Scientists have long believed that the carotenoids found in fruits and vegetables have a cancer-preventive effect. In particular, epidemiological studies have found that as the consumption of tomato products increases, risk of certain types of cancer decreases.

Researchers at Ben Gurion University and Soroka Medical Center in Beer Sheva, Israel, are engaged in research aimed at discovering the mechanism(s) of action that would explain this relationship between tomato consumption and cancer prevention.

In a study published in Molecular Cancer Therapeutics, Drs. Yoav Sharoni and Joseph Levy reported that carotenoids, well known for their antioxidant activity, also act to prevent cancer by stimulating the body's antioxidant response element. Stimulation of the antioxidant response element is an established mechanism for the mobilization of the body's defense system against carcinogens and other harmful compounds. By activating this system, tomato carotenoids induce the production of phase II detoxification enzymes. These enzymes convert carcinogens, which can cause DNA mutations that lead to cancer, into products that are less toxic and are readily excreted from the body.

Asked about the importance of this new research, Sharoni stated, "This is the first work to show that lycopene and other carotenoids activate the antioxidant-response element. This is a completely novel discovery."

The importance of this research lies in the implications the results carry for improving the health of the general public. Levy suggested, "A diet rich in tomato products may help trigger unique cancer-preventive mechanisms. Thus, people should add increased amounts of tomato phytonutrients from tomato products or tomato extract supplements to their daily diet" (Ben-Dor A, Steiner M, Gheber L, et al., “Carotenoids activate the antioxidant response element transcription system.” Mol Cancer Ther, 2005;4(1):177-86).