Lycopene in Tomatoes

The phytochemical lycopene can be found in tomatoes and has been linked to a wide range of potential health benefits. While the specific biological activity of lycopene in tomatoes remains under investigation, this compound does seem to contribute heavily to tomatoes' status as a healthy, nutritious food. Even more exciting is evidence that cooking and processing can improve the lycopene content of tomatoes, thus increasing the beneficial properties of common foods such as pizza sauce and ketchup.

Lycopene

Lycopene belongs to the group of phytochemicals called carotenoids, a group that also contains alpha-carotene, beta-carotene, beta-cryptoxanthin, zeaxanthin and lutein. While many carotenoids are precursors to vitamin A, lycopene is a different type of carotenoid. Because of the high levels of consumption of tomato products, including ketchup, pizza and tomato soup, many people in the U.S. consume this phytochemical in high amounts.

Tomatoes

Tomatoes are the most concentrated food source of lycopene, containing 4.6 mg per cup. Other foods, such as watermelon and red papaya, contain far lower levels of this phytochemical. Lycopene gives tomatoes their bright red color, so yellow tomatoes and tomatoes that are lighter in color may not contain significant levels. Not only are tomatoes a healthy source of lycopene, they are safe to eat, even in large amounts.

Processing

Processed tomatoes often contain more lycopene than raw tomatoes. Canned tomato paste has 4.6 mg per tbsp., or about 48.9 mg per 6-oz. can. A cup of tomato sauce contains 34.2 mg of lycopene. One tbsp. of ketchup has 2.5 mg of lycopene. There are 24.8 mg of lycopene in a cup of sun-dried tomatoes. Tomatoes cooked for 15 minutes have 171 percent more lycopene than raw tomatoes, according to Science News. Cooking tomatoes in oil or another type of fat can also increase the availability of lycopene. Consuming cooked tomatoes results in higher levels of lycopene in the blood than consuming raw tomatoes.

Health Benefits

Lycopene is an antioxidant that acts to block free radicals in the cell. Other potential health benefits include protection against prostate, lung and stomach cancer, macular degeneration and cardiovascular disease, but these effects remain under study. A meta-analysis published in the March 2004 issue of the journal "Cancer Epidemiology Biomarkers and Prevention" found a modest reduction in prostate cancer risk for men who consumed higher levels of tomatoes or tomato products. Some other studies have shown mixed results, however, so the evidence for lycopene activity against cancer is still not definitive.

References

• Linus Pauling Institute: Carotenoids
• USDA National Nutrient Database
• "Cancer Epidemiology Biomarkers and Prevention" : The role of tomato products and lycopene in the prevention of prostate cancer: a meta-analysis of observational studies.
• Science Daily: Cooking Tomatoes Boosts Disease-Fighting Power
• American Cancer Society: Lycopene