Eating a fish a week can make dementia meek, new study concludes

Eating seafood is linked to a reduced risk of dementia-associated brain changes in people who carry the ApoE4 gene variation, which increases the risk for Alzheimer’s disease. Eating seafood was not linked to similar changes in those who carried other forms of the ApoE gene.

The study, published in the Journal of the American Medical Association, looked at 286 autopsied brains and also found that eating seafood was linked to increased mercury in the brain, but that mercury levels were not linked to brain abnormalities.

After controlling for age, sex, education and other factors, the researchers found that compared with those who ate less seafood, ApoE4 carriers who had one seafood meal or more a week had lower densities of the amyloid plaques and neurofibrillary tangles typical of Alzheimer’s disease. They had a 47 percent lower likelihood of having a post-mortem diagnosis of Alzheimer’s.

Consumption of fish oil supplements was not correlated with pathological brain changes.

The lead author, Martha Clare Morris, a professor of epidemiology at Rush University, said that mercury from fish appears to pose little risk for aging people.

But, she said, there are studies that show mercury consumption in pregnancy can cause cognitive problems in babies.

“Most studies in dementia have found that one seafood meal a week is beneficial,” she said, though “they haven’t found that the more you eat, the lower the risk.”

Tylenol and asthma

Taking Tylenol (acetaminophen) during pregnancy is associated with a slight increase in the risk for asthma in offspring, a new study has found.

Norwegian researchers used health data on 95,200 pregnant mothers between 1999 and 2008, and followed 53,169 of their children after birth.

After controlling for various health and behavioral characteristics, they found that prenatal exposure to Tylenol was associated with a 13 percent increased risk for asthma at age 3. The more Tylenol the mother had taken during pregnancy, the higher the risk.

The study, in The International Journal of Epidemiology, was designed to minimize the possibility that the increased risk was caused by an illness rather than by the Tylenol itself.