While scientists arent exactly ready to anoint an anti-Alzheim-ers diet, they are edging closer to an understanding of the complex inter-actions of nutrients that might help ward off Alzheimers disease. A newly published study of 2,148 senior New Yorkers has identified a dietary pattern that seems to represent an optimal combination of nutri-ents that may protect against Alzheimers, while minimizing elements associated with greater risk.Yian Gu, PhD, of Columbia University Medical Center, and colleagues explained, Epidemiological evidence linking diet, one of the most important modifiable envi-ronmental factors, and risk of Alzheimers disease is rapidly increasing. However, current literature regarding the impact of individual nutrients or food items on Alzheimers disease risk is inconsistent, partly because humans eat meals with complex combinations of nutrients or food items that are likely to be synergistic.So the researchers looked for possibly protective dietary patterns among 2,148 adults age 65 and older without dementia living in New York. Participants provided information about their diets and were assessed for the development of dementia every 18 months for an average of four years. Several dietary patterns were identified with varying levels of seven nutrients previously shown to be associated with greater Alzheimers disease risk-satu-rated fatty acids and omega-6 fatty acids-and with lesser risk: monounsaturated fatty acids, omega-3 fatty acids, vitamin E, vitamin B12 and folate.During the follow-up, 253 individuals developed Alzheimers disease. One dietary pattern was significantly associated with a reduced risk of the disease: high intakes of salad dressing, nuts, fish, tomatoes, poultry, fruits and cruciferous and dark and green leafy vegetables and low intakes of high-fat dairy, red meat, organ meat and butter.The dietary pattern resembles whats been called the Mediterranean-style diet. In 2006, Nikolaos Scarmeas, MD, of Co-lumbia University and colleagues published findings that a Mediterranean-style diet lowered Alzheimers risk among participants in the Washington Heights-Inwood Columbia Aging Project. Dr. Scarmeas was also an investigator in the new study.The combination of nutrients in the low-risk dietary pattern reflects multiple pathways in the development of Alzheim-ers disease, Gu and colleagues noted. For example, vitamin B12 and folate lower the bodys levels of homocysteine, an amino acid thought to play a role in dementia. Vitamin E might prevent Alzheimers dis-ease via its strong antioxidant effect, the researchers suggested, and fatty acids may be related to dementia and cognitive function through atherosclerosis, thrombo-sis or inflammation via an effect on brain development and membrane functioning or via accumulation of beta-amyloid (chief component of the plaques associ-ated with Alzheimers).Although the study wasnt designed to prove cause-and-effect, Gu said, We con-trolled for a variety of other lifestyle factors in our analysis, so the relationship between this dietary pattern and Alzheimers disease could be considered as independent of these controlled factors, including smoking status, BMI, etc.The researchers concluded, Our find-ings provide support for further exploration of food combination-based dietary behavior for the prevention of this important public health problem.TO LEARN MORE: Archives of Neurology, June 2010; abstract at dx.doi.org/10.1001/archneurol. 2010.84. Alzheimers Association www.alz.org
