A new US study says that women who eat a diet rich in iron may be 30 to 40 percent less likely to develop pre-menstrual syndrome than women who consume lesser amounts.
In the observational study, about 3,000 women completed three food frequency questionnaires over the 10-year study period (1). After 10 years, 1,057 women were diagnosed with premenstrual syndrome (PMS) and 1,968 remained free from PMS. The study results showed that women who consumed the most non-heme (the form found primarily in plant foods and in supplements) iron (greater than 20 mg per day) had a 30 to 40 percent lower risk of developing PMS than women who consumed the least amount of non-heme iron, after adjusting for calcium intake and other potential PMS-related factors. In addition, the results indicated that high intake of zinc (greater than 15 mg per day) was associated with lower risk of PMS while women consuming the highest amount of potassium had a higher risk of being diagnosed with PMS. Intake of other minerals, including magnesium, copper, sodium and manganese were not associated with PMS risk. In general, results for minerals and trace elements from food sources and from supplements were similar.
The researchers concluded that women at risk for PMS should make sure they are meeting the recommen-ded intakes for non-heme iron and zinc. As high iron and zinc intake may have adverse health consequen-ces, women should avoid consuming more than the tolerable upper intake level of 45 mg iron and 40 mg zinc per day unless otherwise recommended by a physician. Iron may be related to PMS, because it is involved in producing serotonin, a neurotransmitter that helps to regulate mood. The unexpected finding of higher PMS risk with high potassium intake may be related to potassium’s role in regulating fluid balance in the body. It may affect PMS symptoms such as swelling in the extremities and bloating by affecting fluid retention. The findings would need to be replicated in further studies, the scientists noted.