DIM, also known as diindolylmethane, is a super-potent antioxidant that’s found only in cruciferous vegetables, the ultra-healthy superfood group that includes broccoli, collard greens, and kale, to name a few members.
DIM is a popular supplement for longevity enthusiasts, people looking to combat oxidative damage in the body, and people who want to fight systemic inflammation.
If you want to know more about the science behind the wide-ranging health benefits of DIM, check out our research team’s findings below. We dug up the latest and best science on how DIM could help improve health.
1. DIM has been intensely studied for its beneficial effects on inflammation and free radicals
Diindolylmethane is a metabolite of Indole-3-carbinol, a compound found in cruciferous vegetables including broccoli, red cabbage, cauliflower, collard greens, kale and kohlrabi.
In addition to having anticancer effects, it has been shown to have anti-inflammatory effects and the ability to increase bone mass in animal studies.
Researchers believe that DIM can induce cancer cell death by modulating the expression of Bax/Bcl-2 (regulator proteins that regulate cell death) (1).
2. Diindolylmethane exhibits anti-tumor activity in prostate cancer models
A 2011 study set out to examine whether DIM inhibits the development of prostate cancer using an adenocarcinoma mouse prostate model.
The conclusion of the study revealed positive findings. Feeding the rats DIM inhibited prostate carcinogenesis and induced a substantial reduction in the numbers of viable cells and induced apoptosis in prostate cancer cells.
Researchers concluded that DIM inhibits prostate carcinogenesis via induction of apoptosis and inhibition of cell cycle progression, and induces the death of prostate cancer cells via the mitochondria- and death receptor-mediated pathways (2).
3. DIM could inhibit endometrial cancer cells
Endometrial cancer is the most common form of cancer affecting the female reproductive organs (3). In a study published in Carcinogenesis, the effect of DIM on cell proliferation was examined using a human endometrial adenocarcinoma cell line.
Cells were treated with either a range of concentrations of DIM for 24 hours or with 10 μM DIM for up to 6 days.
Results indicated that after 24 hours of treatment, DIM suppressed growth cell growth by 20 and 40 percent with 10 and 30 μM concentrations, respectively. Researchers also noted that 10 μM DIM inhibited proliferation by 55 percent after four days and by 60 percent after six days of treatment.
In addition, treatments with DIM at concentrations of 50 μM or greater induced apoptosis (4).
4. Diindolylmethane might help increase bone mass
A 2015 study evaluated the effect of DIM on bone mass in mice. Treating female mice with injections of DIM twice a week for four weeks resulted in a significant increase in bone mass.
Furthermore, administration of DIM in ovariectomized mice (ovariectomy induced bone loss in rats and postmenopausal bone loss in women share many similar characteristics) effectively prevented bone loss resulting from increased bone resorption (5,6).
5. Diindolylmethane has anti-inflammatory properties
Due to a correlation between chronic inflammation and the development of a variety of human cancers, researchers have been studying DIM’s anti-inflammatory effects.
In a 2008 issue of The Journal of Nutrition, researchers reported that DIM inhibits the inflammatory responses of murine macrophages. Macrophages are the main pro-inflammatory cells that respond to invading pathogens by releasing many pro-inflammatory molecules, including nitric oxide and prostaglandins.
In addition, downregulation of NF-κB and AP-1 signaling (mediators of inflammatory responses) contributes to the anti-inflammatory actions of DIM (7).
In another study, researchers concluded that DIM can inhibit inflammation of the periodontal tissue in mice after one week of treatment, which promoted alveolar bone recovery in the experimental periodontitis mouse model (8).
Periodontitis is a gum infection that damages the soft tissue and destroys the bone that supports teeth.
These results suggest that DIM may be a future adjuvant therapy for periodontal diseases.
6. DIM might be why cruciferous vegetables reduce the risk of cancer
The cruciferous vegetable family, which includes broccoli, cauliflower, kale, bok choy, cabbage, has been associated with a reduced risk of cancer in numerous epidemiological studies (9).
People whose diets are high in these vegetables appear to have lower rates of certain cancers, which has led researchers to search for biochemical reasons why these vegetables might help prevent regrowth of cancerous cells. DIM is one promising candidate, as it is contained in cruciferous vegetables at high levels, and further, researchers have identified potential biochemical pathways that DIM might manipulate to help slow or stop the growth of cancerous cells.
DIM interacts with estrogen, and many types of tumors are activated by this same hormone, so research papers have proposed a connection between DIM, estrogen, and cancer risk.
However, specific types of cancer that are known to be linked to estrogen, like breast cancer or ovarian cancer, have not been definitely linked to cruciferous vegetable intake or DIM intake, so more research needs to be done to confirm this link.
