In one study, 133 people over age 70 with mild cognitive impairment took a daily high-dose B-vitamin supplement containing 800 mcg of folic acid, 500 mcg of B12 and 20 mg of B6 or a placebo.
After two years, compared to placebo, homocysteine levels had decreased 30 percent, and executive mental function was stabilized. Those who started the study with the highest homocysteine levels benefited most.
In one study, 410 people with mild to moderate dementia took 240 mg of ginkgo biloba extract per day or a placebo.
After 24 weeks, while there was no change for placebo, the ginkgo group improved greatly in symptoms of apathy and indifference, sleep and nighttime behavior, sudden shifts in emotion, abnormal body movements, and overall mood.
Those with mild cognitive impairment who become depressed are more likely to develop dementia, and doctors said omega-3s may alleviate both cognitive decline and depression.
In one study, 50 people over age 65 with mild cognitive impairment and depressive symptoms took a supplement containing mostly DHA with EPA, EPA with DHA, or an omega-6 linoleic acid placebo.
After six months, compared to placebo, depressive symptoms improved in both omega-3 groups. In addition, the DHA with EPA group also had better verbal fluency and better self-reported physical health. The DHA with EPA supplement contained 1,550 mg DHA plus 400 mg EPA.