[A friend sent this to me and I found it to be enlightening. I have no idea where this info originally came from, so discuss these with your own doctor to be certain that the info is accurate.]
Can a healthy lifestyle prevent dementia and Alzheimer's disease? Observational studies have suggested it might, but unfortunately, the overall evidence isn't conclusive. What is known for sure is that healthy habits benefit all your body's organs, especially the heart and brain, and may therefore indirectly help ward off cognitive decline.
Factor #1: Don't smoke.
If you don't already have enough reasons to quit smoking, think about this: a long-term study reported in the Archives of Internal Medicine confirms that smoking is indeed a risk factor for dementia. In fact, heavy smoking in midlife was found to more than double the odds of developing Alzheimer's disease, dementia and vascular dementia.
Researchers in Finland surveyed 21,123 men and women starting in midlife and followed them for an average of 23 years. Of 5,367 study participants diagnosed with dementia later in life, 2,367 were smokers and 261 were heavy smokers (who smoked more than two packs a day). Compared with nonsmokers, the heavy smokers increased their risk of developing Alzheimer's by more than 157 percent and had a 172 percent higher risk of developing vascular dementia. One possible mechanism is that smoking increases inflammation, which is known to play a role in Alzheimer's.
Factor #2: Follow a Mediterranean-style diet.
Like exercise, diet probably exerts a positive impact on the brain via its effect on cardiovascular health. Numerous studies have confirmed that the Mediterranean diet, in particular, boosts both heart and brain health. The Mediterranean the diet emphasizes whole grains, fruits and vegetables, fish, nuts and olive oil and other healthy fats, and includes little red meat.
A recent study in the American Journal of Clinical Nutrition evaluated the eating habits of 3,790 participants in the Chicago Healthy Aging project, an ongoing examination of cognitive health in adults over age 65. Those whose diets adhered most closely to the principles of the Mediterranean diet performed better on the assessment tests at three-year intervals than those whose diets did not, suggesting that certain foods may slow the rate of cognitive decline.
Factor #3: Consider a DHA supplement.
Supplements, including vitamin D, vitamin B12 and omega-3 fatty acids, have also been studied for their potential brain-fortifying effects, with mixed results. Of the three, docosahexaenoic acid (DHA), an omega-3 fatty acid found in fish oil, seems to hold the most promise.
While a study in the Journal of the American Medical Association found that fish-oil supplements do not slow the progression of Alzheimer's disease once it has begun, another placebo-controlled study published in Alzheimer's & Dementia found that 900 mg of DHA per day, taken for 24 weeks, helped improve memory and brain function in people over age 55 with mild cognitive impairment. This suggests that to help the brain, these supplements should ideally be started early, before mental decline progresses too much.