NMU 324 – Indole-3-carbinol in Cancer Prevention

Nutrition/Natural Medicine Update No 324 (June 4, 2024)

with Dr. James Meschino

Topic: Indole-3-carbinol in Cancer Prevention

Source: Frontiers of Nutrition Journal (October 1, 2021)

Many population studies (epidemiological studies) show that higher intake of cruciferous vegetables is strongly tied to a reduced risk of some important cancers, including breast, prostate cancer. Cruciferous vegetables include, broccoli, brussels sprouts, cabbage, cauliflower, Bok choy, kale, turnips, collard greens, kohlrabi, horseradish, land cress, rapini, watercress, mustard seeds, radish, wasabi and a few others. This family of vegetables contain a unique phytonutrient known as the indole-3-carbinol, which shows impressive anti-cancer properties in many experimental studies. Cruciferous vegetables also contain another unique compound known as sulforaphane (derived from hydrolysis of glucoraphanin), which is also shown to provide additional health benefits. So, I would encourage you to try to consume one or more cruciferous vegetables every day, if possible.

In October of 2021, the journal, Frontiers of Nutrition, published a comprehensive review of the anticancer research related to the administration of indole-3-carbinol, which is derived from cruciferous vegetables. As they explain, cruciferous vegetables contain glucobrassicin that gets converted into indole-3-carbinol, which in turn gets converted into DIM (3,3-diindolymethane). Both indole 3-carbinol and its metabolic product DIM, show impressive anticancer properties in a variety of experimental and animal research studies. With respect to human clinical trials related to reducing breast cancer risk, the administration of indole-3-carbinol to women is shown to convert more estrogen into the safer form of estrogen known as 2-hydroxy estrone, helping to reduce the synthesis of the more cancer-promoting form of estrone, known as 16-hydroxy estrone, which is tied to higher risk of breast and uterine cancer. As they state, “the ratio of 2-hydroxy to 16-hydroxy estrone has become a biomarker for risk of estrogen-dependent cancer and cervical intraepithelial neoplasia (CIN)”, which can progress to cervical cancer. Supplementation with both indole-3-carbinol and DIM has been shown to increase the 2:16 hydroxy estrone ratio improving outcomes for women diagnosed with cervical intraepithelial neoplasia (CIN). As well, supplementation with indole-3-carbinol or DIM in these human studies is shown to be very safe.Many experimental studies have shown the indole-3-carbinol also inhibits key pathways in the development of prostate cancer.

And human studies show a significant slowing of prostate cancer progression when men with existing prostate cancer are provided with a DIM supplement (derived from indole-3-carbinol). These men also showed a decrease in androgen (testosterone) receptors, including on the nucleus of the cell. This effect helps to prevent testosterone from stimulating the growth and replication of prostate cancer cells.  Once again, high dose supplementation, in the range of 200-400 mg per day did not produce any adverse health effects, making it a very safe supplement to take.

In their concluding remarks the researchers point out that to match the indole-3-carbinol intake used in preclinical and clinical studies, it is not possible to acquire sufficient indole-3-carbinol or DIM from simply eating cruciferous vegetables. Rather, supplementation with pure indole-3-carbinol and/or DIM is the only way to match these intake levels. Certainly, eating cruciferous vegetables is very helpful for basic prevention, but in my view, once you are over 50 years of age, when cancer risk escalates at an alarming rate, I would suggest that you do what I do:

Ingest one or more cruciferous vegetables every day if possible.

And take a supplement each day that contains an additional 30-60 mg of indole-carbinol. The supplement I take also contains Astragalus, Reishi mushroom extract, and Milk Thistle. This combination of nutrients helps to support immune function (very important in cancer prevention) and have various properties shown to block steps in the development of many types of cancer.

I have included the reference for indole-3-carbinol and DIM in the text below.

Reference:

Williams D.E. Indoles derived from glucobrassicin: Cancer chemoprevention by indole-3-carbinol and 3,3-diindolymethane. Frontiers of Nutrion. 2021, 8: 734334. Indoles Derived From Glucobrassicin: Cancer Chemoprevention by Indole-3-Carbinol and 3,3′-Diindolylmethane – PMC (nih.gov)

Eat Smart, Live Well, Look Great,
Dr. Meschino