Lisa suggested I share some of my findings in researching the MS literature over the last decade. Here is my take on one of the many positive trials showing the benefits of a low saturated fat diet in MS. Most of these studies were uncontrolled, that is there was no control group. But in 2005, a randomized controlled trial on dietary fat in MS was published.(1) This was unfortunately only a very small study of limited duration but is an important addition to the evidence base on dietary fats in MS. In a one-year study, 31 patients with relapsing-remitting MS were assigned to a low-fat diet (15% of calories) supplemented with fish oil or the standard American Heart Association heart diet in which fat made up 30 per cent of calories, supplemented with olive oil.

Clearly there are problems with this study which might weaken the dramatic effects seen in Professor Swank's landmark 34 year study of a low saturated fat diet in MS.(2) Firstly it was a relatively short study: the maximal benefit of diet in Swank's study did not occur until at least the three-year mark. Secondly, the fat reduction was not specifically directed at saturated fat, and both groups lowered their fat intake. Thirdly, it was a small study: only 27 patients were available for analysis of the 31 enrolled. Lastly, olive oil is likely to have some benefit based on animal work in experimental MS, so should not have been used as a control treatment. Additionally, only around two-thirds of the participants were able to stick to their diets.

Despite these issues, the study showed that patients felt better according to standard MS quality of life questionnaires. But more importantly, their relapse rates fell quite significantly from pre-trial rates, more so for the fish oil group. In fact the fish oil group had a mean relapse rate of 1.14 relapses per year in the year prior to the trial, and dropped by 0.79, a reduction of 69 per cent, and the olive oil group had a pre-trial rate of 1.17 which dropped by 0.69, a 59 per cent reduction. These findings were statistically significant despite the small numbers of participants. Interestingly, the drop of 69 per cent for the low-fat plus fish oil group is remarkably similar to the relapse rate reduction in the first year of Swank's study. This should really give us confidence that the findings in Swank's study were real.

The authors concluded that despite the study limitations, a low-fat diet supplemented with omega-3 fatty acids may complement the beneficial effects of concurrent disease-modifying therapies. They suggested this because virtually all patients were on disease-modifying drugs for the year prior and the year of the study. The 69 per cent relapse rate reduction associated with the diet compares very favorably with the reduction of about 30 per cent for these drugs in the major clinical trials. The MS community is crying out for more well-designed research in the area, and researchers have speculated that with more research diet may well become standard treatment.(3) It is interesting to note that the Oregon Health and Science University is now enrolling patients in a major randomized controlled trial of a low saturated fat diet in MS (see http://www.facebook.com/MultipleSclerosisManagement?ref=ts).