7. DIM may act against the HPV virus
The estrogen-related mechanism behind DIM’s potential benefit for fighting cancers has led to additional research that may support a use for DIM in treating the human papillomavirus, or HPV, a viral infection that can cause genital warts and cervical cancer (hence the DIM/estrogen connection).
A patent for this application was registered in 2008, and cites potential biological mechanisms by which DIM could assist with treating the HPV virus (10).
However, a clinical trial published in 2011 did not find a significant effect of a 150 mg supplement of DIM on HPV-related symptoms, and with the advent of an vaccine for HPV, it remains unclear whether DIM will be an important agent for treating HPV-related symptoms in the future (11).
DIM side effects
DIM could cause headaches and gastrointestinal side effects. Some reported side effects include darkening of urine, increase in bowel frequency, headache and excess gas (12).
One case report describes visual impairment caused by DIM. In one study, a healthy female patient who took an excessive daily intake of DIM for two months experienced central serous chorioretinopathy, a disease resulting in visual impairment. Symptoms resolved after discontinuing use (13).
DIM could alter the effects of of medications that are metabolized by cytochrome P450. It is believed DIM interacts with cytochrome P450 substrates (enzymes essential for the metabolism of medications); DIM may affect the serum concentration of drugs metabolized by this enzyme (14).
Very high doses of DIM can cause headaches and vomiting. Other research into the safety of DIM has reported that headaches and vomiting can occur with DIM, but this study only noted them at high doses (300 mg taken all at once) (15).
Notably, these side effects only occurred at the highest dose and also only occurred in a variant of DIM that had been specifically engineered for rapid absorption and bioavailability. Headache and nausea were not seen in the regular, garden-variety DIM.
Since this was a single-dose study, it’s unclear whether taking DIM on a daily basis would have improved tolerance to DIM, or would have exacerbated symptoms.
Several clinical trials have been conducted using DIM, and the aggregation of these trials gives some insights into the best way to take DIM for maximum efficacy.
The typical clinical trial uses between 150 and 300 mg of DIM, taken all at once. Other work by researchers at the University of Kansas Medical Center on the absorption bioavailability of DIM gives further insights into the range of doses that’s likely to be tolerable (16). These findings suggest either taking a 150 mg dosage once per day, or a 100 mg dosage in the morning and the evening, for maximum efficacy.
Most studies use at least 100 mg of DIM. The minimum dose of DIM that’s likely to have any biological effect seems to be at least 100 mg, because at a dose of 50 mg, most people do not show any traces of DIM in their blood.
As we saw above, if you are taking a formulation of DIM that’s engineered for maximum absorption, you want to be careful with doses above 200 mg, since 300 mg doses have been associated with side effects like headache and vomiting.
DIM benefits FAQ
Q: What is DIM?
A: DIM stands for diindolylmethane, which is a molecular compound found in vegetables from the cruciferous vegetable family.
It’s been heavily researched as a possible anticancer compound, and appears to exert estrogen blocking effects in some studies as well. DIM is sometimes used alongside hormonal supplements like vitamin D for potentially synergistic effects.
Q: What foods are naturally high in DIM?
A: By far the best natural source for DIM is found in cruciferous vegetables. This family of greens includes Brussels sprouts, kale, broccoli, watercress, and collard greens, to name a few.
Unlike more common nutrients in fruits and vegetables, such as vitamin C, DIM is not really found in significant amounts in any other types of foods, excluding cruciferous vegetables, so make sure you fill up on these if you want more DIM in your diet.
Q: How long does it take for DIM to be absorbed by your body?
A: It can take up to two hours for DIM to be absorbed into your body. One study determined that a dose of DIM will remain at a high concentration in your blood for four to eight hours (17).
Q: How long does DIM stay in your system?
A: DIM is excreted from your body fairly quickly. After you take DIM, it reaches a peak concentration in your blood within two hours or so; every four hours after that, your levels of DIM are cut in half.
That means that by 24 hours, your body’s level of DIM is effectively back to zero. This means that it’s important to either take DIM at the same time every day (e.g. right away in the morning) or split your dosage up into two doses, taken in the morning and in the evening.
Q: What is DIM used for?
A: DIM is popular as a supplement that may target and slow or prevent the growth of certain cancerous cells, at least in preliminary research.
DIM has found some occasional use in the bodybuilding and athletic communities as well due to the belief that it acts as an estrogen blocker. Indeed, DIM has been found to block estrogen receptors in certain studies, which may reduce the effects of estrogen on your system, even though it may not lower your blood levels of estrogen per se.
Related: Our best DIM picks
DIM is a potent antioxidant and anti-inflammatory that could be at the core of why vegetables like kale and broccoli are healthy for you.
It’s been studied intently for its ability to fight free radicals, inhibit cancerous cells, and tamp down on systemic inflammation.
Though not as well-studied in humans as other antioxidant supplements, animal model studies have nevertheless shown that DIM shows significant promise as a supplement.