What is it about tomato sauce that might prevent cancer?

Evidence is building that the secret ingredient might be lycopene. Related to beta carotene, it’s found in high levels in tomatoes and pink grapefruit. Lycopene seems to be a strong antioxidant and might have stronger anticancer effects than beta carotene.

Cooked tomatoes appear to contain more usable lycopene than raw ones, especially when the tomatoes are cooked in oil. The lead researcher on the Harvard study has a theory as to why. “Probably what’s happening is that the lycopene is in the cell walls, and it’s hard to get at,” says Edward Giovannucci. “If you just eat a tomato, a lot of the lycopene passes through. But if you cook tomatoes in a little oil, then the cell walls break down with the heat, and the lycopene gets absorbed into the oil.”

How much tomato sauce (or other tomato-based foods) should you eat? Studies have found apparent anticancer benefits in people who consume from one to seven servings of tomatoes a week.

You might also try purified lycopene. Some commercial formulations claim to offer the equivalent of one complete serving of fresh tomatoes in a single tablet. The safety of concentrated lycopene in supplement form has not been established, particularly in women who are pregnant or breastfeeding.