Menstrual Pain and Diet

Neal D. Barnard, M.D.

Disorders of menstrual function can be taxing and sometimes even disabling. Up to 10 percent of women in their teens and early twenties suffer from severe menstrual pain. In most cases, there is no identifiable cause. However, for some women, the pain is a symptom of endometriosis (a condition in which cells that normally line the uterus have ended up in the abdominal cavity), adenomyosis (the existence of islands of uterine lining cells deep within the uterine muscle), fibroids (the presence of overgrown muscle cells in the wall of the uterus), or other conditions. Nutritional factors appear to play an important role in managing menstrual pain.

Premenstrual syndrome includes feelings of moodiness, tension, or irritability, as well as physical symptoms, such as water retention. Like menstrual pain, it appears to be influenced by nutrition.

One of the treatments we are testing is the use of a very-low-fat, vegetarian diet. We are using this diet because, when it is properly followed, it has the very helpful effect of reducing the amount of estrogen in the blood, sometimes to a striking degree. For some individuals at least, diets that avoid animal products and keep vegetable oils to a bare minimum cause a marked reduction in menstrual pain, presumably because of the diet’s effect on hormones.

There are several reasons why this diet affects hormones. First of all, reducing the amount of fat in the food you eat reduces the amount of estrogen in your blood. This appears to be true for all fats—animal fats and vegetable oils.

Second, plant products contain fiber (roughage), which tends to carry estrogens out of the body. Here is how it works: The liver filters estrogens out of the blood and sends them down a small tube, called the bile duct, into the digestive tract. There, fiber from grains, beans, vegetables, and fruits soaks up the estrogens like a sponge. If plant foods are a major part of your diet, you’ll have plenty of fiber. But the amount of fiber in your diet is reduced when you have yogurt, chicken breast, eggs, or other animal products, because fiber comes only from plants. Without adequate fiber, the estrogens in your digestive tract end up being reabsorbed back into the bloodstream.

Certain foods that are common in vegetarian diets have special effects. Soy products, for example, contain phytoestrogens, which are very weak plant estrogens that reduce your natural estrogens’ ability to attach to your cells. The result is less estrogen stimulation of cells.

In addition to individual reports that low-fat, vegetarian diets can cause dramatic reductions in menstrual pain, vegetarians also have fewer ovulatory disturbances. Some researchers have found that excess estrogen plays a role in PMS symptoms, too, and that shifting the balance of the diet away from fatty foods and toward high-fiber plant foods is helpful.

- Source: Physicians Centre For Responsible Medicine