Diindolylmethane (DIM) is produced during the digestion of indole-3-carbinol (I3C) from cruciferous vegetables like cabbage, kale, broccoli, cauliflower, and brussels sprouts.
I3C and DIM have become common considerations in different aspects of women’s health, including cervical dysplasia and ovarian cancer. They have also been showing some promise in supporting digestive health in intestinal bowel disease (IBD).
ESTROGEN METABOLISM 101
To understand the benefits of DIM and I3C, it helps to understand a little bit about estrogen metabolism. Three biochemical pathways move estrogens through and out of the body. These pathways produce three estrogen metabolites that vary in their activity and potential for harm. The 2-OHE1 pathway produces a “good” estrogen metabolite, and the 4-OHE1 and 16-OHE1 pathways both produce more potentially harmful, “bad” metabolites. They’re problematic because they show persistent estrogenic activity that promotes tissue growth and abnormalities if unmanaged and damage to DNA if unmethylated.
Genetics are a big part of which of these pathways are favoured, but that doesn’t mean you are stuck using the “bad” pathways if that’s what your body leans towards. Research is showing that by encouraging estrogen down the more favourable, protective 2-OHE1 pathway, I3C and DIM show benefits for protecting women’s health and reducing the risk for cancer.
CERVICAL DYSPLASIA
Cervical dysplasia is primarily caused by the sexually transmitted human papillomavirus (HPV) infection. It’s considered “premalignant” and can progress to cervical cancer. In Canada, it’s estimated that three out of four sexually active people will be affected by HPV at least once in their lifetime. For women who contract HPV, many will experience a transient infection that resolves between their assessments. However, those who contract a higher-risk strain may experience cervical dysplasia which can evolve into cervical cancer if left unchecked.
In a small, randomized placebo-controlled 12-week trial, 8 out of 17 participants with cervical dysplasia who received I3C (200–400 mg) had a complete regression at their 12-week biopsy. Because none of the patients in the placebo group experienced regressions, the study was statistically significant and provided important insight into supporting women with cervical dysplasia.
OVARIAN CANCER
It’s estimated that 3000 Canadian women will be diagnosed with ovarian cancer in 2022 and that 1,950 will die from it. Because this is a disease that’s often diagnosed in later stages of progression, mortality is high. In controlled clinical trials, women with advanced stage III and IV ovarian cancer took I3C paired with EGCG (an extract from green tea). Women who took the treatments alongside their chemotherapy had significantly improved 5-year survival, lower CA-125 tumour marker lab results, longer progression-free survival, and fewer ascites compared to those who did not use the combination.
Hopefully, ongoing research in oncology treatments will uncover an option that eliminates this life-limiting disease. In the meantime, progress like this is encouraging for helping women with ovarian cancer.
MEN’S HEALTH
Similar to its beneficial effect on estrogen clearance in women, DIM also shows a positive influence on estrogen and testosterone metabolism for men. Estrogen accumulations can contribute to different health concerns as men age, including atherosclerosis and benign prostatic hypertrophy (BPH). Taking DIM may protect against those conditions. It has also shown reductions in prostate-specific antigen (PSA). This marker is a screening tool in identifying prostate cancer and is also used to assess treatment effectiveness and recurrence.
Management of PSA correlates with a better prognosis for men that have prostate cancer or are recovering from it. Although we need more research to strengthen our understanding of the value of this phytonutrient in men’s health and disease prevention, the studies we have so far are encouraging for DIM.
CROHN’S AND COLITIS
Indole is produced by the gut and is believed to play an important role in protecting the colon from inflammatory damage. Early studies suggest that I3C and DIM from cruciferous vegetables may prevent colitis-associated dysbiosis and inflammation. This is a very exciting prospect for treatment options and disease management for those suffering from IBD!
Despite the similar benefits of I3C and DIM, I recommend choosing DIM for its greater stability and our ability to access DIM's benefits without having to digest I3C.
While the evidence above should encourage you to eat your broccoli and brussels sprouts (consuming these greens is a fantastic source of phytonutrients, as well as being a wonderful part of a healthy diet), it’s easier to get a therapeutic dose of DIM from a supplemental form.
Always check with your healthcare provider first to see what dose is best for your health!
