Effects of a very low fat, high fiber diet on serum hormones and menstrual function implications for breast cancer prevention

Abstract

Background. Low fat, high fiber dietary interventions that decrease blood estrogen levels may reduce breast cancer risk. Asian women consuming their traditional low fat, high fiber diets have lower blood estrogen levels before and after menopause and lower rates of breast cancer compared with Western women. The current controlled feeding study of premenopausal women was designed to determine the effects of a very low fat (10% of calories) and high fiber (35–45g/day) diet on blood estrogen levels and menstrual function. Method. Twelve healthy premenopausal women with regular ovulatory cycles were followed for 3 months. Subjects consumed a diet providing 30% of their energy from fat and 15–25 g of dietary fiber per day for 1 month, and they consumed a very low fat, high fiber ad libitum diet providing 10% of their energy from fat and 25–35 g of dietary fiber per day for 2 months. Results. At the end of the second month of the very low fat, high fiber diet, there was a significant reduction in serum estrone and estradiol levels during the early follicular and late luteal phases. There were no significant changes observed in serum estrone sulfate, sex hormone binding globulin, or progesterone. Despite a significant decrease in serum estradiol and estrone levels after 2 months of a very low fat, high fiber diet, there was no interference with ovulation or the magnitude of the midcycle leuteinizing hormone surge. Small changes in menstrual cycle length of up to 3 days were not ruled out due to the small sample size of the study. Conclusions. A very low fat, high fiber diet in healthy premenopausal women can reduce estradiol and estrone levels without affecting ovulation, thereby providing a rationale for the prevention of breast cancer through a very low fat, high fiber diet.

Adverse Effects of Dietary Habits on Menstrual Disorders in Young Women

“…An experimental vegetarian diet with low calorie was reported to induce menstrual cycle disorders, showing a short luteal phase [60]. In women who have diets with high in fiber, low in fat, or both, concentrations of ovarian hormones or their metabolites were shown to be lower at various points in the menstrual cycle [61][62][63][64][65][66][67]. Low weight and fat mass, low calorie intake and eating disorders are speculated to disturb the pulsatile secretion of pituitary gonadotropins.…”

Dietary fiber intake and ovarian cancer risk: a prospective cohort study

“…High circulating levels of endogenous estrogens have been associated with ovarian cancer etiology (25,26) and there is evidence that older age at menopause is associated with an increased risk of ovarian cancer due to greater exposure to endogenous estrogen (27). There is also evidence that dietary fiber may reduce endogenous sex hormone levels (28,29), specifically serum estrone and estradiol levels in premenopausal women, by increasing sex hormone binding globulin (SHBG) leading to lower circulating levels of unbound or biologically available estrogen (2,3,27,30).…”

“…There is also evidence that dietary fiber may reduce endogenous sex hormone levels (28,29), specifically serum estrone and estradiol levels in premenopausal women, by increasing sex hormone binding globulin (SHBG) leading to lower circulating levels of unbound or biologically available estrogen (2,3,27,30). This may explain, in part, the interaction between dietary fiber and menopausal status observed here.…”

Integrative approaches in breast cancer patients: A mini-review

“…Finally, a high-fiber, low-fat diet works to reduce serum estradiol that may be involved in the progression of hormonal dependent breast cancer [14][15][16]. In addition, these foods appear to increase serum insulin and serum IGF-I levels which appear to stimulate cancer cell growth [17].…”