Skin cancer is the most common form of cancer in the U.S., affecting one out of every five Americans, and its incidence is rising. Ultraviolet (UV) radiation is responsible for the development of most skin cancers and also skin aging. 
Ultraviolet radiation from the sun exerts these aging and carcinogenic effects on the skin via oxidative stress, inflammation, and damage to DNA. As such, there has been much interest in the scientific community in using antioxidants from plant foods to protect against this damage. Photoprotection has been previously demonstrated in animal studies by multiple antioxidant supplements, including green tea catechins, proanthocyanadins, resveratrol, and silymarin. In addition to their antioxidant effects, these substances can also absorb UV radiation (when applied topically), enable DNA damage repair, and reduce inflammation. 
Lycopene, well-known for its prostate cancer-protective effects, is a carotenoid antioxidant present in red and pink fruits such as tomato, grapefruit, and papaya. It is especially concentrated in cooked tomato products like tomato paste. Lycopene is a powerful antioxidant that in vitro has been shown to prevent or repair damage to DNA that potentially leads to cancer development. Lycopene also stimulates production of antioxidant enzymes, inhibits signals that promote tumor progression, and promotes programmed death of cancerous cells. 
Researchers tested whether the antioxidant actions of lycopene in tomato paste could lessen the skin-damaging effects of UV radiation in human subjects. A group of healthy women consumed tomato paste daily for twelve weeks, and their skin’s reddening response to UV light was measured at the beginning and end of the study. After twelve weeks of tomato supplementation, the skin’s resistance to UV-induced reddening was enhanced. The tomato paste supplementation also resulted in reduced mitochondrial DNA damage and reduced activity of an enzyme that degrades the skin’s extracellular proteins, a process that contributes to skin aging. These results suggest that regular tomato consumption can help to reduce the skin-damaging effects of the sun. 
Tomatoes are rich not only in lycopene but in thousands of other protective compounds, both discovered and undiscovered, that likely have powerful heart disease- and cancer-preventive effects. Be sure to eat both fresh, raw tomatoes and cooked tomatoes to get the full spectrum of tomatoes’ phytochemicals.
1. Skin Cancer Foundation: Skin Cancer Facts. October 14, 2010]; Available from: http://www.skincancer.org/Skin-Cancer-Facts/.
2. Nichols, J.A. and S.K. Katiyar, Skin photoprotection by natural polyphenols: anti-inflammatory, antioxidant and DNA repair mechanisms. Arch Dermatol Res, 2010. 302(2): p. 71-83.
3. van Breemen, R.B. and N. Pajkovic, Multitargeted therapy of cancer by lycopene. Cancer Lett, 2008. 269(2): p. 339-51.
4. Rizwan, M., et al., Tomato paste rich in lycopene protects against cutaneous photodamage in humans in vivo. Br J Dermatol, 2010.