Researchers have explored many complementary health approaches for preventing or slowing dementia, including Alzheimer’s disease. Currently, there is no strong evidence that any complementary health approach or diet can prevent cognitive impairment.

What is Alzheimer's disease? (For further reading)

What the Science Says

Following are some of the complementary health approaches that have been studied in recent years.

• Fish Oil/Omega-3s. Among the nutritional and dietary factors studied to prevent cognitive decline in older adults, the most consistent positive research findings are for omega-3 fatty acids, often measured as how much fish people ate. However, taking omega-3 supplements did not have any beneficial effects on the cognitive functioning of older people without dementia.
• Ginkgo. An NCCIH-funded study of the well-characterized ginkgo supplement EGb-761 found that it didn’t lower the incidence of dementia, including Alzheimer's disease, in older adults. Further analysis of the same data showed that ginkgo did not slow cognitive decline, lower blood pressure, or reduce the incidence of hypertension. In this clinical trial, known as the Ginkgo Evaluation of Memory study, researchers recruited more than 3,000 volunteers age 75 and older who took 240 mg of ginkgo daily. Participants were followed for an average of approximately 6 years.
• B-vitamins. Results of short-term studies suggest that B-vitamin supplements do not help cognitive functioning in adults age 50 or older with or without dementia. The vitamins studied were B12, B6, and folic acid, taken alone or in combination.
• Curcumin, which comes from turmeric, has anti-inflammatory and antioxidant properties that might affect chemical processes in the brain associated with Alzheimer’s disease, laboratory studies have suggested. However, the few clinical trials (studies done in people) that have looked at the effects of curcumin on Alzheimer’s disease have not found a benefit.
• Melatonin. People with dementia can become agitated and have trouble sleeping. Supplements of melatonin, which is a naturally occurring hormone that helps regulate sleep, are being studied to see if they improve sleep in some people with dementia. However, in one study researchers noted that melatonin supplements may worsen mood in people with dementia.
• For caregivers, taking a mindfulness meditation class or a caregiver education class reduced stress more than just getting time off from providing care, a small, 2010 NCCIH-funded study showed.

Side Effects and Risks

• Don’t use complementary approaches as a reason to postpone seeing a health care provider about memory loss. Treatable conditions, such as depression, bad reactions to medications, or thyroid, liver, or kidney problems, can cause memory impairment.

• Keep in mind that although many dietary supplements (and some prescription drugs) come from natural sources, “natural” does not always mean “safe.”
• Some dietary supplements have been found to interact with medications, whether prescription or over-the-counter. For example, the herbal supplement  St. John’s wort interacts with many medications, making them less effective. Your health care provider can advise you.