A 64-year-old woman comes to the office for a health maintenance visit. Her medical issues include hypothyroidism treated with levothyroxine and postmenopausal vaginal dryness treated with estrogen cream. The patient exercises 3 times a week and eats a well-balanced diet. She does not use tobacco and drinks a glass of wine 3-5 days a week. She works as a volunteer at her local public library. The patient's 88-year-old father has Alzheimer disease and was recently placed in a nursing facility. She mentions that it has been difficult to see her father decline and was upset when he failed to recognize her at her last visit. She says, "I do crossword puzzles every day because I am afraid I will develop Alzheimer disease" and mentions that she has seen information on the internet and television describing beneficial effects from ginkgo biloba, fish oil, and vitamins. The patient asks, "Will any of these supplements help prevent dementia?" Which of the following is the most appropriate advice for this patient?
Alzheimer disease (AD) is increasingly prevalent with advancing age, and the older population is frequently targeted with advertisements for products with unproven efficacy. In particular, asymptomatic individuals with a family history of AD often have concerns about developing dementia and may ask for advice regarding which dietary supplements and vitamins to take. Although many observational studies have reported associations with various supplements and cognitive health, there is insufficient evidence to conclude that any dietary or vitamin supplements reduce the risk of dementia.
In counseling this patient, general lifestyle recommendations that have other health benefits (eg, physical exercise, social interaction, cognitive stimulation) can be made, although there is no definitive evidence that these specifically prevent dementia. For adults with a balanced diet, there is no convincing evidence that taking multivitamins is either helpful or harmful.
(Choice A) There is no clear evidence to date that supplementation with vitamin B12 and/or folate prevents dementia or slows cognitive decline.
(Choice B) Ginkgo biloba has not demonstrated efficacy in reducing the incidence of AD and is not routinely recommended. If patients wish to take it, a quality brand with demonstrated purity should be used.
(Choice C) Omega-3 fatty acids can help decrease cardiovascular risk factors for dementia and may reduce the risk of death from coronary heart disease. However, randomized trials have not demonstrated a direct impact on preventing dementia.
(Choice E) Randomized trials of antioxidants (eg, vitamin E, vitamin C, beta-Carotene, selenium) conducted in older individuals with normal cognition or mild cognitive impairment have failed to demonstrate reduction in incident dementia. Vitamin E may have a modest benefit in slowing disease progression in patients with mild to moderate AD.
Educational objective:
To date, there is no conclusive evidence that any vitamins or dietary supplements are effective in preventing dementia. Vitamin E is not recommended for the prevention of Alzheimer disease in healthy adults, but it has shown modest benefit in patients with mild to moderate forms of the illness.