Calcium Glucarate

Health Care Professional Information

Scientific Name
d-Glucaric acid salt
Common Name

Glucarate, calcium-d-glucarate, calcium saccharate, calcium-d-saccharate

Clinical Summary

Calcium glucarate is the salt and the commercial form of glucaric acid. Glucaric acid occurs naturally in a variety of foods, including oranges, broccoli, and potatoes (1). Calcium glucarate and other derivatives have been used to prevent and treat cancer. Patients with breast cancer often self-medicate with supplements of calcium glucarate following surgery or adjunctive treatments. The glucarate component, not the calcium, is thought to account for its activity. Following administration, glucarate is converted to d-glucaro-1,4-lactone, which inhibits beta-glucuronidase (4). In vitro and animal studies suggest that inhibition of beta-glucuronidase may prevent carcinogenesis (5), as well as inhibit the initiation and promotion of cancer cells (3) (6). Increased elimination of carcinogens and hormones, including estrogen, has also been shown (2).

Human studies have not been conducted to evaluate the safety or efficacy of calcium glucarate for cancer treatment.

Food Sources

Cruciferous vegetables, apples, grapefruit, lettuce, bean sprouts, grapes
(1)

Purported Uses
  • Cancer prevention
  • Cancer treatment
  • Detoxification
Mechanism of Action

The glucarate component, not the calcium, accounts for the activity of this supplement. Calcium glucarate is absorbed from the gut as D-glucaric acid. D-glucaric acid is further converted to D-glucaro-1,4-lactone, which is thought to inhibit the activity of beta-glucuronidase (4). Beta-glucuronidase has been shown to decrease the rate of elimination of estrogen and carcinogens (e.g. polycyclic aromatic hydrocarbons and nitrosamines) by deconjugation (3). Inhibition of beta-glucuronidase activity with calcium glucarate is thought to improve excretion of metabolized estrogen and carcinogens (2). D-glucarate can also be metabolized by gut bacteria, inhibit bacterial beta-glucuronidase, and potentially alter the enterohepatic cycle. D-glucarate may also interact with signal transduction pathways altering promotion and initiation of cancer cells (4).

Pharmacokinetics

Animal studies
D-glucarate salts are absorbed in the stomach as D-glucaric acid or metabolized by gut bacteria. D-glucaric acid is converted to D-glucaro-1,4-lactone and D-glucaro-6,3-lactone. D-glucaro-1,4-lactone is extensively distributed throughout the body, present in all tissues and body fluids (4). Excretion is primarily in the urine with minimal amounts present in feces and (1).

Adverse Reactions

No adverse reactions have been reported.

Herb-Drug Interactions

Oral birth control / hormone replacement: Theoretically glucarate may reduce serum levels of estradiol and other hormones metabolized by glucuronidation pathway.
Entacapone: Theoretically glucarate may alter the metabolism and excretion of entacapone.
(4)

Literature Summary and Critique

The safety and efficacy of calcium glucarate have not been evaluated in humans.

Dosage (Inside MSKCC Only)
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Consumer Information

How It Works

Bottom Line: Calcium glucarate has not been shown to treat or prevent cancer.

Calcium glucarate is absorbed in the intestine and converted into a molecule (D-glucaro-1,4-lactone) that inhibits beta-glucuronidase, thereby increasing the amount of carcinogens that can be eliminated by the body. For example, rats that were exposed to carcinogens and fed calcium glucarate during the initiation and progression of their tumors had a slower onset of tumor development and a smaller number of tumors than rats that were not fed calcium glucarate. Calcium glucarate also increases the rate of estrogen elimination, which may reduce estrogen levels in the body. This explains its preferential use in estrogen-sensitive breast cancer.
However, positive results in studies in animals do not always mean that a drug will work in humans. No clinical trials have tested whether calcium glucarate has these effects in humans.

Purported Uses
  • To detoxify the body
    Laboratory and animal studies suggest that calcium glucarate speeds up the elimination of carcinogens from the body. Human studies have not been conducted.
  • To prevent and treat cancer
    A handful of studies show that calcium glucarate can slow the development and reduce the number of tumors in rats exposed to carcinogens. Human data are lacking.
Do Not Take If
  • You are taking birth control pills (Because calcium glucarate can increase the elimination of estrogen from the body, it may render oral contraceptives ineffective).
  • You are taking hormone replacement therapy (HRT) (Because calcium glucarate can increase the elimination of estrogen from the body, it may render hormone replacement therapy ineffective).
  • You are taking entacapone (Comtan®) (In theory, calcium glucarate may increase the elimination of entacapone from the body, making it less effective).
Side Effects

None known

E-mail your questions and comments to aboutherbs@mskcc.org.