Linoleic acid is a naturally occurring omega-6 essential fatty acid, present in a variety of foods, including the oils of seeds and nuts, such as sunflower, safflower, soya, corn seeds or walnuts.
In the 1970s, three separate trials were conducted, looking at dietary linoleic acid as a treatment for people with multiple sclerosis. Two of the trials gave participants 17 grams daily of linoleic acid in the form of sunflower oil with 8g daily of olive oil as the control substance. The third trial gave participants 23g daily of linoleic acid in the form of a sunflower spread, with the control group receiving 16g of olive oil spread daily. Two of the trials looked only at relapsing remitting MS, one trial also included people with progressive MS.
Results from these trials showed that people receiving linoleic acid had slower accumulation of disability over time. This was most noticeable in people who had little or no disability when they started on the trial, suggesting that linoleic acid was of most benefit to people who are newly diagnosed. Linoleic acid did not appear to affect the number of relapses that people had, but those people who received linoleic acid experienced shorter relapses, whatever their level of disability when the trials started. There is no evidence that increasing linoleic acid benefits people with progressive MS as an insufficient number of people with this type of MS were included in the trials.
What is the best dose of linoleic acid?
The trials gave people with multiple sclerosis 17-23g daily of either sunflower spread or sunflower oil. However, it was noted by the researchers that it was unclear whether this was the optimum amount of linoleic acid. For people who have a poor appetite, or who are trying to lose weight, these levels may well not be desirable. Other downsides of linoleic acid can be that the oily taste may be unpleasant and it can cause diarrhoea in some people.
Linoleic acid should be considered in the context of a balanced diet, which is low in total fat and includes five portions of fruit and vegetables a day.
Sources of linoleic acid
Sources include full fat sunflower margarine or sunflower, safflower or sesame seed oils, which can be incorporated into the diet as salad dressings or as a spread. To get the benefit of the linoleic acid, oil or spreads should not be heated, and should be stored in cool, dark conditions. Alternatively, or additionally, supplements can be taken, although it may be difficult to consume enough linoleic acid in this way.
The following each provide 3.5-4.5g of linoleic acid, or a fuifth of the suggested daily intake.
- 3 level teaspoons (12g) of full fat polyunsaturated margarine, for example, sunflower, corn, safflower or soya;
- 2 teaspoons (8g) of corn oil, cotton seed oil, soya oil, walnut oil or wheatgerm oil;
- 1 teaspoon of safflower oil or sunflower oil;
- 10-15g of walnuts, brazil nuts, sesame, sunflower, pumpkin or poppy seeds;
- 20-30g of peanuts, peanut butter or almonds;
- 2 teaspoons (10g) of full fat mayonnaise;
- 30g of full fat soya flour;
- 35g of taramasalata or soya dessert topping;
- 5.8g (5,800mg) blackcurrant seed oil supplement (including gamma linolenic acid (GLA) content);
- 4.5g (4,500mg) evening primrose oil supplement (including gamma linolenic acid (GLA) content);
- 5.3g (5,300mg) grape seed oil supplement.
NB. Supplements are more expensive than dietary sources of linoleic acid. If in doubt ask your GP or consultant for a referral to a dietician.
Gamma linolenic acid (GLA)
There is some theoretical evidence that another omega-6 essential fatty acid, GLA, may also be beneficial in multiple sclerosis. Animal studies show that GLA suppresses immune system activity and decreases the severity of an MS-like disease. However, these benefits have not been replicated in human studies. The main source of GLA is evening primrose oil, which contains around 8-10% GLA and approximately 70% linoleic acid. Obtaining enough GLA or linoleic acid through evening primrose oil capsules alone is very difficult. There are no evidence-based recommendations for dosages of GLA.
- Neurology 1984;34:1441-1445. Summary Linoleic acid and multiple sclerosis: a reanalysis of three double-blind trials.
- Cochrane Database of Systematic Reviews 2012, Issue 12. Art. No.: CD004192. Full article Dietary interventions for multiple sclerosis.
- Cambridge: The Royal Society of Chemistry; 2002. McCance and Widdowson's the Composition of Foods. 6th ed.
- New York: Demos; 2007. Complementary and alternative medicine and multiple sclerosis. 2nd ed.
Last updated: December 2017
Last reviewed: November 2014
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