When older adults with memory problems eat more omega-3 fats from fish or supplements, their bodies show less of a type of cell damage linked to aging and brain decline.

Elderly people with memory problems who eat more fish oil-like fats (DHA and EPA) tend to have less damage from harmful molecules in their blood, which might help protect their brains.

Older adults with memory issues have more harmful oxidative damage in their blood compared to healthy older adults, which may be linked to their cognitive problems.

Taking omega-3 supplements every day for six months doesn’t seem to help people with mild to moderate Alzheimer’s think better, no matter what their blood homocysteine levels were to begin with.

When older male rats eat more DHA—a healthy fat found in fish—their brains produce less of a protein that normally trims brain connections too much as they age, which might help them keep their memory and thinking skills longer.

For people with early-stage Alzheimer’s, taking a specific fish oil supplement for 6 months might help them think a little better and function more normally—but only if their blood has low levels of a chemical called homocysteine before they start.