Antioxidants and hormone-mediated health benefits of whole grains

Antitumorigenic effect of a mammalian lignan precursor from flaxseed

Secoisolariciresinol diglycoside (SD), a mammalian lignan precursor found in high-fiber foods, was isolated from flaxseed and tested for effects on mammary tumorigenesis in rats fed a high-fat (20%) diet. Ingestion of purified SD at 1.5 mg/day for 20 weeks starting 1 week after treatment with the carcinogen dimethylbenzanthracene resulted in a 37% reduction (p < 0.05) in the number of tumors per tumor-bearing rat and a 46% reduction (p < 0.05) in the number of tumors per tumor-bearing rat and a 46% reduction (p < 0.05) in the number of tumors per number of rats in each group. Urinary mammalian lignan excretion significantly increased (p < 0.0001) with SD treatment, indicating the conversion of SD to mammalian lignans. No enlargement or gross abnormalities of the major organs were observed in the SD-treated rats. This study showed, for the first time, that SD has an antitumor effect when provided at the early promotion stage of tumorigenesis and may contribute to the health benefits of high-fiber foods.

Whole grain intake and cancer: a review of the literature

There has been little research concerning the health effects of whole grain intake in humans. We have synthesized 15 american and European case-control and prospective studies of whole grain intake. Most subjects were middle aged or older. The studies employed disparate dietary methods, and the foods referred to and quantities eaten are ill defined. Nevertheless there is a striking consistency in reduced risk for colorectal and gastric cancers associated with intake of whole grain, also found in isolated studies of endometrial cancer and coronary heart disease. Because reduced risk was not associated with refined grain intake, these findings do not appear to be confounded by participant confusion concerning refined vs. whole grains. The independence of these findings from reduced risk associated with fruit and vegetable intake is not established. There should be further research to establish whether whole grain intake is protective against chronic disease.