Is Indole-3-Carbinol also good for Testosterone?

Indole-3-Carbinol or in short I3C is a compound well known for a wide-range of health applications such as anti-inflammatory and anti-atherogenic, supporting antioxidant enzymes and boosting the immune system. More recently, it was discovered that I3C modulates the expression and activity of enzymes involved in the regulation of hormones. It's most prominent bio-activity is to alter the metabolism of estrogen, which in turn impacts testosterone levels.

How I3C works on testosterone levels

It was previously believed that only women can develop problems with estrogen levels. The truth is that men may also have problems with excess estrogen and reduced levels of testosterone with negative impact on prostate and sexual health. Although indole-3-carbinol does not directly elevate testosterone levels, studies have shown that I3C may indirectly influence testosterone via anti-estrogenic pathways <1>:
  • Inhibits synthesis of estrogen,
  • Promotes metabolization of estrogen and increase the ratio of 2-hydroxyestrone (“good” estrogen metabolite) to 16alpha-hydroxy Estrone (“bad” estrogen metabolite),
  • Blocks estrogen signaling.
The result of these pathways is the release of testosterone bound to sex-hormone binding globulin (SHBG), which enables testosterone to cross the blood-brain barrier and produce its effects throughout the body.

Indole-3-carbinol is useful for both men and women

Downregulation of aromatase in men

I3C and its constituent DIM, down-regulate the expression of aromatase, or CYP19, which is the protein responsible for converting testosterone into estrogen <2>. Decreasing the presence of aromatase can limit the amount of testosterone that is replaced by estrogen. This is beneficial for both women and men, and very important for older men with low testosterone levels due to ageing. Older men's lower testosterone to estrogen ratio can result in health problems such as gynecomastia, loss of muscle tissue, fat accumulation, alopecia, enlarged prostate, loss of libido, and erectile dysfunction. I3C might be able to counteract this by restricting estrogen <3>.

Reduction of excess estrogen in women

In women, during pre-menopause and menopause but more recently even in young women, excess estrogen increases the risk of breast cancer. Recently, researchers have discovered that there is also a connection between aromatase and obesity <4>, <5>, <6>. In conclusion, Indole-3-carbinol is useful for both men and women. Provita offers 2 highly efficient products containing Indole-3-Carbinol and DIM: References:
  1. Liu H, et al. Indolo(3,2-b)carbazole: a dietary-derived factor that exhibits both antiestrogenic and estrogenic activity. Journal of the National Cancer Institute. 7 Dec 1994;86(23):1758-65
  2. Licznerska BE, et al. Modulation of CYP19 expression by cabbage juices and their active components: indole-3-carbinol and 3,3′-diindolylmethene in human breast epithelial cell lines. Eur J Nutr. 2013 Aug;52(5):1483-92
  3. Chang YC, et al. Cytostatic and antiestrogenic effects of 2-(indol-3-ylmethyl)-3,3′-diindolylmethane, a major in vivo product of dietary indole-3-carbinol. Biochem Pharmacol. 1999 Sep 1;58(5):825-34
  4. Serdar E. Bulun, et al. Aromatase, breast cancer and obesity: a complex interaction. Trends Endocrinol Metab. 2012 Feb; 23(2): 83–89
  5. Jie Chen et al. The correlation of aromatase activity and obesity in women with or without polycystic ovary syndrome. Journal of Ovarian Research volume 8, Article number: 11 (2015)
  6. Xuyi Wang et al. Aromatase overexpression in dysfunctional adipose tissue links obesity to postmenopausal breast cancer. J Steroid Biochem Mol Biol 2015 Sep;153:35-44.