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.