Dietary fatty acids and the risk of Parkinson disease. The Rotterdam study.
De Lau LML, Bornebroek M, Witteman JCM, Hofman A, Koudstaal PJ and Breteler M;
Commented by , 22 Aug 2005
Background
The role of nutrition, particularly of high intake of certain nutrients, such as vitamins and fatty acids have been always a hot topic with regard to the risk of brain disorders and neurodegeneration, the results have been mixed and controversial. This study investigated the association between dietary fatty acids and the risk of Parkinson disease.
Aims of the study
The objective of this study was to determine if a high intake of unsaturated fatty acids might be associated with a lower risk of Parkinson disease (PD).
Methods
This investigation was part of the large Rotterdam Study, which is a prospective, population-based cohort study of people aged 55 years or more. The association between intake of unsaturated fatty acids and the risk of incident PD was evaluated in a cohort of 5,289 subjects who were free of dementia and parkinsonism at baseline.
They underwent complete dietary assessment and PD was subsequently assessed through repeated in-person examination, the cohort was continuously monitored by computer linkage to medial records. The data were analyzed using Cox proportional hazards regression model.
Results
After a mean follow-up of 6 years, 51 subjects were diagnosed with incident PD. Intakes of total fat, monounsaturated fatty acids (MUFAs), and polyunsaturated fatty acids (PUFAs) were significantly associated with a lower risk of PD, with an adjusted hazard ratio per SD increase of energy-adjusted intake of 0.69 (95% CI 0.52 to 0.91) for total fat, of 0.68 (95% CI 0.50 to 0.94) for MUFAs, and 0.66 (95% CI 0.46 to 0.96) for PUFAs.
No associations were found for dietary saturated fat, cholesterol, or trans-fat. The authors suggested that high intake of unsaturated fatty acids might protect against Parkinson disease.
Professor Emre’s comments
Nutrition, especially the role of fat, vitamins and dietary supplements has been a popular topic with regard to neurodegenerative diseases.
As opposed to some established associations between vascular diseases and nutrition, the link between diet and neurodegenerative diseases has been controversial with many myths surrounding the topic, and making the lay public susceptible to potential misguidance by marketers.
There are enough theoretical grounds to assume a role for fatty acids in health and disease of the brain, unsaturated fatty acids are important constituents of neural cell membranes and have neuroprotective, antioxidant and anti-inflammatory properties in different models (ref. 1; ref. 2; ref. 3).
Despite these theoretical benefits epidemiological data on the association between dietary fat intake and the risk of PD have been inconsistent (see ref. 4). Most of the previous studies were based on retrospective assessment of dietary habits, the strength of this study is its prospective design, the dietary habits were assessed before the onset of PD and incident cases were evaluated.
The results demonstrated a significant association between consumption of unsaturated fatty acids and reduced risk of PD, giving another reason for the adoption of a "healthy" dietary style.
Surprisingly, although statistically not significant, the results also suggested a trend for an inverse association between saturated fatty acids and the risk of PD, which may be simply by chance.
Nevertheless, it is not advisable to use the latter as a protective strategy with all the other known hazards of saturated fats; it would be wiser to stick to the unsaturated fatty acids!
References
1. Kim HY, Akbar M, Kim KY. Inhibition of neural apoptosis by polyunsaturated fatty acids. J Mol Neurosci 2001; 16; 223-227 and 279-284.
2. Blok WL, Katan MB, van der Meer JW. Modulation of inflammation and cytokine production by dietary (n-3) fatty acids. J Nutr 1996; 126; 1515-1533
3. Youdim KA, Martin A, Joseph JA. Essential fatty acids and the brain: possible health implications. Int J Dev Neurosci 2000; 18; 383-399
4. Chen H, Zhang SM, Hernan MA, Willett WC, Ascheria A. Dietary intakes of fat and risk of Parkinson's disease. Am J Epidemiol 2003; 157; 1007-1014