Glucaric acid is combined with calcium to form calcium D-glucarate. Glucaric acid is found in tissues and body fluids. Glucaric acid is also found in foods such as fruits and vegetables including oranges, apples, Brussels sprouts, broccoli, and cabbage.
There is a lot of interest in using calcium D-glucarate for preventing estrogen-related cancer such as breast cancer and other hormone-related cancers. Calcium D-glucarate is thought to decrease estrogen levels by affecting estrogen's elimination. Estrogen is normally metabolized hepatically in phase II metabolism by combining with glucuronic acid. It's then excreted in the bile, but a bacterial enzyme in the intestine called beta-glucuronidase normally breaks the estrogen-glucuronide bond, allowing estrogen to be reabsorbed. Calcium D-glucarate works at this step by inhibiting beta-glucuronidase. Blocking this enzyme is thought to decrease the amount of estrogen that is reabsorbed and lower circulating estrogen levels.
There is some evidence that beta-glucuronidase activity might be increased in patients with hormone-dependent cancers like breast and prostate cancer. Dietary glucarate can inhibit beta-glucuronidase activity and inhibits animal models of mammary tumor development. In vitro, D-glucarate decreases tumor cell proliferation.