Daily consumption of tomatoes reduced the number of skin cancer tumors by half in male mice, according to a 2017 study completed at Ohio State University.
What the research shows
Researchers used mice to test the theory that tomatoes can help reduce the risk of skin cancer. The mice in the study were given one of three diets: a control (non-tomato) diet, a diet containing tangerine tomatoes, or one with red tomatoes. The mice were then exposed to ultraviolet light. The male mice who received the red tomato diet had an average of 50 percent fewer tumors than the control group at the end of the 35-week study. The mice given tangerine tomatoes also had a significant reduction of tumors, but not quite as much as the mice given a diet of red tomatoes.
Why tomatoes lessen the risk of skin cancer
The researchers believe that carotenoids, which are the pigmenting compounds that give tomatoes their color, help protect the skin from damage from UV rays. Lycopene, which is the primary carotenoid, is an antioxidant which can have protective properties. However, the researchers noted that there was a difference in protection when using tomatoes as a whole food and using a supplement. This, they believe, shows there is more than just lycopene at work and that other compounds in the tomato contribute to the protective properties of the food.
One important take-away of the study is that prevention and protective methods might be different depending on gender. The female mice in the study did not show any significant reduction in skin cancer tumors. But the authors note that previous studies have found that male mice “develop tumors earlier, and these tumors are more numerous, larger and more aggressive than in female mice.”
You still need to practice sun safety
Eating tomatoes and tomato products, such as tomato paste, might help protect you from skin damage, but just doing so isn’t enough. Practicing sun safety by applying sunscreen every day, wearing a wide-brimmed hat and avoiding prolonged exposure to direct sunlight between 10:00 a.m. and 4:00 p.m. is important. Jessica L. Cooperstone, co-author of the Ohio State study, indicates that certain foods might help to decrease the risk, but they are not the only method you should use.
Other health benefits of tomatoes
Tomatoes provide a number of health benefits. They are high in fiber and a good source of vitamin A, C, and B2 and potassium. They contain lycopene and beta-carotene, which are both thought to help reduce or prevent chronic disease.
- Lycopene is thought to reduce the risk of heart disease, according to a review of studies published in 2011 in Current Medicinal Chemistry.
- Tomatoes were one of the most effective foods in reducing blood clotting and blood vessel blockages, according to a study also published in 2011 in Blood Coagulation Fibrinolysis.
- High levels of vitamin C, which is plentiful in tomatoes, was found to lower the risk of developing heart disease, according to a study published in 2015 in the American Journal of Clinical Nutrition.
- Alpha-tomatine, a phytonutrient in tomatoes, was found to be helpful in fighting prostate cancer, as reported in a study published in 2011 in PloS One and in fighting lung cancer, as reported in a study also published that year in Cell Biochemistry and Biophysics.
- Lycopene may lower the risk of stomach cancer, according to a study published in 2015 in the Journal of Cancer Prevention.
- Lycopene may decrease the risk of stroke in men, as reported in 2012 in Neurology.
Tomatoes can be enjoyed fresh or cooked. When cooked into tomato paste or used in products such as ketchup, the concentration of lycopene is higher. However, eating tomatoes fresh still offers many health benefits.
Note, however, that for some people, the high acidic level of tomatoes can cause indigestion and eating excess lycopene daily can cause nausea, diarrhea, indigestion, or flatulence, according to a 2007 study in Urology. People who need to watch their dietary intake of potassium, such as those with kidney disease, should talk to a doctor about how much tomato they should include in their diet.