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Grapefruit seed extract may help heal stomach ulcers, say Polish researchers.

In their study they tested different doses of grapefruit seed extract on rats with stomach ulcers. Results showed a drop in gastric acid, which irritates and damages stomach tissue. Treatment with grapefruit seed extract also resulted in a shrinking of the ulcer size and an increase in blood flow to the ulcers, which may help them heal.

Grapefruit seeds aren't normally eaten, but supplements of grapefruit seed extract are available. However, the researchers aren't recommending (or rejecting) such supplements. Their study did not include any people.

The findings were presented in Chicago at the Digestive Disease Week 2005 conference.

Rat Test: Ulcers vs. Extract

Doses were scaled to the rats' weight. At a dose of 10 milligrams/kilogram, acid secretion was halved in rats with stomach ulcers. The ulcers also shrank progressively by the sixth and ninth days of treatment and had completely healed after 16 days, according to the study.

The rats also showed a significant increase in blood flow to the ulcers, and they released more of an ulcer-healing chemical called gastrin, say the researchers, who included Thomas Brzozowski, MD, PhD, of Poland's Jagiellonian University Medical College.

The extract could have something to do with Cox-1 and Cox-2 activity, say Brzozowski and colleagues.

Cox-1 is an enzyme found in many parts of the body, including the stomach. It helps the stomach produce mucus, which protects it from tissue-damaging acids. Many common pain relievers, like aspirin, inhibit this enzyme, reducing mucus production in the stomach, which increases the risk of ulcers and severe irritation with bleeding.

Cox-2 enzymes also produce chemicals linked to inflammation. The popular pain reliever Celebrex inhibits Cox-2.

When the researchers paired the extract with drugs that inhibit the Cox enzymes, the extract's effects in healing ulcers were inhibited or completely wiped out.

Grapefruits Too Tart to Eat?

Grapefruits aren't off limits for people with ulcers, says Brzozowski in a news release.

"Because grapefruit is acidic in nature, people with ulcers might assume that they should not include the fruit in their diet. However, this research suggests the exact opposite," he says.

Antioxidants in the extract may be the key ingredient, he says.

The antioxidant properties found in grapefruit and the ability of the extract to limit damage in the stomach's lining have therapeutic implications that when combined with other therapies can be beneficial for healing stomach ulcers, he says.

Supplement Savvy

Grapefruit and grapefruit juice may increase the amount of some medications in the bloodstream. That includes cholesterol-fighting statin drugs, calcium-channel blocker drugs for high blood pressure, and some antihistamines.

Consult a doctor with any questions about grapefruit's effects or an appropriate amount to consume. Also, tell your doctor about any supplements you're taking, including over-the-counter items, herbal products, and vitamins. That way, your doctor can watch out for possible drug interactions and discuss the pros and cons of treatments.

Consumers may also want to keep in mind that the U.S. government does not regulate dietary supplements.

By Miranda Hitti, reviewed by Brunilda Nazario, MD

SOURCES: Digestive Disease Week 2005, Chicago, May 14-19, 2005. News release, Spectrum Science. WebMD Medical News: "What Could Possibly Be Bad About Grapefruit?"