Mechanisms throught which dietary and nutritional factors may influence estrogen metabolism

MECHANISM OF ACTION	NUTRIENT
Promote C – 2 hydroxylation over C – 4 and/or C – 16 hydroxylation of estrogens	Cruciferous vegetables, indole-3-carbinol (I3C), isoflavones (soy, kudzu)
Reduce the oxidation of catechol estrogens (2 – OH and 4 – OH)	Vitamins A, E & C, N-acetylaysteine, tumeric, green tea, lycopene, a-lipoic acid, favonoids
Promote the methylation of catechol estrogens (2 – OH and 4 – OH)	Folate vitamins B2, B6 & B12, nmethylglycine, magnesium
Increased circulating concentrations of sex hormone binding globulin (SHBG), thus reducing levels of unbound, active estrogens	Fiber, lignans (flaxseed), isoflavones (soy, kudzu)
Inhibit the activity of aromatase, which converts testosterone and androstenedione into estradiol and estrone, respectively.	Lignans (flaxseed), isoflavones (soy, kudzu)
Promote the detoxification of estrogens by up-regulating Phase I and Phase II enzymes	Tumeric (curcumin), D-limonene, magnesium, vitamins B2, B6 & B12 flavonoids
Inhibit the activity of glucuronidase, which deconjugates estrogens in the large intestine, allowing them to be reabsorbed and re-metabolised	Fiber, probiotics (acidophilus, bifidobacteria), calcium D-glucarate
Modify estrogen receptor activity	Isoflavones (soy, kudzu), lignans (flaxseed), indole-3-carbinol