DIM – Diindolylmethane

December 9, 2009 Written by JP    [Font too small?]

Kids often times wonder why things are the way they are. Parents know this phenomenon all too well. Rarely does a word strike as much dread in a father and mother’s heart as the word “why”. The answer to such a question usually isn’t that complicated. But rather it’s the understanding that any answer given will often prompt the follow up question – “But, why?”. I think I may be able to help out with this. The next time you instruct your daughter or son to eat their broccoli, Brussels sprouts or cauliflower and they ask you why, you can simply tell them that: “Cruciferous vegetables contain glucosinolates that assist the body in detoxifying xenochemicals and discouraging aberrant cellular and hormonal processes that can ultimately result in malignancies”. Works every time!

In March 2007 a paper was presented by the Linus Pauling Institute at Oregon State University. The topic was the role that cruciferous vegetables play in reducing “human cancer risk”. The OSU researchers focused on two specific components found in cruciferous vegetables known as indole-3-carbinol (I3C) and DIM (diindolylmethane), and their proposed effect on cervical dysplasia (CD). CD is a growth of abnormal, precancerous cells in the cervical region (between the vagina and uterus). This condition is frequently caused by exposure to the human papilloma virus (HPV). Without proper treatment, it is estimated that between 30 – 50% of CD cases will result in an invasive and sometimes deadly form of cervical cancer. This concern has lead to the widespread promotion of a controversial vaccine (Gardasil) which is intended to reduce this risk. (1,2)

Women who are diagnosed with cervical dysplasia are categorized in three different stages. CIN refers to “cervical intraepithelial neoplasia”.

  • CIN I – The mildest form of CD – 1/3 presence of abnormal cells.
  • CIN 2 – Moderate dysplasia – 2/3 abnormal cells in the cervix.
  • CIN 3 – Severe dysplasia – more than 2/3 precancerous cells.

A recent study published in the journal of Gynecologic Oncology suggests that DIM may one day offer a viable adjunct to more invasive treatments for all stages of CD. 64 women with “biopsy-proven” CINs (stage 2 and 3) were divided into two groups. 45 of them were given a DIM supplement at a dosage of 2 mg/kg daily for 12 weeks. The remaining 19 women took a similar looking placebo. Post-study analysis was conducted every 3-4 months for the following year. Tests included biopsies, colposcopies, HPV testing, Pap smears and physical exams. (3)

  • At the beginning of the research, 58% of the volunteers were diagnosed as having CIN 2 lesions and 42% had CIN 3 lesions.
  • 47% of the DIM users showed improvements in their CIN classification. On average the benefits were noted after 5 months.
  • 49% of those given DIM demonstrated “less severe abnormality or normal result” in their subsequent Pap smears.
  • A 56% improvement in colposcopy testing was also revealed in the DIM group. 72% of these women “had a decrease in lesion numbers”.
  • The only reported side effects (in two participants) was nausea.

This current trial is supported by another recent experiment conducted in a mouse model. That research concluded that “DIM delays or inhibits the progression from cervical dysplasia to cervical cancer”. The scientists from Hackensack University Medical Center noted that part of the benefit of DIM involves a beneficial alteration of estrogen metabolism and an enhancement of immune response. A previous trial involving women with a history of breast cancer substantiates a healthful shift in the processing of estrogen as well. (4,5)

I3C Converts Into DIM in the Body to Combat Cervical Cancer
Estradiol=Estrogen   Genistein=Soy   W-3-Fatty Acids=Fish Oil
Source: J. Nutr. 136:2676S-2678S, October 2006 (link)

Whenever a substance is extracted from a natural food it doesn’t necessary function in the same way as the entire food itself. Vegetable extracts, such as DIM, are often highly concentrated and purified prior to initiating any type of animal or human trials because: a) scientists hope to magnify the beneficial effects of the whole food and; b) they want to create a “medicine” or supplement that can be easily reproduced and measured for scientific study. For instance, 500 mg of broccoli will contain varying amounts of natural minerals, phytochemicals and vitamins. But 500 mg of DIM will provide a consistent amount of the “active” ingredient. In short, purified extracts allow for the more precise study of a substance.

