In the study, published in JAMA Neurol in July and conducted by Harvard researchers, the 20% of consumers who had the highest levels of omega-3s in their diets were a third less likely than to develop the fatal disease the 20% who ate the lowest amount of omega-3 fatty acids.
Amyotrophic lateral sclerosis (ALS), known in America as Lou Gehrig’s disease, is a rapidly progressing neurological disease that attacks the nerve cells that control voluntary muscles. It is one of the most common neuromuscular diseases worldwide, affecting people of all races and ethnic backgrounds. Renowned physicist Professor Stephen Hawking suffers from this disease.
The study, led by Kathryn Fitzgerald of the Harvard School of Public Health, examined the association between consumption of ω-3 and ω-6 PUFAs and risk of ALS in an analysis of data collected from more than a million people who participated in five previously published studies.
They knew that diet-derived long chain polyunsaturated fatty acids (PUFAs) are incorporated into brain lipids and modulate oxidative and inflammatory processes, thus influencing ALS risk and progression, although limited data was available.
The researchers documented 995 ALS cases during the follow-up, ranging from nine to 24 years of age. A higher intake of ω-3 PUFA was associated with a reduced risk of ALS. Consumption of both α-linolenic acid (ALA, which is found in vegetable sources and nuts) and marine ω-3 PUFAs contributed to this association. The use of ω-6 PUFAs was not associated with an ALS risk.
Diet was assessed through questionnaires. In men, the median -3 PUFA intake ranged from 1.40 to 1.85 grams (g) / day (d) and the median ω-6 PUFA intake ranged from 11.82 to 15.73 g / d. In women, the median -3 uptake ranged from 1.14 to 1.43 g / d and the median ω-6 PUFA uptake in the range from 8.94 to 12.01 g / d.
“Overall, the results of our large prospective cohort study suggest that people with a higher food intake totaling ω-3 PUFA and ALA have a lower risk of ALS,” the paper says.
Further research, possibly with biomarkers of PUFA uptake, should be done to confirm these results and determine whether high ω-3 PUFA uptake could be beneficial in people with ALS, the researchers suggest.
The research was supported by grants from the National Institute of Neurological Diseases and Stroke, the National Cancer Institute, and the ALS Therapy Alliance Foundation.
Michael Swash, MD, of the Royal London Hospital, England, said: “Fitzgerald and colleagues suggest that the fatty acid composition of cell plasma membranes, which could be measured in the erythrocyte membranes, may help modulate oxidative stress responses, excitotoxicity and inflammation, all factors that have been linked to ALS and other neurodegenerative diseases. “
“As a precautionary measure, and contrary to their results, the authors note that in a mouse model of ALS pretreatment with high doses of eicosapentanoic acid, a long-chain ω-3 PUFA, disease progression was accelerated,” added Swash.
doi: 10.1001 / jamaneurol.2014.1214
“Food ω -3 intake of polyunsaturated fatty acids and risk of amyotrophic lateral sclerosis”
Authors: Kathryn C. Fitzgerald, MSc; Alice J. O’Reilly, ScD; Guido J. Falcone, MD; et al.