A dietary supplement derived from tomatoes may help treat moderately elevated blood pressure, the results of a small study suggest.

Researchers in Israel found that a daily dose of tomato extract helped lower blood pressure among 31 men and women with mild hypertension. On average, their systolic pressure -the top number in a blood-pressure reading -dropped 10 points, while their diastolic pressure, or bottom number, dipped four points, both statistically significant differences.

The supplement, sold as Lyc-O-Mato, contains several plant compounds found in tomatoes. Among them is lycopene, an antioxidant that some studies suggest may lower the risk of cardiovascular disease.

Antioxidants, such as lycopene and vitamins C and E, help neutralize oxygen free radicals - molecules that are a natural byproduct of metabolism - can damage body cells over time. This “oxidative stress” is thought to contribute to a range of chronic diseases, including heart disease.

The antioxidant effects of the tomato extract may explain its apparent benefit on blood pressure, according to the report in the American Heart Journal.

People who have mild high blood pressure or who have high-normal blood pressure would be the “ideal candidates” for treatment with the extract, said study co-author Dr. Esther Paran of the University of the Negev in Beer Sheva. It’s these individuals, she noted, who are often advised to use lifestyle changes to rein in their blood pressure levels.

However, people who are already being treated for high blood pressure should talk with their doctors before trying tomato extract, Paran told Reuters Health.

The study included adults ages 30 to 70 with stage 1 hypertension, defined as a systolic blood pressure between 140 and 159 mm Hg, and a diastolic pressure between 90 and 99 mm Hg. Blood pressure is considered normal when it is below 120/80; anything between that and 140/90 is considered “prehypertension.”

Study participants spent 4 weeks taking a placebo, or inactive, capsule each day, after which they were given a tomato extract capsule every day for 8 weeks. Finally, they spent another 4 weeks on placebo capsules.

LycoRed-Natural Products Industries, the maker of Lyc-O-Mato, supplied the extract.

During the treatment period, the group’s average systolic blood pressure fell from 144 to 134 mm Hg, while their diastolic pressure dipped from 87.4 to 83.4 mm Hg.

At the same time, blood samples showed that certain markers of oxidative stress had declined - suggesting that the supplement’s antioxidant activity was responsible for the blood pressure benefit, according to the researchers.

Eating a diet rich in tomato products and other antioxidant-containing fruits and vegetables is certainly a smart move, Paran said. But, she added, a person would need to down about four tomatoes to get the nutrients in one tomato extract capsule.

In addition, Paran said, lycopene and other antioxidant compounds in tomatoes are fat-soluble, so they are more readily absorbed when taken with the oil used in the capsule.

However, she and her colleagues note that larger and longer-term studies are still needed to determine where tomato extracts fit into high blood pressure management.

SOURCE: American Heart Journal, January 2006.