Seafood consumption and Alzheimer’s disease
An NIEHS grantee and colleagues report that people with a higher risk of developing Alzheimer’s disease, who also consumed more seafood, showed fewer brain changes tied to the disease, despite exhibiting higher levels of mercury in their brains. The protective effects of eating seafood were only observed among people with the apolipoprotein 4 (APOE4) allele, a gene variant linked with increased risk of Alzheimer’s disease.
Mercury is a known neurotoxin, so the researchers wanted to determine whether seafood consumption raised brain mercury levels in older adults, and also whether seafood consumption or brain mercury levels correlated with brain changes related to Alzheimer’s. They examined deceased participants in the Memory and Aging Project who had reported seafood consumption annually, prior to their death.
Among 286 autopsied brains, the researchers found that higher levels of mercury were linked with eating more meals containing seafood each week. After adjusting for age, sex, education, and total energy intake, eating seafood one or more times a week was significantly correlated with fewer brain changes related to Alzheimer’s, including amyloid plaques and neurofibrillary tangles, but only among APOE4 carriers. The researchers also examined fish oil supplementation, but did not find the same protective effect among the small group of participants using these supplements.
Citation: Morris MC, Brockman J, Schneider JA, Wang Y, Bennett DA, Tangney CC, van de Rest O 2016. Association of seafood consumption, brain mercury level, and APOE epsilon4 status with brain neuropathology in older adults. JAMA 315(5):489-497.