Studies of Linoleic Acid.
The are many MS-related studies of linoleic acid supplementation. In an animal model of MS, deficiencies in linoleic acid appear to be harmful, while supplements have proved beneficial.
In the 1970s, three randomized, blinded, placebo-controlled studies of linoleic acid supplementation were completed in people with MS. In all three studies, sunflower seed oil was used. One study reported no benefit from treatment. The other two noted significant decreases in the severity and duration of the attacks, while frequency and overall progression of disability remained unchanged.
When the data from the three studies were pooled together and analyzed in 1984, several findings were reported. The three studies combined provided data on 172 subjects. It was reported that people with little or no disability at the start of treatment had a slowed progression of MS. Linoleic acid was associated with decreased duration and severity of attacks, regardless of the severity of the disease when treatment began. Some of the statistical methods employed when analyzing the pooled data have been questioned.
The data concerning the beneficial effects of linoleic acid on MS are suggestive but not definitive.
Sources of Linoleic Acid.
Seeds and nuts, and oils from seeds and nuts, are high in linoleic acid. These include safflower seed oil, sesame seed oil, and sunflower seed oil. Flaxseed oil, also known as linseed oil, has linoleic acid as well as omega-three fatty acids.
By consuming more of these foods in the diet, including oils, one can increase linoleic acid intake. Oil supplements are another, more aggressive method. The ideal dosage of linoleic acid has not been determined, nor has the optimal ratio of omega-six to omega-three fatty acids. The dosage that is sometimes recommended is four teaspoons of oils containing linoleic acid. These oils should be stored in cool, dark places and should not be heated before consumption. Many people enjoy them on salads or mixed in with vegetables or dairy products.
Risks of Linoleic Acid.
There is a concern that linoleic acid supplementation may increase the risk of some cancers. Although this issue is not fully resolved, a 1998 review evaluating all research on linoleic acid supplementation found it unlikely that there was an increased risk of cancer.
Linoleic acid supplementation can also produce several other side effects. These may include an unpleasant oily taste, diarrhea, and increased triglyceride levels in certain people. Polyunsaturated fatty acids may also produce a deficiency in vitamin E, which may be avoided through supplementation with low doses of vitamin E.
Vitamin E and Polyunsaturated Fatty Acids
It is important to note that polyunsaturated fats may decrease levels of vitamin E in the body. If large quantities of polyunsaturated fat are taken, vitamin E intake must be increased. High doses are not necessary—in fact, as an antioxidant, they may even have negative consequences for people with MS. Many suggest that 0.6 to 0.9 international units (IU) of vitamin E be consumed for every gram of polyunsaturated fatty acid.
References and Additional Reading
Bowling AC. Complementary and Alternative Medicine and Multiple Sclerosis. New York: Demos Medical Publishing, 2007.
Bowling AC, Stewart TS. Dietary Supplements and Multiple Sclerosis: A Health Professional’s Guide. New York: Demos Medical Publishing, 2004.
Jellin JM, Batz F, Hitchens K, et al. Natural Medicines Comprehensive Database. Stockton, CA: Therapeutic Research Faculty, 2009.
Ulbricht CE, Basch EM, eds. Natural Standard Herb and Supplement Reference: Evidence-Based Clinical Reviews. St. Louis: Elsevier-Mosby, 2005.