An iron-rich diet lowers the risk of pre-menstrual syndrome (PMS) according to a new study published in the American Journal of Epidemiology (1).
The study is one of the first to investigate whether dietary mineral intake is linked with PMS. The diets of more than 3,000 American women were analysed, with women completing three food frequency questionnaires over a 10-year period. After 10 years, 1,057 of the women were diagnosed with PMS while 1,968 of the women were free from the condition. The researchers then compared the diets of the women with PMS with the diets of the women with no symptoms. The researchers adjusted for factors known to affect PMS such as calcium intake.
The results showed that non-heme iron intake is linked to a lowered incidence of PMS. Non-heme iron is the iron found in plant foods and supplements, rather than iron from animal foods. Senior research Elizabeth Bertone-Johnson said that the women who consumed the most non-heme iron from both foods and supplements had “a 30 to 40 percent lower risk of developing PMS than women who consumed the lowest amount of non-heme iron”. The results also showed that women with the lowest iron intake were almost twice as likely to suffer with PMS compared to women with the highest intake.
“The level of iron intake at which we saw a lower risk of PMS, roughly greater than 20 mg per day, is higher than the current recommended daily allowance (RDA) for iron for pre menopausal women,” Bertone-Johnson says.
The researchers also suggested that iron may be related to PMS because it is involved in producing serotonin, a neurotransmitter that helps to regulate mood.
While iron supplements may of course be helpful to ensure adequate intake, it’s important to ensure that good dietary sources of iron are included each day. Good plant-based sources of iron include pulses such as lentils, beans and chickpeas, nuts and seeds, dried apricots and leafy greens such as spinach and kale. Iron-fortified cereals are another rich source. Adding citrus fruit or a glass of orange juice is also helpful as Vitamin C boosts iron absorption.
Another mineral was also highlighted by the study as significant in its influence on PMS. “We also saw some indication that high intake of zinc was associated with lower risk” Bertone-Johnson explains. The level of zinc linked to a lower risk of PMS was greater than 15mg each day which again is higher than the RDA.
Zinc is needed for the proper action of many hormones and it can also lower levels of hormones such as prolactin which are implicated in PMS.
Ensuring a good intake of zinc through the diet means eating zinc-rich meats such as venison, beef and turkey, while vegetarians should emphasise foods such as yoghurt, spinach, mushrooms and oats. Zinc from plant sources is less well-absorbed and so vegetarians may benefit from a zinc supplement to ensure adequate intake. It should be noted, however, that excessive levels of zinc can be detrimental to health and should only be taken under the supervision of a health practitioner.
More research is needed in this area to confirm the results of this study. In the meantime, however, ensuring an adequate intake of both iron and zinc seems a sensible measure for those who suffer with PMS.
1. Patricia O. Chocano-Bedoya, JoAnn E. Manson, Susan E. Hankinson, Susan R. Johnson, Lisa Chasan-Taber, Alayne G. Ronnenberg, Carol Bigelow, and Elizabeth R. Bertone-Johnson. Intake of Selected Minerals and Risk of Premenstrual Syndrome. American Journal of Epidemiology, 2013 DOI: 10.1093/aje/kws363.
2.Image courtesy of topfer.