by Ronald Hoffman, MD
Every now and then, I like to highlight a particular supplement that my audience may not be aware of, and go in-depth about its uses, benefits, and potential drawbacks.
This week, I’d like to talk to you about DIM.
Diindolylmethane (DIM) is a versatile nutraceutical for which I find many uses in my practice. It is naturally obtained via dietary consumption of cruciferous vegetables. Brussel Sprouts, Garden Cress, Mustard Greens, Turnip, and Kale are rich sources of glucobrassicans, the mother compounds of beneficial glucosinolates like indole-3-carbinol, which is metabolized into DIM. However, heat treatment, particularly boiling and microwaving, degrades myrosinase, the plant compound responsible for bio-transformation of glucobrassicans into useful molecules like DIM and sulforaphane.
An advantage of supplementation with DIM over consumption of large amounts of raw cruciferous vegetables is avoidance of goitrogenic isothiocyanates. These compounds compete with iodine for binding in the thyroid, potentially contributing to hypothyroidism. DIM is thought not to have goitrogenic properties. To obtain the benefits of DIM contained in just two capsules per day, it is estimated that the average person would have to consume two pounds of raw cabbage family vegetables per day, an intake that might court the danger of thyroid suppression.
DIM possesses hormone-modulating effects. It may do so in several ways. Studies suggest it protects the body from xenoestrogens, compounds that mimic and intensify the effects of estrogen. DIM has also been shown to favorably alter the ratios of “good” to “bad” estrogen. In the prostate, DIM has been found to antagonize the effects of dihydrotestosterone (DHT), an excess of which is associated with risk of enlarged prostate and prostate cancer.
Thus, DIM’s application to hormone-dependent cancers (breast and uterine in women, prostate in men), as well as to the condition of “estrogen dominance”, wherein high estrogen levels promote symptoms like breast pain, fibrocystic breasts, uterine fibroids, endometriosis, PMS, bloating, anxiety, fat accumulation, and heavy menstruation.
Because DIM combats excess estrogen in females, it might help as a diet aid for women who struggle with a pear-shaped fat distribution.
Another theoretical benefit of DIM may be to offset the potential risks of hormone-dependent cancers in patients taking hormone replacement therapy with estrogen or testosterone.