Principal Proposed Uses
Other Proposed Uses
Diindolylmethane (DIM) is produced when the substance indole-3-carbinol (I3C) is digested. Indole-3-carbinol, found in broccoli and other vegetables, has shown considerable promise for cancer prevention . Some of its benefits in this regard may occur after it is converted by the body to DIM. DIM also has complex interactions with the hormone estrogen, which could lead to either positive or negative effects on cancer risk.
There is no dietary requirement for DIM. Good natural sources include broccoli, Brussels sprouts, cabbage, and cauliflower.
Manufacturers selling DIM products typically recommend about 500 to 1,000 mg daily. The optimal dose (if there is any) is not known.
Therapeutic Uses Numerous test-tube and animal studies hint that DIM is might help prevent various types of cancer, especially breast, cervical, prostate, and uterine cancer. 1-16 However, this evidence is far too preliminary to serve as the basis for recommending that anyone use DIM. As with many proposed cancer-preventing substances, there are also circumstances in which DIM might actually increase the risk of cancer. 17-19 Some of DIM’s apparent anticancer benefits appear to derive from its complex interactions with estrogen. 20-27
DIM appears to alter liver function in such a manner that an increased amount of estrogen becomes metabolized into inactive forms. In addition, DIN blocks certain effects of estrogen on cells; however, it may enhance other effects of estrogen. The overall effect is far too complex and poorly understood to be described as “balancing estrogen in the body,” which is what many websites say about DIM. DIM also appears to have an anti-testosterone effect, which could make it helpful for preventing or treating breast cancer. 28 Again, on some websites this effect has been over-optimistically termed “balancing testosterone levels.” Highly preliminary evidence hints that DIM may offer benefit for diseases caused by human papilloma virus (HPV). These include cervical dysplasia and respiratory papillomatosis. 29,30
According to some manufacturers, DIM can enhance sexual function
in men or women
, and also enhance sports performance
. However, there is no evidence that it actually works.