The safety of cruciferous vegetables is very well established. Most doctors and nutritionists are more than happy to encourage patients to eat more bok choy, collard greens or kale. But DIM, just like most supplements, is viewed more as an experimental medicine than a food. Therefore, testing has been conducted to determine whether “medicinal” dosages of DIM are indeed safe. Thus far, studies in both animals and humans indicate that DIM is relatively non-toxic. An experiment from October 2008 determined that dosages of up to 200 mg of DIM (per serving) were well tolerated. Higher, individual dosages of 300 mg did however invoke “mild nausea and headache” and one incident of vomiting. That said, no significant toxicity has been reported in any of the animal or human trials that I’ve reviewed. (6,7,8)

The most current studies involving DIM in the management of cervical dysplasia and breast cancer utilized a specific DIM supplement known as BioResponse DIM. This product combines DIM with soy phosholipids (components of lecithin) and Vitamin E. This combination appears to enhance the absorption and activity of unbound DIM. At present, this is the best researched product of its kind. For this reason it is currently featured in products manufactured and distributed by numerous supplement companies.

If you’re concerned about your risk for a variety of malignancies, including cervical cancer, you may want to discuss this natural option with your health care providers. I’ll likely cover DIM in future columns as well. At the moment there are several studies underway that are examining its applicability in both breast and prostate cancer. The results of those trials will likely provide a great of additional information. In the meantime, this may be a good reminder to eat more cruciferous vegetables without having to ask “why”.

Be well!


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Posted in Alternative Therapies, Detoxification, Nutritional Supplements

13 Comments & Updates to “DIM – Diindolylmethane”

  1. Nina K. Says:

    Thanks JP,

    you always reminds us women to eat healthy. i had a few breast cancer patients in earlier times as i worked as a physiotherapist and i hope and pray that i will never never get cancer. My doctor told me that hes worried about the fact that more and more very young women have malignancies. he – i too – believed that the lifestyle changes and bad nutrition are playing a major role in this context.

    so women, take care of you health.

    Greetings to “the other side” 🙂
    Nina K.

  2. JP Says:


    That worries me too. But, as you know, the best antidote for worry is to be informed and proactive. You certainly embody both of those qualities! I’m sure that makes a big difference! 🙂

    I send you back greetings from the land of sunshine … where another storm is quickly approaching! 🙂 I love Winter!

    Be well!


  3. liverock Says:

    I have never been able to ascertain whether I3C or DIM is better for getting safer estrogen metabolism. Maybe they are pretty much the same.
    Men should also strive for the sake of their prostates to get optimun estrogen levels, as high estrogen in older men appears to signal prostate problems.
    Thanks for the article, its a timely warning for both men and women.

  4. JP Says:

    Thanks, Liverock!

    I couldn’t agree more with your prostate observation. In fact, the vast majority of clinical trials on DIM (currently underway) are studying it’s effect on PCa.

    It’s hard to objectively sort through the 13C/DIM debate. There has been one preliminary trial (in test animals) that suggests that 13C *could* have a greater impact on the processing of certain medications – via CYP1A1 and CYP1B1 expression.



    A 2007 review concluded that I3C had more evidence to back it’s use – which is does. However, the study was sponsored by a company that includes I3C (Metagenics) in their product line. A 2008 review presented a more pro-DIM take with regard to this issue.



    I’m sure the results of the upcoming trials will help to better establish the relative efficacy and safety of DIM. Here’s hoping for positive findings!

    Be well!


  5. Bill Rawls Says:

    Great article, JP. The effect is real. I have known several patients who were able to reverse dysplasia with high intake of cruciferous vegetables. I usually tell them to add in green tea and regular consumption of berries to their daily diet also.

    It should be noted, however, that glucosinolates are toxic to thyroid and liver tissue. This does not appear to be a pronounced effect, but individuals suffering from thyroid disease or liver disease should take note. It may be that indole-3-carbinol and DIM are less toxic than other glucosinolates, but I have not been able to find enough evidence to say for sure. If this were the case, supplements would be superior to diet.

