Studies have shown a correlation between eating large amounts of cruciferous vegetables like broccoli and a lower risk of cancer. And, more to the point, researchers may have finally found one of the reasons why. Cruciferous vegetables contain an enzyme that breaks down into a unique compound in the body. This compound, I3C, activates a tumor-suppressing enzyme, and tests on supplemented mice have shown it can significantly reduce cancer risks. More research is needed, now that they've had this breakthrough. Because in some cases high doses of I3C may actually increase cancer risks—so it’s best not to start supplementing until more is known. But eating whole foods, broccoli and other cruciferous included, is definitely recommended—especially with this news. Let's break down what we know.
Researchers have documented numerous reports of those who eat large amounts of broccoli and other cruciferous vegetables having lowered cancer risks. Now, they may have pinned down one reason why. In many cancers, including tumors of the breast, prostate and liver, there may be overexpression of the gene WWP1. This gene suppresses the activity of a tumor-suppressing enzyme, PTEN, opening the doors for uncontrolled tumor growth.
Cruciferous vegetables, such as broccoli, Brussels sprouts, cabbage, cauliflower and kale, contain an enzyme that breaks down into compounds with unique properties. One of these compounds, indole-3-carbinol (I3C), has activated PTEN in mouse models. Researchers have long dreamed of finding a compound like this one—capable of harnessing the body’s own natural defense system to fight tumors. According to the study’s researchers, finding the key to unlock PTEN may be akin to discovering cancer’s “Achilles heel.”
I3C also affects the body’s ability to synthesize estrogen, making the hormone less available to estrogen-dependent tumors. This could prove to be an especially effective weapon against certain types of breast, endometrial, ovarian and colorectal cancers. Some researchers also speculate even broader applications for I3C, such as a treatment for other conditions estrogen may also exacerbate, like systemic lupus erythematosus.
I3C may have some amazing properties, but therapeutic doses may not be easy to meet. The precursors found in broccoli and other cruciferous vegetables break down quickly when exposed to heat, so you need to eat them raw and in massive servings for any notable benefit. And supplements might not be the answer.
Studies have shown indole-3-carbinol supplements may not raise I3C levels in the blood, although they do seem to elevate a similar compound called DIM. In some cases, supplements even appeared to increase the chances of tumor growth. Researchers are currently looking into strategies to improve I3C supplement safety and efficacy.
For now, authorities caution against using I3C supplements, which are readily available through most retailers. I3C can cause stomach upset in some people, and high doses may lead to tremor and problems with equilibrium.
Cruciferous vegetables like broccoli may not be the simple cure researchers have been hoping for, but their properties are worth a closer look. Incorporate them as often as you can into your diet—not just for the potential anticancer properties but also for their rich sources of vitamins, antioxidants and fiber. You might be doing your future you a favor on multiple fronts.