DIM: Cancer-Fighting Supplement Doesn’t Work (Try These Foods Instead)
Mom was right when she urged you to eat your broccoli.
Sure, we already knew that this vegetable is a nutritional powerhouse that should have a place on everyone’s plate. It’s rich in vitamins A, C, K, and many B vitamins – just to name a few nutrients.
But broccoli also contains another compound that appears to show promise in protecting against certain cancers, specifically those that involve the hormone estrogen.
Even more exciting, this substance is also available in supplement form. So, if you’re like former President George Bush – and countless kindergartners – and just can’t stand the thought of broccoli, this could be a great alternative.
Or could it?
See, there’s more to this compound than meets the eye. And it may not all be beneficial.
Cancer Protection in a Pill?
Diindolylmethane (DIM) is a compound commonly found in broccoli and other cruciferous vegetables such as cabbage, cauliflower, Brussels sprouts, and other members of the Brassica family.
We’ve always known that these types of veggies are healthy, but it wasn’t until about 20 years ago that scientists began to fully uncover their potential cancer-fighting properties. Researchers discovered that lab animals who consumed broccoli as part of their diet had a lower risk of some forms of cancer.
And when investigators later swapped out real broccoli with supplements of DIM, they found that this compound alone had beneficial anti-cancer effects.
DIM seems to help protect against cancer in a couple of ways. First, it may activate the body’s immune response. That means DIM could potentially have the ability to fight viruses including the human papilloma virus (HPV), which is a precursor to cervical cancer.
But the compound also appears to influence our hormone levels, estrogen in particular. See, DIM seems to increase the body’s efficiency in metabolizing estrogen. In other words, it may increase or decrease the amount of this hormone in the body.1,2,3
It’s this process that has intrigued researchers – and has led manufacturers to suggest that DIM supplements could prevent cancer.
However, the truth isn’t so clear-cut.
In fact, some research does show that DIM blocks the effects of estrogen.1,2,3 That’s great news if you’re hoping to guard against hormonally driven cancers, like breast, ovarian, cervical, and prostate cancer.
On the other hand, some studies show that DIM may also increase the effects of estrogen.1,2,3 And if you’re worried about hormonally driven cancers or already have a history of them – well, that could be bad news.
Let’s take a closer look at the research.
No Easy Answer…
In the lab, DIM has been shown to inhibit the growth of breast and prostate cancer cells. But that doesn’t mean that those results translate in humans.
Indeed, despite a fair amount of laboratory and animal research, good clinical trials of DIM in people are still pretty limited.
For instance, one small study of 19 older women with a history of early-stage breast cancer, published in 2004, found that taking DIM supplements appeared to alter estrogen levels. That suggests that the compound could potentially protect against breast and other hormonally driven cancers.6
And a 2008 study of 64 women with abnormal cervical cells (which are typically caused by HPV) showed that those who took supplemental DIM had a clinically significant improvement in these lesions after six months – but so did women who took a placebo.5
Other research has had disappointing findings. One study, published in 2012 in the British Journal of Cancer looked at the effects of DIM supplements in 551 women with newly diagnosed abnormalities in their cervical cells. After six months, researchers found no significant beneficial effect of DIM on cervical cells or HPV infection, compared to a placebo pill.4
That’s a far cry from demonstrating that these supplements can prevent cancer.
Eat Your Greens…
Although proponents of DIM supplements claim that these products can help “balance” estrogen, it’s clear that the mechanism is much more complicated than that.
The fact is, we don’t yet know if DIM supplements can actually help protect against hormonally driven cancers or not – or if the supplements could actually increase the risk of cancer in some people.
Effectiveness aside, we also don’t yet fully understand if DIM supplements are safe or at what dose they should be taken. Manufacturers typically recommend taking 500 mg to 1,000 mg a day, but it’s not clear if this is indeed an optimal dose. At least one study found that people who took DIM experienced nausea and vomiting at just 300 mg daily.
Other side effects may include confusion, dizziness, and an increased risk of bleeding. For this reason, you certainly shouldn’t take DIM supplements if you also take anticoagulant drugs such as warfarin (Coumadin).
And because it appears that DIM may have varying effects on estrogen, it’s a good idea to pass on this supplement if you have a hormone-sensitive condition, including breast, ovarian, cervical, or prostate cancer, uterine fibroids, and endometriosis.
Don’t get me wrong: DIM could turn out to be the next big supplement. But the truth is, we just don’t know enough about it for me to wholeheartedly recommend it at this stage – especially when it could come with some troubling risks.
What you can do now is include plenty of Brassica vegetables in your diet. The typical diet supplies between 2 mg and 24 mg of DIM, which is both safe and possibly protective.
And you don’t have to be a fan of broccoli to reap the benefits. Other cruciferous veggies like cauliflower, Brussels sprouts, kale, and bok choy also provide DIM. So load up your plate for cancer protection!
And remember, keep an open mind to new ideas, but ALWAYS do your own homework…and combine that with common sense to figure out what’s best for YOU.
4Castañon A, Tristram A, Mesher D, et al. Effect of diindolylmethane supplementation on low-grade cervical cytological abnormalities: double-blind, randomised, controlled trial. Br J Cancer. 2012 Jan 3;106(1):45-52.
5Del Priore G, Gudipudi DK, Montemarano N, et al. Oral diindolylmethane (DIM): pilot evaluation of a nonsurgical treatment for cervical dysplasia. Gynecol Oncol. 2010 Mar;116(3):464-7.
6Dalessandri KM, Firestone GL, Fitch MD, et al. Pilot study: effect of 3,3′-diindolylmethane supplements on urinary hormone metabolites in postmenopausal women with a history of early-stage breast cancer. Nutr Cancer. 2004;50(2):161-7.
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