Inositol hexaphosphate (“IP6”, “myo-inositol hexaphosphate” or “phytic acid”) is a natural carbohydrate molecule present in most plant and animal cells. You get this stuff in your diet mainly from eating cereals, grains, legumes and meat. Your body can also make IP6 from inositol.
It is known to be involved in regulating numerous intracellular functions, such as signal transduction, cell growth and differentiation, platelet function and cholesterol metabolism.
Anticancer Activity of IP6 (and Inositol):
Animal and cell studies have reported that IP6 is effective in cancer prevention and control of tumor growth, progression, and metastasis. Its anticancer activity likely involves IP6’s immune stimulatory, potent antioxidant and antiangiogenic effects.
Researchers have also discovered that when IP6 is combined with inositol, there is a significant synergistic effect against a variety of cancer types in cell and animal studies (i.e. colon, breast, lung, etc.) that far exceeds the anticancer activity of the individual compounds alone.
Studies performed on breast cancer cells have demonstrated increased efficacy of two commonly used breast cancer drugs (doxorubicin and tamoxifen) when combined with IP6. What I find most interesting was that the authors reported that this anticancer effect was particularly effective against estrogen receptor-negative and doxorubicin-resistant breast cancer cells.
Unfortunately, we don’t have any studies actually done in patients to examine if the anticancer activity found in cancer cells and in animal studies is relevant clinically in humans.
The best (albeit very small) clinical study I found looked at the use of IP6 and inositol versus placebo in breast cancer patients receiving 6-months of chemotherapy. The authors reported significantly higher quality of life (50% less symptoms) and protection against white blood cell and red blood cell decreases in the patients receiving the IP6 and inositol versus those who received the placebo.
Dosing Used In This Study:
Dose: IP6 + Inositol powder (3 grams given twice-per-day for 6-months)
The authors stated that this dose was likely too low to see any anticancer activity as the effective dose levels used in animal studies extrapolated to humans would be higher. They wrote:
- “Extrapolated from animal data, in the absence of a dose-determination study in humans, the recommended prophylactic dosage of IP6 + Inositol is 1-2 g/day and a cancer therapeutic dosage is 8-12 g/day [ref]. Even though our dosage was low, its efficacy to diminish the side effects of chemotherapy was significant. Recent phase I study of inositol for lung cancer chemoprevention showed that in a daily dose of 18 g for 3 months, inositol was safe and well tolerated [ref].”
IP6 has anti-platelet activity, so it may increase the risk of bleeding when used with other anticoagulants or anti-platelet drugs.
IP6 can also bind with calcium, iron, magnesium, and zinc in the stomach and reduce their absorption.
As always, discuss your use of any supplement with your physicians before taking them.
Dr. Lawenda’s Bottom Line:
In the absence of any high quality, large-scale studies the data is not strong enough at this time to say definitively whether IP6 is beneficial for having any anticancer activity in humans. As we all know, it is very common to see promising anticancer activity from many proposed cancer therapies in preclinical studies that after being put to the test in confirmatory human studies simply don’t work. I remain cautiously optimistic on the potential anticancer effects of IP6.
Additionally, the data showing IP6’s ability to support quality of life during cancer treatment comes from a limited number of very small and underpowered studies and case reports. We need to await larger confirmatory studies to know if IP6 has these beneficial effects as well.
All that being said, since the side effect profile of IP6 is very low (see precautions above), there is no major downside for those of you who want to give it a try.