Dietary Patterns and Alzheimer's Disease Risk

JAMA's Archives of Neurology published an article last week that looked at dietary patterns in older adults and the incidence of Alzheimer's Disease - "Food Combination and Alzheimer Disease Risk: A Protective Diet."

Reference:

Gu, Y. Nieves, J.W., Stern, Y. Luchsinger, J.A. & Scarmeas, N. (2010). Food Combination and Alzheimer Disease Risk: A Protective Diet. Archives of Neurology.;67(6):699-706. Published online April 12, 2010 (doi:10.1001/archneurol.2010.84).

This was a large group, long-term study, which marks it as useful for looking at which facotrs in the diet might help prevent AD. This is the key finding:

In this prospective study, we identified a DP that explained variation of AD-related nutrients and was strongly protective against the development of AD, even after controlling for multiple covariates. This DP reflected a diet rich in -3 PUFA, -6 PUFA, vitamin E, and folate, but with lower SFA and vitamin B₁₂. Furthermore, dietary habits of subjects adhering more to this DP were characterized as high intake of salad dressing, nuts, fish, tomatoes, poultry, cruciferous vegetables, fruits, and dark and green leafy vegetables and low intake of high-fat dairy, red meat, organ meat, and butter.

We previously reported that higher adherence to the MeDi was associated with reduced risk of AD in this WHICAP population.^5-6 However, this multiethnic population may not strictly consume foods typical of the ones consumed in Mediterranean countries. Hence, one goal of the present study was to see whether there are "naturally existing" DPs in our population that may also be associated with AD risk. Interestingly, the identified protective DP 2 was very similar to the MeDi,^5-7,47 and they are correlated with each other (Pearson r = 0.35; P < .001). Nevertheless, from another point of view, this means only about 12% of DP 2's variance was shared by the MeDi, indicating that despite some overlap, important new information was obtained in the current study. For example, rather than treating each food group equally in MeDi, the factor loadings of food–DP 2 help to identify the relative importance of each food group, thus providing more specific information.

So, as far as individual nutrients: omega-3 fats, omega-6 fats, vitamin E, and folate are good, but with lower SFA and vitamin B_12. In terms of actual foods: high intake of salad dressing, nuts, fish, tomatoes, poultry, cruciferous vegetables, fruits, and dark and green leafy vegetables are good, along with low intake of high-fat dairy, red meat, organ meat, and butter. (See what I did there - green means go, red means stop.)

As they note, this is similar to, but not identical with, the Mediterranean Diet, which these researchers have also looked at:

Scarmeas N, Stern Y, Tang MX, Mayeux R, Luchsinger JA. Mediterranean diet and risk for Alzheimer's disease. Ann Neurol. 2006;59(6):912-921. FULL TEXT | WEB OF SCIENCE | PUBMED Scarmeas N, Stern Y, Mayeux R, Manly JJ, Schupf N, Luchsinger JA. Mediterranean diet and mild cognitive impairment. Arch Neurol. 2009;66(2):216-225. FREE FULL TEXT Scarmeas N, Luchsinger JA, Mayeux R, Stern Y. Mediterranean diet and Alzheimer disease mortality. Neurology. 2007;69(11):1084-1093. FREE FULL TEXT

Good to know - although I have been promoting foods such as these for several years as part of a healthy diet for body and brain.

Tags: Alzheimer Disease, nutrition, food, Health, dietary patterns, JAMA, Archives of Neurology, Food Combination and Alzheimer Disease Risk, A Protective Diet, omega-3 fats, omega-6 fats, vitamin E, folate, salad dressing, nuts, fish, tomatoes, poultry, cruciferous vegetables, fruits, dark and green leafy vegetables