Alzheimer's disease is associated with decreased levels of the neurotransmitter acetylcholine in the brain. A key ingredient of acetylcholine is the amino acid choline. But for reasons that remain unclear, choline supplementation has little effect on Alzheimer's progression.

Ginkgo biloba, a living relic of the dinosaur age, is the oldest surviving species of tree on Earth. Poetically, it helps the oldest surviving people. An extract of ginkgo leaves helps prevent and treat many conditions associated with aging: stroke, heart disease, impotence, deafness, blindness, and memory loss. Recent studies show it also helps treat Alzheimer's disease.

People need oxygen to live, but oxygen also has a downside. In the body, some oxygen molecules become so highly chemically reactive that they disrupt other body processes. These troublemaker molecules are called free radicals, and many scientists believe that the damage they inflict (oxidative damage) is at the root of both cancer and heart disease. (Smoking and a high-fat diet greatly increase the number of free radicals in the blood.)