Click to Call
Food, Health, and Eco-news
Omega-3s Curbed PMS
Clinical trial found that fish oil reduced mental and physical symptoms 05/20/2013
It ain't easy being female.
Compared with men's relatively simple bodies, women's complex biology can generate far more grief.
In addition to the stresses and discomforts of menstruation, pregnancy, and menopause, some women suffer from premenstrual syndrome (PMS).
Estimates vary widely, but the American College of Obstetricians and Gynecologists believes that at least 85 percent of menstruating women suffer at least one PMS symptom.
PMS occurs more often in women between their late 20s and early 40s, who've delivered at least one child, and have a family history of mood disorders or postpartum depression.
The symptoms generally occur one to two weeks before a woman's period starts, and cease with the onset of menstrual bleeding.
They include acne, tender breasts, fatigue, insomnia, upset stomach, bloating, constipation, diarrhea, headache, backache, food cravings, joint or muscle pain, poor concentration or memory, mood swings, anxiety, and depression.
About five percent of PMS patients suffer from severe form called premenstrual dysphoric disorder (PMDD), which can seriously disrupt their personal and work lives.
The system regulating serotonin – a key neurotransmitter – may not respond as flexibly to the hormone swings of the menstrual cycle in women who suffer from PMDD or severe PMS … see “Women's Mood-Control System May Differ from Men's”.)
Fortunately, PMS symptoms disappear when a woman's monthly periods stop due to pregnancy, hysterectomy, or menopause.
Remedies and causes have been elusive
Although some drugs or herbs help some women, the search for broadly effective remedies hasn't borne much fruit.
Researchers have focused on analgesic drugs, hormonal drugs (birth control pills) and on herbs with anti-depressant or hormone-modulating properties.
A study published almost 30 years ago found that women with PMS abnormally high blood levels of the short-chain, plant-source omega-6 fatty acid known as linoleic acid or LA (Brush MG et al. 1984).
The scientists also found that blood levels of the medium-chain omega-6 fat known as gamma-linolenic acid (GLA) were lower than normal in PMS patients.
(The body generates GLA during its conversion of omega-6 LA to the long-chain omega-6 essential to human health, known as arachidonic acid or AA.)
This lack of GLA suggests that PMS sufferers have trouble converting dietary LA to GLA … a finding that's led many women to take evening primrose oil or borage oil, which are the richest supplemental sources of GLA.
Sadly, GLA has not proven to be a reliable PMS remedy.
The long-chain omega-3s found in human cells and in seafood (DHA and EPA) show evidence that they may help alleviate depression, anxiety, and inflammation-induced pain.
Because PMS is associated with mood problems and pain, some researchers speculate that one or both of these seafood source omega-3s might help.
Omega-3s for menstrual pain
Dysmenorrhea (menstrual pain) can happen to women of most any age.
To date, scientists have published four trials testing the effects of fish oils on dysmenorrhea … all of which found that fish oil produced significant relief (Harel Z et al. 1996; Sampalis F et al. 2003; Moghadamnia AA et al. 2010; Rahbar N et al. 2012).
Doctors believe that dysmenorrhea may be caused or exacerbated by high levels of pro-inflammatory, hormone-like messenger chemicals (prostaglandins) made in the uterus from omega-6 fatty acids.
Omega-6 fats compete with inflammation-moderating omega-3s for space in our cell membranes and immune processes, and the standard American diet is grossly overloaded with omega-6 fats from vegetable oils.
To learn about this critical but still-overlooked nutritional issue, see “America's Sickening ‘Omega Imbalance'” and the Omega-3 / Omega-6 Balance section of our news archive.
Prior evidence on omega-3s for PMS
The results of two epidemiological studies from Denmark showed that women with PMS were more likely to have low blood levels of omega-3s, and a low (hence, pro-inflammatory) omega-3/omega-6 ratio (Deutch B 1995; Deutch B 1996).
Before the Iranian clinical trial we report on today, the efficacy of omega-3s for easing PMS had only been tested in one other controlled trial.
The authors tested an unrefined krill oil against a refined fish oil … with no placebo group to serve as a control. Both groups (krill oil and fish oil) showed benefits.
But compared with the fish oil group, the krill oil group used fewer analgesic drugs and reported greater mood benefits.
