Nonconventional Treatments of Dementia/Mild Cognitive Impairment

If current population trends continue and treatments that arrest or reverse Alzheimer disease (AD) are not found, the number of patients with AD in the United States is projected to increase to more than 13 million by the year 2050.1 Numbers of persons afflicted with severe cognitive impairment caused by traumatic brain injury and stroke also continue to increase. Developing effective and cost-effective treatment approaches for AD and the other dementias is clearly an urgent priority. In addition to conventional pharmacologic treatments of dementia and milder forms of cognitive impairment, promising research findings are being reported for many nonconventional treatments. “Nonconventional” treatments are those biologic, somatic, mind-body, and energy-information approaches not currently accepted in Western biomedical psychiatry. This column provides a brief overview of the evidence for selected nonconventional approaches used to treat dementia and mild cognitive impairment in the United States and other Western countries. A review of more substantiated approaches in this issue will be followed in the next installment by highlights of approaches for which there is limited evidence at present. DIETARY MODIFICATION Epidemiologic studies, case control studies, and prospective trials suggest that persons who consume a high-fat, high-calorie diet are at significantly greater risk for AD than are persons who have moderate fat intake and restrict total calories. A meta-analysis of findings from 18 community-wide studies concluded that the risk of AD increased linearly at a rate of 0.3% with every 100-calorie increase in daily intake.2 However, a systematic review of 6 case control studies and 3 cohort studies that examined dietary preferences in dementia concluded that there is no compelling evidence for causal relationships between specific dietary factors and the risk of becoming demented.3 Consistent relationships between dietary protein, vitamins, and minerals and the risk of dementia were not identified. Evidence from epidemiologic studies suggests that regular intake of foods rich in omega-3 fatty acids may be inversely related to cognitive impairment or the rate of overall cognitive decline in nondemented elderly persons. However, findings to date are inconclusive. A large epidemiologic study concluded that consuming fish 2 to 3 times weekly significantly reduces the risk of cognitive decline in elderly populations.4 Cognitive impairment scores were analyzed for 2 groups of elderly men (aged 69 to 89) with different dietary preferences. High fish consumption was inversely correlated with cognitive impairment. Findings from a prospective cohort study suggest that persons who consume fish at least weekly have a 60% lower risk of AD than do persons who seldom eat fish.5 However, another study failed to show a correlation between fish consumption and the risk of AD.6 Moderate but not heavy consumption of wine (2 to 4 glasses per day) is also associated with a reduced risk of AD.7 In a large 2-year follow-up study, moderate alcohol consumption was found to be associated with a significant reduction in risk for both AD and vascular dementia.8 MEDICINAL HERBS AND SUPPLEMENTS Ginkgo Biloba Standardized preparations of Ginkgo biloba are widely used in Europe to treat dementia and other neurodegenerative diseases. More recently, use of G biloba has become widespread in North America. Systematic reviews and early meta-analyses of double-blind controlled studies show that standardized preparations of G biloba in dosages between 120 and 600 mg/d taken for several weeks to 1 year result in consistent modest improvements. These improvements involve memory, general cognitive functioning, and activities of daily living in mild to moderate cases of both AD and multi-infarct dementia and are equivalent to improvements seen with donepezil (Aricept), a