Daily tomato consumption may cut skin cancer risk in half, according to a new study in mice.

The Ohio State University researchers report their findings online in the journal Scientific Reports.

Male mice fed a diet of 10 percent tomato powder daily for 35 weeks, who were then exposed to ultraviolet light, experienced, on average, showed a 50 percent decrease in skin cancer tumors compared to mice that did not eat the tomato powder.

The skin cancer protection is likely coming from the carotenoids, the researchers speculate.

There were no significant differences in tumor number for the female mice in the study. Previous research has shown that male mice develop tumors earlier after UV exposure and that their tumors are more numerous, larger and more aggressive.

Older human clinical trials suggest that eating tomato paste over time can dampen sunburns, perhaps thanks to carotenoids from the plants that are deposited in the skin of humans after eating, and may be able to protect against UV light damage, says Jessica Cooperstone, co-author of the study and a research scientist in the Department of Food Science and Technology in the College of Food, Agricultural, and Environmental Sciences at Ohio State. “Lycopene, the primary carotenoid in tomatoes, has been shown to be the most effective antioxidant of these pigments,” she says in a news release.

“However, when comparing lycopene administered from a whole food (tomato) or a synthesized supplement, tomatoes appear more effective in preventing redness after UV exposure, suggesting other compounds in tomatoes may also be at play.” 

In the new study, the Ohio State researchers found that only male mice fed dehydrated red tomatoes had reductions in tumor growth. Those fed diets with tangerine tomatoes, which have been shown to be higher in bioavailable lycopene in previous research, had fewer tumors than the control group, but the difference was not statistically significant.

Cooperstone is currently researching tomato compounds other than lycopene that may impart health benefits.

The three-year study was supported by the National Institutes of Health through the National Cancer Institute. Other Ohio State researchers who worked on the study were David Francis, professor in the Department of Horticulture and Crop Science; and Steven Schwartz, a professor in Food Science and Technology.