Polyunsaturated fatty acids and the risk of multiple sclerosis.
BACKGROUND
Results from previous studies on polyunsaturated fatty acid (PUFA) intake and multiple sclerosis (MS) risk are conflicting.


OBJECTIVE
To prospectively investigate the association between dietary intake of PUFA and MS risk.


METHODS
We followed 80,920 women from Nurses' Health Study (1984-2004) and 94,511 women from Nurses' Health Study II (1991-2009) who reported on diet using a validated food frequency questionnaire every 4 years and identified 479 incident MS cases during follow-up. We used Cox regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs), for the effect of PUFA intake on MS risk adjusting for age, latitude of residence at age 15, ancestry, cigarette smoking, supplemental vitamin D intake, body mass index, and total energy intake.


RESULTS
Higher intake of total PUFA at baseline was associated with a lower risk of MS (HR top vs bottom quintile: 0.67, 95% CI: 0.49-0.90, p trend = 0.01). Among the specific types of PUFA, only α-linolenic acid (ALA) was inversely associated with MS risk (HR top vs bottom quintile: 0.61, 95% CI: 0.45-0.83, p trend = 0.001). The long-chain fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were not associated with MS risk.


CONCLUSIONS
Low dietary PUFA intake may be another modifiable risk factor for MS.
Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway/Norwegian Multiple Sclerosis Competence Centre, Department of Neurology, Haukeland University Hospital, Bergen, Norway.
Kjetil
K
Bjørnevik
Partners Multiple Sclerosis Center, Brigham and Women's Hospital, Boston, MA, USA.
Tanuja
T
Chitnis
Departments of Nutrition and Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA/Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.
Alberto
A
Ascherio
Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
Kassandra L
KL
Munger
D000328:Adult; D000368:Aged; D004041:Dietary Fats / Q000494:pharmacology*; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000453:epidemiology / Q000517:prevention & control*; D017962:alpha-Linolenic Acid / Q000494:pharmacology*
D004041:Dietary Fats; D005231:Fatty Acids, Unsaturated; D017962:alpha-Linolenic Acid
Multiple sclerosis; alpha-linolenic acid; epidemiology; polyunsaturated fatty acids; risk factors