Eat your Broccoli! - Doctor's orders

Posted by Chris Penton on

Our newest Market Muser, Dr. Colbran Marjerrison ND, tells us why broccoli could save your life! OK, maybe not save it, but it will certainly help you out along the way. The good doctor can be found at

“Eat your broccoli” your mom surely said to you more than once at the dinner table growing up. Not just an order for kids as we try to fill them up with greens, as a Naturopathic Doctor I often find myself giving this gentle advice to adults for the beneficial effects on their health concerns. Three major reasons I may recommend someone to increase their consumption of broccoli and other vegetables of the Brassica family include increasing estrogen metabolism, the preventive effect of brassica consumption against certain cancers, and support of metabolic processes of the liver.

The two major constituents in broccoli, indole-3-carbinole (I3C) and its metabolite diindolylmethane (DIM) are researched to have a profound impact on estrogen metabolism. These components are shown to shift estrogen metabolism away from stronger acting estrogen metabolites to those with weaker estrogenic activity. Multiple studies show positive effects of altered estrogen metabolites in the urine as a result of brassica vegetable consumption.

Quiz: In which health concerns would we be interested in promoting a shift away from strong acting estrogen metabolites?

A: Cases of estrogen dominance. (schools may have been closed since March but I know you got that right)

Estrogen dominance in women is associated with health concerns such as fibroids, endometriosis, fibrocystic breasts, estrogen dominant cancers, weight gain in thighs and mid-section. Each of these concerns have shown benefit from increasing consumption of brassica vegetables. Individuals of all genders may experience estrogen dominance as gynecomastia, low libido, fatigue and decreased exercise performance. Trans-men may be recommended to increase regular brassica consumption if one of their goals is to decrease signs of excess estrogen.

In addition to shifting estrogen metabolism to more favourable pathways, brassica vegetables may actually decrease conversion of testosterone to estrogen by inhibiting the enzyme aromatase. This action causes a reduction in the amount of estrogen produced in the body overall and may be a recommendation for individuals looking to increase mood, libido and possibly exercise tolerance.

Inhibition of aromatase is also where much of the research of beneficial effects of broccoli and brassica consumption originate in regard to prevention of hormone specific cancers (male and female). This action may be a contributing factor to why supplementing with I3C or DIM has shown a reduction in breast cancer cell proliferation and migration in some forms of breast cancer. Additionally, in vitro studies show I3C to inhibit growth of breast, prostate, colon and cervical cancer cells (ladies, yes that includes HPV infection and cervical dysplasia!). These observations are consistent with epidemiological evidence that associates a high dietary intake of brassica and cruciferous vegetables with a decreased risk of these cancers.

The final reason I’ll leave you with supporting why increasing brassica consumption may be recommended as a part of a naturopathic protocol, is that it helps to support both metabolic processes of the liver and the health of the organ overall. Brassica veggies have a high sulphur content, which is required by liver cells to support the second phase of liver detoxification.  Sulphoraphane, a sulphur containing phytochemical in broccoli, has been specifically researched for ability to improve liver function in cases of fatty liver disease by enhancing phase II detoxification and reducing oxidative stress.

Quiz: How much broccoli does a person have to eat to get the benefits? I’ll give you a hint – no, it’s not all the broccoli, all the time, only eating broccoli.

A: 1 cup of chopped broccoli per day or other cruciferous vegetable (measured raw) will absolutely get you off to a great start. Each cup of broccoli contains about 100mg of sulforaphane and I3C which in combination with a healthy lifestyle is adequate for maintenance of good health. Your Naturopathic Doctor will be able to help you out and let you know if it is a good idea for you to kick it up from there or consider supplementation.

Cooking tip:  

About 20% of I3C is lost when you boil your Brassica veggies for 10 mins. I always recommend cooking to the point when the vegetable is its brightest colour – this usually only takes ~3-4 minutes on simmer, covered. Cooking to that bright spot minimizes loss of nutrients to the cooking process and ensures your digestive tract is supported in the absorption of them.  

Please do not hesitate to contact me if you have questions!  I love to hear from the community and talk about Naturopathy, it is always a pleasure. I am also happy to send scientific reference articles if that is of interest to you.


The topics outlined in this article are not medical advice. As naturopathic recommendations are specific for your unique health concerns, there is great variability in what may be recommended for you and why in terms of dietary interventions and nutritional supplementation. While the research in hormonal support, hepatic support and preventative/adjunctive cancer care are fascinating, please consult your naturopathic doctor before self-prescribing. Topics outlined in any case are never a substitute for medications you may be prescribed. 

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