NUTRITIONAL FACTORS IN THE ETIOLOGY OF MULTIPLE-SCLEROSIS - A CASE-CONTROL STUDY IN MONTREAL, CANADA

Background It has been suggested that nutrition and food patterns, par ticularly high consumption of animal fat and low intake of fish produc ts, may play a role in the aetiology of multiple sclerosis (MS). Metho ds The relation between nutritional factors and MS was studied among 1 97 incident cases and 202 frequency matched controls in metropolitan M ontreal during 1992-1995. Dietary information was collected by employi ng a 164-item food frequency questionnaire in a face-to-face interview . Results An inverse association was observed between high body mass i ndex (BMI) and the risk of MS, with an odds ratio (OR) of 0.76 (95% co nfidence interval [CI] : 0.61-0.95), per 5-unit increase in BMI, both sexes combined. In addition, taller women showed a greater risk for MS ; the OR per 10 cm increase in height was 1.58 (95% CI: 1.06-2.35). In continuous variable analyses, using the difference between the lowest and highest quartile of intake as a unit, a positive association was observed with energy and animal fat intake. The OR per 897 kcal increa se was 2.03 (95% CI: 1.13-3.67) and 1.99 (95% CI: 1.12-3.54) per 33 g of animal fat intake above the baseline. A significant protective effe ct was observed with other nutrients, including vegetable protein, die tary fibre, cereal fibre, vitamin C, thiamin, riboflavin, calcium, and potassium. Similar trends were seen for males and females when analys ed separately. With respect to specific foods (as opposed to nutrients ), a higher intake of fruit juices was inversely associated with risk (OR = 0.82; 95% CI:0.74-0.92). A protective effect was also observed w ith cereal/breads intake for all cases combined (OR = 0.62; 95% CI:0.4 0-0.97) and for fish among women only; pork/hot dogs (OR = 1.24; 95% C I: 1.02-1.51) and sweets/candy (OR = 1.29; 95% CI: 1.07-1.55) were pos itively associated with risk. Conclusion The study generally supports a protective role for components commonly found in plants (fruit/veget ables and grains) and an increased risk with high energy and animal fo od intake.