Diindolylmethane (DIM) is a natural condensation product of indole-3-carbinol (I3C), which is found in cruciferous (Brassica family) vegetables such as cauliflower, cabbage, cress, bok choy, broccoli, kale, and similar green leaf vegetables. Increased dietary intake of these foods has been associated with a lowered risk of unhealthy cell growth, particularly those with a hormonal influence on proliferation.
Part of this effect is likely due to DIM's role in estrogen metabolism balance in the body. There is also preliminary research implicating DIM as an immunomodulating supplement against auto-immune disease, although further research is required.
Understanding The Relationship Between DIM and I3C
DIM is a natural diindole condensation product of I3C created during digestion in the presence of sufficient stomach acid. This chemical is more shelf-stable and more easily absorbed in the digestive tract than I3C. Recent research has implied that benefits previously attributed to I3C may be the result of DIM created through conversion in the digestive tract. Further research is required to confirm these results before attributing all of the beneficial effects of I3C to DIM.
Key Health Benefits of DIM
DIM and Unhealthy Cell Growth
Diindolylmethane has been associated with potent effects on unhealthy cell growth. Emerging evidence has shown that exposure of damaged human cells to I3C or DIM triggers transcriptional, cell signalling, enzymatic, and metabolic changes that directly lead to the stoppage of replication and/or apoptosis (regulated cell death). It has also been implicated in down-regulating genes required for damaged cells in the breast, although I3C has been studied in far greater detail for this activity.
DIM and Estrogen Balance
Both males and females produce estrogen naturally in their bodies, although women produce significantly higher levels. This endogenous estrogen can either be metabolized to 16alpha-hydroxyestrone (16OHE1) or 2-hydroxyestrone (2OHE1). In contrast to 2OHE1, 16OHE1 is highly estrogenic and has been found to stimulate the proliferation of several estrogen-sensitive damaged cell lines. Research suggests that DIM preferentially promotes the metabolism of estrogen to the less harmful, and less active 2-hydroxyestrone form.
Diindolylmethane and Male Hormone Health
DIM has been directly studied as an anti-androgen supplement that can prevent the proliferation of damaged prostate cells. It has also been found to reduce PSA expression and act as a strong competitive inhibitor of dihydrotestosterone (DHT), a hormone responsible for many male-associated problems. DIM is likely the first example of a pure androgen receptor blocker extracted from plants.
Diindolylmethane and Age-Related Muscle Loss in Men
As men age, they naturally produce lowered levels of testosterone and over time estrogen can be found in higher concentrations in their tissues, resulting in a loss of muscle mass. Testosterone is one of the hormones responsible for anabolic muscle growth in the body. There is a natural balance of the conversion of testosterone to estrogen in the body. As noted above, DIM has been shown to regulate the metabolism of estrogen in the body to be less active. This helps to shift the hormonal balance more favourably in men entering andropause ("male menopause").
Taking DIM Supplements
Diindolylmethane can be absorbed directly from eating cruciferous vegetables from the Brassica family, such as cauliflower, cabbage, cress, bok choy, broccoli, kale, and similar green leaf vegetables. It is important that if cooking these vegetables, not to boil them, as it will significantly reduce their beneficial content.
To get higher doses, DIM can be supplemented using capsules or combination formulas. When supplementing DIM, it is generally taken between 100 and 200 mg per day. A dose of 200 mg was found by a preliminary safety study to be the highest dose that did not produce negative side effects in the research group.
Final Insights, Considerations & Potential Side Effects
DIM is considered safe in both food/diet amounts and therapeutic dosages. Excess supplementation may result in skin rashes, increased liver enzymes, as well as nausea and vomiting. Overuse and/or preventative use of DIM is further ill-advised because of its hormone-altering effects in normal individuals that can result in systemic hormone dysregulation. For this reason, do not use it as a supplement while pregnant or breastfeeding.
