Multiple Sclerosis: Nutritional Considerations

Several dietary factors have emerged in studies on the risk of developing MS or on its progression after diagnosis: 

Supplemental Vitamin D

Limited evidence suggests that vitamin D may play a preventive role. In the Nurses’ Health Study I and II, regular use of a vitamin D supplement, typically within a multiple vitamin, resulted in a 40% reduction in MS risk.⁵ The effect of vitamin D may be related to an increase in the anti–inflammatory cytokine TGF–β and a reduction in Th1 cells that are known to be involved in the progression of autoimmune diseases, including MS.²²

Low Saturated Fat Diet

Several investigations testing the impact of diet in MS etiology have noted a higher prevalence of MS in correlation with greater intakes of energy, fat, and protein.²³ Specifically, higher intake of saturated fat found in foods of animal (not plant) origin, including meat, milk, butter, and eggs, was associated with the prevalence of MS.²³ The incidence of MS is low in Japan and in various African countries, where saturated fat intake is typically very low.^24–26

There are several ways in which diets high in saturated fat might be involved in MS. One explanation suggests that meals high in saturated fat reduce oxygen availability to the CNS, resulting in activation of lysing enzymes in cells that may increase the permeability of the blood–brain barrier to potential toxins.²⁷ The tendency of saturated fats to elevate blood cholesterol concentrations may also play a role, as suggested by a reduction in MS lesions in patients treated with certain cholesterol–lowering drugs.²⁸ Saturated fats interfere with the conversion of essential fatty acids to their long–chain derivatives (eg, arachidonic acid [AA], eicosapentanoic acid [EPA], docosahexanoic acid [DHA]).²⁴ In turn, these derivatives influence the production of pro–inflammatory cytokines²⁹ that play key roles in MS.²⁴

Additionally, evidence indicates that during relapse, both low density lipoprotein (LDL) oxidizability and autoantibodies to oxidized LDL are increased.³⁰ The known pro–inflammatory effects of oxidized LDL³¹ might explain the relationship between saturated fat–induced increases in LDL and MS. The reduced amount of LDL that would be expected in the blood of patients on diets very low in saturated fat might explain the benefit of such a diet in MS.

In 1948, neurologist Roy Swank, of the Montreal Neurological Institute hypothesized that a low–saturated–fat diet would retard the progression of MS and tested this diet in 264 people.²⁷ His experimental diet restricted total and saturated fat intake, the latter to no more than 15 grams per day. It excluded dairy products that were more than 1% fat and fattier cuts of meat. The diet also included 15 grams of vegetable oils and 5 grams of cod liver oil daily, and patients could use an additional 5 grams of vegetable oils, as long as fat intake did not exceed 40 grams per day (not counting the small amounts of fat naturally present in cereal grains, fruits, and vegetables). He noted in a longitudinal study over 50 years that patients following this regimen strictly (ie, those who consumed no more than 30 grams of fat per day) experienced substantial decreases in MS exacerbation, lower mortality rates, and better functional capacity, compared with individuals whose fat intakes were higher.³² Although this study has been criticized for selection bias and a lack of controls, blinding, and randomization, the reported results are impressive. Diets that are low in total and saturated fat have additional benefits, including their potential to control obesity (which is a frequent finding in individuals with MS) and to reduce cardiovascular mortality.²³

Dairy Avoidance

Epidemiological studies have repeatedly associated milk and dairy product intake with MS prevalence. Two theories have emerged to attempt to explain this association. First, some evidence suggests that an immunologic phenomenon may be involved. MS patients are known to have an enhanced antibody response to myelin oligodendrocyte glycoprotein (MOG).³³ These antibodies have been found to cross–react with the bovine milk protein butyrophilin, a process that would not normally occur due to the development of oral tolerance to this protein early in life. Some have suggested that, when gastrointestinal infections or other factors prevent the development of oral tolerance, exposure to butyrophilin early in life may lead to susceptibility to MS. A second theory suggests that dairy calcium may suppress the production of 1,25(OH)2D3,³⁴ the active hormone form of vitamin D that may be protective against MS, as noted above.

Lipid–Supplemented Diets

Several studies have revealed lower levels of essential fatty acids (eg, linoleic acid, an omega–6 fatty acid) or long–chain omega–3 fatty acids (eg, EPA) in red blood cells, adipose tissue, plasma lipids, and CSF of patients with MS.²³ Theoretically, supplementation with linoleic acid might be of benefit not only by preventing deficiency, but also by suppressing the Type I immune response35 that partly characterizes the immune response in MS.³⁶

However, clinical trials of omega–6 fatty acid treatment for MS have not yielded convincing results. These studies provided patients with 17 to 20 grams of sunflower oil per day in capsule form for 24 to 30 months.

Numerous trials have been conducted in which omega–3 fatty acid supplements (eg, fish oils, EPA and DHA acid, 6 to 10 grams per day for 1 to 2 years) were given to patients with MS, and symptoms rated on the Disability Status Score (DSS). Both the quality of evidence and outcome of these studies have been reviewed by the Agency for Healthcare Research and Quality (AHRQ).³⁷ AHRQ concluded that, although some trials with weaker study designs found a reduction in MS incidence or progression, aggregate data are insufficient to draw conclusions about the effects of omega–3 fats on MS incidence, and evidence regarding the progression of MS is inconsistent and inconclusive.³⁷ The benefit, if any, of therapy for MS with fatty acid supplements remains to be proven.

Orders

See Basic Diet Orders chapter.

A low saturated fat (<10 g/day), low cholesterol diet may be tried prospectively. This is most effectively accomplished with a low–fat, vegan diet.

Nutrition consultation will be helpful in implementing this diet and arranging outpatient follow–up.

Smoking cessation.

Stress reduction exercises, such as yoga, meditation, or other activities may be useful.

What to Tell the Family

Although there is no known cure for MS, some clinical studies show that disease progression may be slowed if the saturated fat intake is less than 10 grams daily. Family members can assist the patient in reducing saturated fat, and may improve their own health by following a similar diet. Limiting or avoiding animal products (red meat, chicken, fish, eggs, and dairy products) and tropical oils (palm, palm kernel, and coconut) is usually necessary to reach this goal, and a nutritionist can aid in following this diet regimen.