What Is It?
Diindolylmethane (DIM) is a plant compound derived from digesting indole-3-carbinol, which is found in Cruciferous vegetables such as broccoli, Brussels sprouts, cabbage and cauliflower. It promotes beneficial estrogen metabolism in women and men, thereby working to balance Hormone levels. It also detoxifies the intestines and liver and supports a healthy immune system. Researchers believe indole-3-carbinol, and thus DIM, also might be one of the cancer-protective agents found in the cruciferous vegetables.
Indole-3-carbinol is produced when the vegetables are cut or chewed but is inactive until it comes into contact with stomach acid, causing it to be converted to the active metabolite DIM. Researchers are interested in this for potential cancer-protective properties against breast, cervical, endometrial, and colorectal cancers. For this reason, the National Cancer Institute has reviewed the use of DIM for preventing several forms of cancer and is now sponsoring clinical research for breast cancer prevention. Diindolylmethane also is being researched as a potential treatment for a variety of viral infections and anti-biotic resistant bacteria
Diindolylmethane seems to have several effects on estrogen and the metabolism of toxins in the liver. Because it induces a compound that alters estrogen metabolism, DIM may be helpful in protecting against hormone-dependent cancers such as breast cancer. Some evidence also suggests DIM may have other protective effects as an Antioxidant. It is used to treat fibromyalgia, laryngeal papillomatosis, cervical dysplasia, premenstrual syndrome (PMS) and systemic lupus erythematosus, as well as to balance hormone levels, detoxify the intestines and liver, and to support the immune system.
Specifically, DIM may help:
- Prevent breast cancer and cervical cancer. Ingestion of indole-3-carbinol, and thus the production of DIM, alters estrogen metabolism of estradiol, a sex hormone that has a critical impact on reproductive and sexual functioning. Estradiol normally is metabolized into compounds that are thought to increase the risk of breast and cervical cancers. However, the DIM causes estradiol to be metabolized to a weaker estrogen and more benign compound, possibly producing a protective effect against these hormone-related cancers. Several in vitro studies and studies on rodents have found potential activity against breast cancer cells by inhibiting tumor growth and inducing apoptosis (programmed cell death) in human breast cancer. However, conflicting evidence exists, and more research is needed to confirm the role of DIM in preventing cancers in humans.
- Cervical dysplasia. In patients with mild (or early precancerous stages of) cervical dysplasia (CIN), synthetic and natural forms of indol-3-carbinol have been shown to prevent further development of the invasive disease of the cervix. In a 2000 Placebo-controlled study of 30 women with stage II-III CIN, treatment of 200 mg or 400 mg of indole-3-carbinol daily for 12 weeks seemed to cause complete regression of CIN. The lower dose seemed to be just as effective as the higher dose.
- Respiratory papillomatosis. Some preliminary clinical evidence indicates that long-term use of indole-3-carbinol might reduce papilloma growth in patients with recurrent respiratory papillomatosis. In a 2000 placebo-controlled study of 18 patients treated with oral indole-3-carbinol for eight months or longer, six patients (33 percent) reported cessation of papilloma growth and did not require surgery, another six patients reported a reduced growth rate, and the remaining six patients showed no clinical response to the compound. Researchers concluded that indole-3-carbinol appears to be safe and well tolerated and may be an efficacious treatment for recurrent respiratory papillomatosis. However, a blind, controlled trial was recommended. A 2007 review of studies found that small preliminary trials in humans suggest supplementation may be beneficial in treating conditions related to human papilloma virus infection, such as recurrent respiratory papillomatosis, but larger randomized controlled trials are needed.
The typical diet supplies 20 to 120 mg of indole-3-carbinol per day (one head of cabbage contains about 1200 mg). About 10 to 20 percent of the typical intake of indole-3-carbinol is converted to diindolylmethane, providing 2 to 24 mg daily.
Current evidence does not support recommendations for dosages for DIM at this time. DIM in a patented oral delivery system (U.S. patent #6,086,915) is available in 75 to 150 mgm capsules containing @ 25% DIM .
Guidelines for Use
Diindolylmethane is not easily absorbed. Taking some forms of Vitamin E enhances the absorption of DIM. The patented form of DIM is being used in the current clinical trials. Consult your doctor or licensed nutritional counselor before taking supplements containing these nutrients.
There are no known drug or nutrient interactions associated with DIM.
Possible Side Effects
There are no known side effects associated with DIM.
If you are pregnant or lactating, the amount of DIM typically consumed in foods is likely to be safe. However, insufficient evidence exists regarding amounts greater than those found in foods, so you should avoid consuming more DIM than what you get from your normal diet during pregnancy and breastfeeding.
David Edelberg, MD