A study published on 2 February 2016 in Volume 315, Issue 5 of the Journal of the American Medical Association has found eating seafood at least once a week could lower an individual’s chance of developing Alzheimer’s disease.
Conducted by researchers at Rush University Medical Center in Chicago, the study also found that although eating seafood increased mercury levels in the brain there was no connection found between higher mercury levels and Alzheimer’s disease.
Lead researcher Martha Clare Morris said her team came to its findings through analysing almost 300 deceased persons who had donated their bodies to science. The average age at death was 90 years and 67 percent were women. Seafood intake was first measured by a food frequency questionnaire at an average of 4.5 years before death. The researchers said the group were a largely non-Hispanic Caucasian cohort.
Numerous studies have found protective associations between seafood consumption and dementia. Little is known about the relationship between seafood consumption and brain neuropathology. Seafood is a source of mercury, a neurotoxin that impairs neurocognitive development. Mercury toxicity is reduced by selenium, an essential nutrient present in seafood.
Fish oil supplements were not found to not have the same effects as actually eating seafood.
“To our knowledge, this is the first study to report on the relationship between brain concentrations of mercury and brain neuropathology or diet,” said the authors.
“The finding of no deleterious correlations of mercury on the brain is supported by a number of case-control studies that found no difference between Alzheimer disease patients and controls in mercury concentrations in the brain, serum, or whole blood,” the authors stated.