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Fatty acids may help PMS

A supplement of essential fatty acids seems to help women with premenstrual syndrome, a new study shows. But the study is small and we need more research to back up the results.

What do we know already?

Premenstrual syndrome is the name given to a group of symptoms that some women experience in the week before their period starts. These include mood swings, anxiety, feeling bloated, and having sore breasts. The symptoms usually go away shortly after the menstrual period begins.

One popular remedy for premenstrual syndrome is evening primrose oil, a type of essential fatty acid (this means a type of fatty acid not produced by the body). However, there's not been much good research into evening primrose oil, and the research that has been done suggests that it doesn't work.

This new study looked at a supplement including several fatty acids and nutrients: gamma linolenic acid, oleic acid, linoleic acid, other polyunsaturated acids, and vitamin E. The study involved 120 women, who were randomly assigned to take either a high dose (2 grams daily), low dose (1 gram daily), or 2 grams of mineral oil (as a placebo).

All the women recorded their symptoms in a standard questionnaire before the study began, then three and six months after they started taking treatment.

What does the new study say?

After three months of treatment, the women taking fatty acids said their symptoms had improved. They felt better before their periods than they did at the start of the study, and were also doing better than the women taking mineral oil.

The women taking mineral oil also said their symptoms had improved after three months, but not by as much as the women taking fatty acids. Also, their symptoms had gone back to pre-study levels after six months of treatment, while the women taking fatty acids saw their symptoms continue to improve.

Women taking 2 grams of fatty acids had a bigger improvement in symptoms than women taking 1 gram.

How reliable are the findings?

This was a randomised controlled trial, which is the best type of study to find out whether a treatment works or not. As such, the results are likely to be fairly reliable. However, other studies looking at one type of fatty acid (evening primrose oil) have not found these results. So, we need to see more trials, preferably with more women taking part, to be sure we can rely on the results.

Where does the study come from?

The study was done by researchers in Brazil and published in the journal Reproductive Health, owned by BioMed Central. The fatty acids were given free by their manufacturer, although the researchers were not paid by them.

What does this mean for me?

If you suffer from premenstrual syndrome, you may feel any potential treatment is worth a try. This study suggests that fatty acid supplements may be helpful, although we can't be sure. It's best to talk to your doctor if you plan to take supplements for a condition, to make sure they don't affect any other medical condition or treatment you are taking.


Rocha Filho EA, Lima JC, Pinho Neto JS, et al. Essential fatty acids for premenstrual syndrome and their effect on prolactin and total cholesterol levels: a randomized, double blind, placebo-controlled study. Reproductive Health. 2011; 8: 2.

Jan 21, 2011