While the results seem to support the value of omega-3s for PMS, its results should be taken with a grain of salt because the trial had not control group, and because was conducted and funded by a krill oil manufacturer.
To the extent we can believe the trial's outcomes, the superior effect of krill oil could be due to the different “packages” (phospholipid and ethyl ester) in which omega-3s occur in each of the two tested oils (Sampalis F et al. 2003).
Now, the results of a controlled clinical trial from Iran indicate that fish oil may help alleviate a wide range of PMS symptoms.
Iranian trial finds broad relief from fish oil
Researchers at the Tehran University of Medical Sciences recruited 184 PMS patients for a well-designed trial … randomized, double blind, placebo-controlled (Sohrabi N et al. 2013).
The women were divided into two groups, each assigned to a different daily regimen for three months (90 days):
  • Placebo capsules
  • Fish oil capsules providing 2 grams of omega-3s
The scientists gauged compared the severity and duration of the women's symptoms at the outset and again at two points: 45 days and 90 days:
  • After 45 days, the average severity of depression, anxiety, lack of concentration and bloating were significantly lower in the fish oil group.
  • After 90 days, the average severity of depression, anxiety, lack of concentration, bloating, nervousness, headache and breast tenderness were lower in the fish oil group.
As the researchers wrote, “It appears that omega-3 fatty acids may reduce the psychiatric symptoms of PMS including depression, nervousness, anxiety and lack of concentration and may also reduce the somatic symptoms of PMS including bloating, headache and breast tenderness.” (Sohrabi N et al. 2013)
The longer list of benefits seen after 90 days led them to add an important point: “These effects increased by longer duration of treatment.”
Absent a longer trial period, we cannot know whether the benefits would have increased further with longer use of fish oil.
But the outcomes after 90 days seem more than successful enough to warrant larger, longer trials.
It certainly can't hurt PMS patients to try fish oil and krill oil, and to eat ample amounts of fatty fish (e.g., twice a week or more).
After all, generous consumption of fish and their omega-3s (and vitamin D) clearly help ensure optimal cardiovascular, joint, immune, and brain health.
  • Brush MG, Watson SJ, Horrobin DF, Manku MS. Abnormal essential fatty acid levels in plasma of women with premenstrual syndrome. Am J Obstet Gynecol. 1984 Oct 15;150(4):363-6.
  • Deutch B. [Painful menstruation and low intake of n-3 fatty acids]. Ugeskr Laeger. 1996 Jul 15;158(29):4195-8. Danish.
  • Deutch B. Menstrual pain in Danish women correlated with low n-3 polyunsaturated fatty acid intake. Eur J Clin Nutr. 1995 Jul;49(7):508-16.
  • Harel Z, Biro FM, Kottenhahn RK, Rosenthal SL. Supplementation with omega-3 polyunsaturated fatty acids in the management of dysmenorrhea in adolescents. Am J Obstet Gynecol. 1996 Apr;174(4):1335-8.
  • Moghadamnia AA, Mirhosseini N, Abadi MH, Omranirad A, Omidvar S. Effect of Clupeonella grimmi (anchovy/kilka) fish oil on dysmenorrhoea. East Mediterr Health J. 2010 Apr;16(4):408-13.
  • Office on Women's Health / U.S. Department of Health and Human Services. Premenstrual syndrome (PMS) fact sheet. Accessed at
  • Rahbar N, Asgharzadeh N, Ghorbani R. Effect of omega-3 fatty acids on intensity of primary dysmenorrhea. Int J Gynaecol Obstet. 2012 Apr;117(1):45-7. doi: 10.1016/j.ijgo.2011.11.019. Epub 2012 Jan 17.
  • Sampalis F, Bunea R, Pelland MF, Kowalski O, Duguet N, Dupuis S. Evaluation of the effects of Neptune Krill Oil on the management of premenstrual syndrome and dysmenorrhea. Altern Med Rev. 2003 May;8(2):171-9.
  • Sohrabi N, Kashanian M, Ghafoori SS, Malakouti SK. Evaluation of the effect of omega-3 fatty acids in the treatment of premenstrual syndrome: A pilot trial. Complement Ther Med. 2013 Jun;21(3):141-6. doi: 10.1016/j.ctim.2012.12.008. Epub 2013 Jan 16.