Three studies from the 1980s showed that polyunsaturated fats in the form of an omega-6 fatty acid, linoleic acid, can slow progression of MS, but all their results were inconclusive.1-3 None of the studies reduced the patients’ intake of saturated fats, and the control groups were given oleic acid, or olive oil. Olive oil has been shown to reduce the severity of experimental autoimmune encephalomyelitis (EAE), an animal model of MS.4
Moreover, the numbers in each individual study were too small to achieve a statistically significant effect. So investigators pooled the results and looked at the overall effect, allowing for differences between the studies.5 They showed a statistically significant decrease in the rate of deterioration with linoleic acid supplementation for those who had little to no disability at the study’s start.
A 1987 trial by FitzGerald and co-workers looked at the effects of nutritional counseling on MS outcomes.7 The investigators were working on behalf of a group called ARMS (Action for Research into Multiple Sclerosis), which was formed by people with MS who were distressed by the lack of available therapies. Judy Graham, who wrote the excellent book Multiple Sclerosis: A Self-Help Guide to Its Management (8) was one of them.
They approached a group of researchers at the Central Middlesex Hospital in London, hoping to advance research and devise therapies. Their thrust was dietary. Professor Michael Crawford, Professor of Nutrition at Nottingham University, developed a diet high in essential fatty acids with a good amount of vitamins and minerals.
The study began with 200 people, but the diet, testing and analyses were quite rigorous, and after 34 months just 83 people remained. They were counseled to avoid saturated fats and increase polyunsaturated fats and antioxidants:
The investigators monitored levels of the fats in the blood to prove that the good dieters did modify their diet.
Some of the same investigators who had done the omega-6 work decided to do a randomized controlled trial (RCT) to test this.9 The small group size was an issue. Also, the investigators felt they couldn’t ethically use a placebo inactive treatment because omega-6s had already been shown to work. So the control group took omega-6s.
Once again, there was no strict avoidance of animal fats, but patients were advised to “encourage a low intake of animal fat and a plentiful intake of omega-6 fatty acids.” So there is no record of how much animal fat patients in each group had, and the untreated group actually received omega-6 fatty acids – which had previously been shown to work in MS. So did the group treated with the omega-3 fatty acids.
Not surprisingly, the investigators failed to find a significant difference between groups. If omega-3s were better, one would expect to see improvements in both groups, but greater improvements in the omega-3 group. At two years, the omega-3 group did better:
Although the researchers were ethically right in not asking the control group patients to miss out on the benefits of dietary changes, this decision almost certainly cost them the chance to identify a difference between groups that could be regarded as “proof.”
The first RCT of diet in MS, as mentioned in the Diet and MS section, found a statistically significant improvement in the group that took fish oil, with 0.8 fewer relapses per year.10 A Dutch review in 2005 concluded that fish oil may be beneficial in MS, both through its immune mechanism of action and through structural effects within the CNS.11
More recently, OMS undertook its own research into the subject via the extensive, international HOLISM study, which involved more than 2,500 participants from 57 countries. The findings strongly supported a link between consumption of fish and omega-3 supplements and better health for people with MS. Specifically, people with MS taking flaxseed oil regularly had over 60% fewer relapses than those who did not, and they experienced other health benefits, including better quality of life.12
1. Millar JH, Zilkha KJ, Langman MJ, et al. Double-blind trial of linoleate supplementation of the diet in multiple sclerosis. Br Med J 1973; 1:765-768
2. Paty DW, Cousin HK, Read S, et al. Linoleic acid in multiple sclerosis: failure to show any therapeutic benefit. Acta Neurol Scand 1978; 58:53-58
3. Bates D, Fawcett PR, Shaw DA, et al. Polyunsaturated fatty acids in treatment of acute remitting multiple sclerosis. Br Med J 1978; 2:1390-1391
4. Meade CJ, Mertin J, Sheena J, et al. Reduction by linoleic acid of the severity of experimental allergic encephalomyelitis in the guinea pig. J Neurol Sci 1978; 35:291-308
5. Dworkin RH, Bates D, Millar JH, et al. Linoleic acid and multiple sclerosis: a reanalysis of three double-blind trials. Neurology 1984; 34:1441-1445
6. Excellence. NIfC. Multiple sclerosis. Management of multiple sclerosis in primary and secondary care. London: National Institute for Clinical Excellence, 2003
7. Fitzgerald G, Harbige LS, Forti A, et al. The effect of nutritional counselling on diet and plasma EFA status in multiple sclerosis patients over 3 years. Hum Nutr Appl Nutr 1987; 41:297-310
8. Graham J. Multiple sclerosis: a self-help guide to its management. Northamptonshire: Thorsons, 1987
9. Bates D, Cartlidge NE, French JM, et al. A double-blind controlled trial of long chain n-3 polyunsaturated fatty acids in the treatment of multiple sclerosis. J Neurol Neurosurg Psychiatry 1989; 52:18-22
10. Weinstock-Guttman B, Baier M, Park Y, et al. Low fat dietary intervention with omega-3 fatty acid supplementation in multiple sclerosis patients. Prostaglandins Leukot Essent Fatty Acids 2005
11. van Meeteren ME, Teunissen CE, Dijkstra CD, et al. Antioxidants and polyunsaturated fatty acids in multiple sclerosis. Eur J Clin Nutr 2005; 59:1347-1361
12. Jelinek GA, Hadgkiss EJ, Weiland TJ, et al. Association of fish consumption and omega-3 supplementation with quality of life, disability and disease activity in an international cohort of people with multiple sclerosis. Int J Neurosci 2013;Epub ahead of print