"THE ANTI-ALZHEIMER'S PRESCRIPTION: The Science-Proven Plan to Start at Any Age," by Vincent Fortanasce, Gotham, $26 (nf)

You've probably heard the bad news about Alzheimer's, and maybe even remember what it was: the disease strikes half of all people who are 85 or older.

But Alzheimer's and other dementias are not inevitable, says neurologist Dr. Vincent Fortanasce. In his new book, "The Anti-Alzheimer's Prescription," the clinical professor at the University of Southern California makes the case that by choosing the right food, exercising our bodies and brains, and learning to reduce stress, we can prevent these memory-robbing diseases.

Even patients who are genetically predisposed to get Alzheimer's, he says, can delay its occurrence for 10 or 15 years.

His prescription, however, isn't for the lazy or gluttonous.

It's tempting to gloss over the many pages of physiology and chemistry in this book, and skip instead to the lists of super foods and exercises. But Fortanasce, who is also a psychiatrist and bioethicist, argues that we're more likely to follow his prescription if we understand the science behind it. So he spends a fair amount of time discussing the ins and outs of anabolic and catabolic hormones, insulin-deleting enzymes and the like.

Obesity and related insulin resistance, as well as inflammation — as indicated by pro-inflammatory markers such as high concentrations of C-reactive protein and homocysteine — are now believed to increase the risk of Alzheimer's disease, he writes.

Obesity increases the risk by 300 percent for women, and 30 percent to 50 percent for men, he says. Diabetes increases the risk by at least 50 percent.

So Fortanasce's "anti-Alzheimer's diet" eschews refined foods and simple carbohydrates, and is big on foods that have a low "glycemic index."

His "golden dozen" foods include berries (eat at least three-quarters of a cup a day, he advises), apples, greens, yogurt and cruciferous vegetables such as broccoli.

Exercise, he reminds us, regulates hormones such as thyroid, estrogen and insulin-like growth factors that affect insulin, stimulate the immune system and decrease inflammation.

And don't forget to exercise your brain, he says, with puzzles, foreign languages and memorization. The trick, he says, is to engage in activities your brain isn't already used to (if you're a Sudoku fanatic, try something else for a change).

But don't stress out over any of this. Stress, Fortanasce says, is a "sentinel risk factor" for Alzheimer's.

e-mail: jarvik@desnews.com