更多的證據，多吃魚可以補腦

More Evidence That Fish Is Brain Food

Older adults in developing countries who eat fish regularly seem to have a lower risk of dementia, a new study suggests.

Researchers found that the odds of having dementia generally declined as fish consumption rose among nearly 15,000 older adults living in China, India, or one of five Latin American countries.

For each increase in participants' reported fish intake — from never, to some days of the week, to most or all days of the week — the prevalence of dementia dipped by 19 percent.

The findings, published in the American Journal of Clinical Nutrition, mirror evidence from some studies in developed nations.

The findings also suggest that the fish-dementia link does not simply reflect the benefits of a generally higher-quality diet. The study found that adults who got the most meat in their diets tended to have a somewhat higher prevalence of dementia than those who never ate meat.

The findings are based on a one-time survey and do not prove cause and effect, note the researchers, led by Dr. Emiliano Albanese of King's College London in the UK.

"More substantive evidence," they write, will come from the next phase of the research, which is following these older adults over time to see whether fish intake is related to the risk of developing dementia in the future.

If fish does protect the aging brain, researchers believe that the benefits probably come from the omega-3 fatty acids found most abundantly in oily fish such as salmon, mackerel, and albacore tuna.

Lab studies show that omega-3 fats have a number of properties that could help stave off dementia, including actions that protect nerve cells, limit inflammation, and help prevent the build-up of the amyloid proteins seen in the brains of Alzheimer's patients.

SOURCE: American Journal of Clinical Nutrition, August 2009

Copyright Reuters

Editor's Note:

• 4 Fish Should Never Be Eaten — a Government Agency Agrees