When I heard myself use the expression, “I just want to kill everything and then eat it dipped in chocolate” yesterday, I figured it was time for another post on foods you should eat before and during your period.

I’ve talked about some of the basics of what to eat and on the importance of iron during menstruation, but another important nutrient is calcium.

Cramps in the lower abdomen and lower back are caused by contractions of the uterus, which is a muscle. Though the uterus contracts and relaxes throughout your cycle, in the days leading up to menstruation, increased production of prostaglandins (chemicals made by the uterine lining) trigger stronger contractions. During menstruation, prostaglandin levels decrease, which is why cramps tend to subside a few days into your period.

In studies involving both dietary sources and supplements, calcium has been shown to reduce pain associated with cramps, as it plays a key role in muscle function by carrying messages between cells about what needs to happen and where.

Calcium has also been shown to reduce breast tenderness and swelling due to its action on prostaglandin production. It has also been shown to provide some relief from behavioral PMS symptoms. Because estrogen regulates calcium absorption, changes, menstrual fluctuations impact calcium levels. Low levels of calcium, like PMS, can be characterized by mood swings, anxiety, and depression, so maintaining steady calcium levels may also help keep you from wanting to kill everything and eat it dipped in chocolate.

Good sources of calcium include:

  • Yogurt
  • Milk (dairy and fortified non-dairy milk)
  • Cheese
  • Cottage cheese
  • Dark, leafy greens like kale
  • Broccoli
  • Bok Choy
  • Tofu
Ladies, what are some of your go-to calcium-rich foods? 
References:
Penland JG, Johnson PE. Dietary calcium and manganese effects on menstrual cycle symptoms. Am J Obstet Gynecol. 1993;168:1417-1423.
Storck, S and Zieve, D. Breast: Premenstrual tenderness and swelling. Medline Plus. http://www.nlm.nih.gov/medlineplus/ency/article/003153.htm. Accessed july 9, 2011)
Thomson, C. “Intervention: Dietary Supplementation and Integrative Care” in           in Krause’s Food & Nutrition Therapy 12th Edition. Mahon, L and Stump, S eds. Saunders Elsevier. St. Luis. 2008. 470-488.
Thys-Jacobs S. Micronutrients and the premenstrual syndrome: the case for calcium. J Am Coll Nutr. 2000;19:220-227.
Thys-Jacobs S, Starkey P, Bernstein D, Tian J; Premenstrual Syndrome Study Group. Calcium carbonate and the premenstrual syndrome: effects on premenstrual and menstrual symptoms. Am J Obstet Gynecol. 1998;179:444-452.