    Either way, it appears benefits outweigh the risks for most people. I recommend a routine check of liver and thyroid function at yearly exams for those eating higher than average amounts of cruciferous vegetables or taking supplements.

  6. JP Says:

    Excellent points, Bill. Thank you for sharing that! 🙂

    Be well!


  7. Lee Says:

    I am trying i3c, lemon balm and cortitrol to lower my thyroid functioning…. so far t3 and t4 numbers are now in normal range but tsh stubbornly at 0.01 … it’s only been a few weeks

  8. JAlt Says:

    So, if a person has an underactive thyroid function, should they leave aside DIM supplementation? Why?

  9. JP Says:

    Hi Jalt,

    I contacted a source associated with a well respected DIM supplement. Here is his reply to your question:

    “Use of DIM by individuals with hyperactive or hypoactive thyroid status is not a problem.

    Cruciferous vegetables contain a great number of substances besides DIM (diindolylmethane). DIM is unrelated to other distinct phytochemicals found in certain cruciferous plants which have been shown to impact thyroid function in animals. The substance, (-)5-Vinyloxazolidine-2-thione (goitrin), a well-known goitrogen, is the primary anti-thyroid compound that would lower thyroid function and make medication less effective. Goitrin is completely distinct and different from DIM. There is no goitrin present in ********** supplements, only pure DIM. The DIM itself has no impact on thyroid function. We cannot make this statement regarding DIM supplements from other manufacturers.”

    I would only add that DIM *may* have some positive effects with regard to proliferative thyroid disease:


    Be well!


  10. Dana Rogers Says:

    This may seem like a crazy question. but..Do you know if DIM would be safe for children? My child has medical issue that prevent him from eating most things, so he lives on pediasure and sidekicks. I have tried the green supplements recommended for children but he tastes it and wont take it. thinking if this has all the vitamins that you get out of the green veggies maybe this will help to get some vitamins in him. Just desperate as he is 6 and finding any way to get things in him that will help with his health.

  11. JP Says:

    Hi Dana,

    Not a crazy question at all! IMO, DIM would not be appropriate as a substitute for veggies in your son’s diet. It’s a very specific isolate taken from cruciferous vegetables, but lacks many of the other nutrients and phytochemicals present in foods such as broccoli, cabbage, cauliflower and kale. In order to answer your question in a more precise manner, I would need to know what your son needs to avoid in his diet. There may be ways of hiding/masking certain vegetables in recipes or opting for supplements that provide broader extracts of fruits and vegetables. Encapsulated fruit and vegetable juice extracts are one possibility.

    Be well!


  12. Dana Rogers Says:

    thanks JP
    My son has no allergies he has extreme sensory oral aversion. He lives on sidekicks, some medical juices although one made him throw up so now he is of them and pedisure. He is very quick to gag and throw up. We were going to tube him but doc pulled it off the table last year to send him to a feeding therapist but after 7 months she threw the towel in. and now that he is 6 it’s not too late to tube, but trying to do it naturally before diving into the tube option again. He will eat a few bites of grilled cheese sandwich and mac-n cheese like 3 bites and done. no veggie or fruits unless a juice but the juice has to be not thick. has to be like orange juice, thinner in it’s consistency.
    is there a GREAT veggie juice that is out there?

  13. JP Says:

    Hi Dana,

    If your son accepts them, I suggest making homemade juice from fresh, organic ingredients. I know this would require some investment (the juicer + more expensive fruits and vegetables) and preparation time. But, the nutritional advantage would be significant. There are many healthful recipes out there. A few examples:

    Recipe # 1

    + fresh spinach (vibrant green color and a mild, smooth taste)

    + green or red apple (with peel)

    + lemons or limes (juice them with the skins)

    Recipe #2

    + fresh berries (blueberries, strawberries)

    + fresh spinach

    + fresh coconut (the flesh or meat only)

    Recipe #3

    + fresh carrots

    + fresh oranges

    + fresh ginger root

    You can always experiment with the recipes first and adjust the proportions of the ingredients to enhance the flavor.

    Ultimately, these simple juices (and others like them) provide greater nutrition (including natural enzymes) than commercial juices.

    IMO, commercially available juices are trickier. Here are some options:


    Be well!


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