, according to Mayeux, the decision to separate Alzheimer's patients into two groups was made for the convenience of researchers.

"At one point we thought that the early-onset form was more likely to be genetic than the late-onset form. But I don't think anybody buys that right now," he said.

(A third, familial form of Alzheimer's is extremely rare, but it is associated with onset in the 50s or younger, and children of these people have a 50 percent risk of carrying the disease gene. Based on my mother's family history, it was unlikely that she carried a familial Alzheimer's mutation.)

After everything I'd read about early- and late-onset disease, Mayeux's dismissal of the age-65 distinction came as a surprise. If the genetics of early-onset and late-onset Alzheimer's are similar, then my mother's illness might not have been determined by genetic factors alone, but, as with late-onset disease, was probably due to some combination of genes and environmental factors.

In that case, might I be able to reduce my risk?

Staying active

"It's not diet, and there's no medication," Mayeux said. "But regular physical activity really is preventive. It even helps people who have early-stage disease. Being mentally active also is good. These are from randomized studies. It's been proven from animal studies all the way up through humans."

Just this summer, three studies presented at the Alzheimer's Association International Conference reported beneficial effects when people with mild cognitive impairment or Alzheimer's engaged in aerobic exercise at least three times a week.

Mayeux's emphasis on regular exercise mirrors a growing consensus in the medical community that what's good for the heart is good for the brain.

Recently, a heart-healthy diet with an emphasis on leafy greens and berries was shown to correlate with a reduced risk of Alzheimer's disease. But, Mayeux doesn't include diet in his list of proven interventions because, by the rigorous standards required to prove that Intervention A protects against Disease B, science has yet to demonstrate that changing one's diet can alter one's risk of Alzheimer's.

Smoking, caffeine

I couldn't argue with the apparent value of physical and mental exercise, but I had to ask: What ever happened to smoking? A handful of studies claimed that smokers have a reduced rate of Alzheimer's disease, but none have done so in recent years.

"It has gone back and forth. At one point people thought that if you smoked, you wouldn't get Alzheimer's. Now, more of us think that's probably not true."

What about coffee?

Mayeux said that the caffeine studies in animals look promising. Although dozens of studies have reported on the link between caffeine intake and protection from dementia in humans - and many have found a correlation - there has been no large randomized controlled trial that could prove cause and effect.

Increasing healthy habits

None of this was definitive, but it helped me come up with a plan: I'd double my aerobic exercise frequency to four days a week, continue to seek mentally challenging work as a science writer and punctuate my mornings with a couple of coffee breaks. And because I am willing to accept a lower standard of proof on the diet front, I decided to increase my intake of leafy greens and berries.

Should I be tested?

One thing still nagged me: whether I could determine my own risk of developing the disease.

Mayeux believes that most of the genes that contribute to Alzheimer's have been identified, about 30 in all. Theoretically, someone could sequence my DNA, look at those genes and estimate my risk. So should I be tested?

Mayeux thinks not.

"You only screen somebody (or a disease) if you have a means of intervening" to mitigate it, he said. Genetic screening would be most helpful if it could identify a specific target for treatment.

He gives the example of cholesterol. Although many people with high cholesterol will not have heart attacks, high cholesterol is a "modifiable risk factor." That means a person can reduce her cholesterol level through a combination of diet and medication and thereby reduce her risk of heart attack.

"That's what we're trying to do," he said, but "we just haven't found a good biomarker like cholesterol, the cholesterol equivalent for Alzheimer's disease."

Targeted therapies

In 2005, a New Yorker article describing Mayeux's research imagined that "a decade from now, your doctor will look up your gene profile and decide whether you have a high risk for Alzheimer's, and then give you a prophylactic treatment of some sort."

Is the development of targeted therapies still his goal?

"Oh, I think it's actually everybody's dream," he says. But it requires figuring out which combinations of genetic mutations lead to increased risks and then designing treatments that will reduce these risks.

The task seems monumental, but Mayeux remains optimistic: "They're doing some very creative things with genes, so you never know, you never know."

Mental checkups

For baby boomers and relatives of Alzheimer's patients who are anxious about their own health, Mayeux conducts a baseline evaluation of their mental function that includes solving a simple math problem, remembering a story or a few words, naming the last five presidents, writing a complete sentence and drawing boxes or cubes.

He said they return for yearly follow-ups "until they are convinced they are not progressing, and then they send me a postcard saying, 'I'm still good, doc.' "

Annual testing might be a good strategy for keeping my own Alzheimer's worries at bay - at least for as long as the results remain negative.

In the near term, though, once I finish this cup of coffee, I'll get on my bike and do what's good for the heart. I'll do the same thing the next day, a day or two after that and so on for as long as possible to stay healthy.

And I hope that my brain will follow.

10 warning signs of Alzheimer's

What is a possible symptom of dementia and what is normal "getting older" behavior? The Alzheimer's Association gives these 10 early warning signs of Alzheimer's disease and compares them to typical age-related changes:

<span class="fact box text bold">1. Early memory loss that disrupts daily life.</span> Forgetting recently learned information; forgetting important dates or events; asking for the same information over and over.

<span class="fact box text bold">Normal age change:</span> Sometimes forgetting names or appointments, but remembering them later.

<span class="fact box text bold">2. Challenges in planning or solving problems.</span> Having trouble following a familiar recipe or keeping track of monthly bills.

<span class="fact box text bold">Normal age change:</span> Making occasional errors when balancing a checkbook.

<span class="fact box text bold">3. Difficulty completing familiar tasks.</span> Trouble driving to a familiar location, managing a budget at work or remembering the rules of a favorite game.

<span class="fact box text bold">Normal age change:</span> Occasionally needing help to use the settings on a microwave or to record a television show.

<span class="fact box text bold">4. Confusion with time or place.</span> Forgetting where you are or how you got there. <span class="fact box text bold">Normal age change: </span>Getting confused about the day of the week but figuring it out later.

<span class="fact box text bold">5. Trouble with visual images and spatial relationships. </span>Difficulty reading, judging distance and determining color or contrast

<span class="fact box text bold">Normal age change: </span>Vision changes related to cataracts.

<span class="fact box text bold">6. Problems speaking or writing.</span> Stopping in the middle of a conversation and having no idea how to continue; repeating yourself.

<span class="fact box text bold">Normal age change: </span>Sometimes having trouble finding the right word.

<span class="fact box text bold">7. Misplacing things. </span>Putting things in unusual places; losing items and being unable to go back over your steps to find them again; accusing others of stealing.

<span class="fact box text bold">Normal age change:</span> Misplacing things from time to time and retracing steps to find them.

<span class="fact box text bold">8. Poor judgment. </span>Giving large amounts to telemarketers or paying less attention to grooming.

<span class="fact box text bold">Normal age change:</span> Making a bad decision once in a while.

<span class="fact box text bold">9. Withdrawal from work or social activities. </span>Removing yourself from hobbies, social activities, work projects or sports.

<span class="fact box text bold">Normal age change: </span>Sometimes feeling weary of work, family and social obligations.

<span class="fact box text bold">10. Changes in mood and personality.</span> Becoming confused, suspicious, depressed, fearful or anxious.

<span class="fact box text bold">Normal age change:</span> Developing very specific ways of doing things and becoming irritable when a routine is disrupted.

Source: Alzheimer's Association