Estrogen is the term used to describe a group of essential steroid sex hormones present in both men and women. Although estrogen has no known functions in men, it is essential for women. Estrogen promotes the development of the female sexual organs and supports a healthy reproductive system. It is important to keep estrogen levels balanced. Cruciferous vegetables, especially broccoli, contain many nutrients that promote healthy metabolism of hormones, thereby reducing the negative side effects associated with excess estrogen.

Estrogen Imbalances

Estrogen levels in men and women can become undesirably high due to obesity, stress and exposure to xenoestrogens, which are substances like pesticides, heated plastic and commercially raised animal products. These xenoestrogens mimic naturally occurring estrogen in the body, causing negative side effects. In men, high estrogen may lead to a decrease in sex drive, decreased muscle mass, chronic fatigue and an increased risk of developing prostate cancer. Women may experience severe premenstrual syndrome, unexplained weight gain, hot flashes, allergies, osteoporosis and depression.

Calcium to Reduce Premenstrual Syndrome

One of the major symptoms women experience due to estrogen imbalance is premenstrual syndrome. According to a 10-year study published in June 2005 in "JAMA Internal Medicine, high calcium intake reduced the severity of premenstrual syndrome in women ages 25 to 42 4. Two cups of cooked broccoli contain about 20 percent of the daily recommended value of calcium for women.

Indoles for Cancer Prevention

Broccoli contains phytochemicals called indoles, which play a role in estrogen metabolism. Indoles convert excess estrogen into a safer form, which significantly reduces the risk of estrogen-linked cancers, such as breast cancer and prostate cancer. A study involving 96 women published in "Breast Cancer: Basic and Clinical Research" in April 2010 concluded that there was a strong correlation between indoles and breast cancer prevention. Treatment with these indoles increased the concentration of estrogen byproducts in urine, which indicates that estrogen was being metabolized safely and more efficiently.

Fiber for Estrogen Metabolism

A study published in September 1991 in "The American Journal of Clinical Nutrition" showed a negative correlation between fiber and serum estrogen 1. In the study, women were asked to double their fiber intake, and after two months, all participants had significantly lower levels of circulating estrogen in their blood. A reduction in circulating estrogen reduces the risk of many hormone-related cancers and improves the symptoms associated with excess estrogen. Two cups of cooked broccoli contains 30 percent of the daily recommended intake of fiber.