IP6, a major dietary source of inositol phosphates, is a physiological antioxidant with potential to form complexes with cations linked to cell proliferation and hypercholesterolemia. Accordingly, we have examined the action of IP6 on dietary modulation of neoplasia and hyperlipidemia in a Fischer rat model (1, 2). Two studies were conducted on the effects of naturally-derived IP6, administered as purified phytate, a salt form of phytic acid (inositol hexaphosphoric acid). One study examined the effect on the growth of tumors promoted in syngeneic rats transplanted with a viral oncogene-transformed cell line. Increases in tumor incidence and growth rate of fibrosarcomas seen following administration of a special diet (containing 5% saturated fatty acids and 1.2% magnesium oxide) were completely mitigated by supplementation of the same diet with purified potassium-magnesium phytate (8.9% phytic acid by weight). The other study examined the IP6 effect on serum lipid and mineral levels in animals fed a cholesterol-enriched or standard diet. Elevated levels of serum total cholesterol, triglycerides and zinc/copper ratio associated with administration of the cholesterol-enriched diet were significantly lowered by supplementation of this diet with monopotassium phytate. Addition of monopotassium phytate to the standard diet also reduced serum lipid levels but did not significantly affect the zinc/copper ratio. These studies support a role for IP6 as a potential therapeutic agent in the treatment of cancer and hyperlipidemia.