04/19/2026
Omega-3 DHA and Alzheimer’s disease
People with a gene mutation known as APOE4 (E4) are four times more likely to develop Alzheimer’s disease (AD). Doctors thought those with E4 would need larger doses of the omega-3 DHA—one of the most prevalent fatty acids in the brain—to have adequate levels in their brain matter.
In this six-month study, 33 men and women, 15 with E4, at least age 55, with a family history of AD, but without the disease themselves, took a placebo or 2,152 mg of DHA per day, which included 0.1 percent EPA. Both groups restricted other polyunsaturated fatty acids, and took B complex vitamins including 1 mg of vitamin B12, 100 mg of B6, and 800 mcg of folic acid per day. B-vitamins help the body process omega-3s.
Discussing the findings, doctors said, “E4 carriers, despite having the same dose, had less omega-3s in the brain.” E4 carriers also had one-third the increase of EPA in spinal fluid compared to non-E4 participants.
Reference: The Lancet; 2020, PIIS2352-3964(20)30258-9