In the fight against memory loss, nothing is certain, doctors say.
A seemingly steady stream of new research purposts to show supplements' and vitamins' promise in preventing or slowing cognitive decline, but in reality, no hard evidence supports taking any of them. At the same time, such supplements have been proved safe, barring drug interactions and other complications, so some doctors recommend trying them anyway.
With millions of aging Americans experiencing a decrease in cognitive function, the need for a natural prevention method is obvious.
As many as 2.4 million to 4.5 million Americans have Alzheimer's disease, according to the National Institute on Aging. Between 1 and 4 percent of people over the age of 65 have vacular dementia, according to the Mayo Clinic.
At the forefront of the supplement claims to improve brain function has been fish oil. Several observational studies - which did not involve the scientific vigor of control groups - have found benefits in cognition, or a lower rish of dementia, among older people who ate a lot of fish, although results overall have been mixed.
A study from Britain, to be published in the June issue of the American Journal of Clinical Nutrition, has found no benefit in taking fish oil supplements in cognitively healthy older adults.