Martha Clare Morris, Sc.D.
Rush University Medical Center
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 typically 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 Alzheimer’s-related brain changes. 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 in the brain 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 Alzheimer’s-related brain changes, 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 ε4 status with brain neuropathology in older adults. JAMA 315(5):489-497.