The Influence of Dietary Protein and Carbohydrate on the Principal Oxidative Biotransformations of Estradiol in Normal Subjects*

Abstract

Dietary protein, when substituted for carbohydrate or fat, can increase cytochrome P-450-dependent drug oxidation rates in humans. Endogenous estrogens, as well as drugs, are also metabolized by cytochrome P-450 and other enzymes in the hepatic endoplasmic reticulum. Therefore, it was of interest to determine whether variations in diet can alter the major metabolic pathways for estrogens, as assessed by radiometric methods. Eight normal men were fed a high protein diet (44% of calories as protein, and 35% as carbohydrate for 2 weeks), followed by a high carbohydrate diet (70% of calories as carbohydrate and 10% as protein) for an additional 2 weeks. The fat and total energy contents of the two diets were equal. The percent oxidation of [2-3H]estradiol, measured as 3H2O released, which is an in vivo measure of 2-hydroxylation of endogenous estrogen, was greater in all eight men during the high protein dietary period than during the high carbohydrate dietary period (44 +/- 3% and 33 +/- 3%, respectively, means +/- SE, P less than 0.005). In contrast, 16 alpha-hydroxylation of estrogen, as measured using [16 alpha-3H]estradiol, did not change significantly. Our findings demonstrate that dietary components can alter estradiol oxidation in humans and that the 2- and 16 alpha-hydroxylases for estrogen are under separate regulatory control. The influences of specific nutrients on estrogen metabolism may have potential significance for diseases in which these hormones may play a role in clinical expression.

Body composition in young adults with inborn errors of protein metabolism—A pilot study

“…High intake of simple sugars, in the form of soft drinks, has been associated with reduced bone mineral density in adolescents (Wyshak 2000). In addition, the macronutrient and phytochemical composition of the diet is known to influence sex steroid metabolism (Adlercreutz et al 1987;Anderson et al 1984;Berrino et al 2001;Dorgan et al 1996;Goldin et al 1994). Whether the observed difference in bone density between male and female patients, relative to control subjects, represents a true gender difference or a coincidental finding is presently unclear.…”

The onset of puberty and the availability of sex steroids in female gymnasts

“…Warren (1980) proposed that a large energy drain may have an important modulatory effect on the hypothalamic pituitary set point at puberty. Dietary protein and carbohydrate intake influence estrogen metabolism (Anderson et al, 1984). Physical and hormonal pubertal development are also related to daily fiber intake in pubertal girls in contrast to daily energy or fat intake (de Ridder et al, 1991).…”

Diet and Breast Cancer

“…Furthermore, a high protein diet considerably diminished 4-ene-5cr-reduction of T and enhanced 2-hydroxylation of E2 (13,14). We could recently confirm that a high dietary protein/carbohydrate ratio is associated with a high urinary excretion of catecholestrogens ( 15).…”