High-Fiber, Low-Saturated-Fat Diet May Protect Against Parkinson's Disease

December 6, 2007 — A dietary pattern of high intake of fruits, vegetables, legumes, whole grains, nuts, fish, and poultry; low intake of saturated fat; and moderate intake of alcohol may protect against Parkinson's disease (PD), according to the results of a prospective study reported in the December issue of the American Journal of Clinical Nutrition.
"Several studies have shown associations between Parkinson Disease (PD) risk and individual foods and nutrients with inconsistent results," write Xiang Gao, PhD, from the Harvard School of Public Health in Cambridge, Massachusetts, and colleagues. "We examined associations between dietary patterns and risk of PD in the Health Professionals Follow-Up Study (1986 - 2002) and the Nurses' Health Study (1984 - 2000)."
Using principal components analysis to determine major dietary patterns and the Alternate Healthy Eating Index (AHEI) and the alternate Mediterranean Diet Score (aMED) to evaluate diet quality, the investigators studied 49,692 men and 81,676 women who were free of PD at baseline. Cox proportional hazards models were used to compute relative risks (RRs) within each cohort, and these were pooled with a random-effects model.
After 16 years of follow-up, there were 508 new cases of PD. Two dietary patterns were identified by principal components analysis: prudent, characterized by high intakes of fruit, vegetables, and fish; and Western. The prudent, but not the Western, dietary pattern was inversely associated with the risk for PD. These associations were independent of smoking, intake of caffeine, and other risk factors for PD.
For the highest vs the lowest quintiles of the prudent score, the pooled multivariate-adjusted RR was 0.78 (95% confidence interval [CI], 0.56 - 1.07; P for trend = .04). For the highest vs the lowest quintiles of the AHEI, the pooled multivariate-adjusted RR was 0.70 (95% CI, 0.51 - 0.94; P for trend = .01), and for aMED it was 0.75 (95% CI, 0.57 - 1.00; P for trend = .07).
Limitations of the study include possible residual confounding by unknown risk factors, and dietary patterns defined by principal components analysis that were data-driven but not established a priori.
"Dietary patterns with a high intake of fruit, vegetables, legumes, whole grains, nuts, fish, and poultry and a low intake of saturated fat and a moderate intake of alcohol may protect against PD," the study authors write. "Benefits of a plant-based dietary pattern including fish to PD merit further investigation."
The National Institutes of Health/National Institute of Neurological Disorders and Stroke and the Intramural Research Program of the National Institutes of Health, National Institute of Environmental Health Sciences, supported this study. The study authors have disclosed no relevant financial relationships.
Am J Clin Nutr. 2007;86:1486-1494.