Tomatoes are low in calories and are packed with nutrition, especially when they are fully ripe. For example, red tomatoes contain up to four times the amount of beta-carotene as green tomatoes. Tomatoes provide an excellent source of vitamins C and K, carotenes (especially lycopene), and biotin. They are also a very good source of vitamin B6, niacin, folic acid, fiber, and pantothenic acid.
Due to the high content of lycopene that tomatoes contain,they have increasingly received a lot of attention as a health food. Studies have shown that the red carotene (lycopene) is extremely protective against breast, lung, colon, prostate, and skin cancers. Studies also found that tomatoes lower the risk of heart disease, cataracts, and macular degeneration. The way lycopene works, is it helps to prevent those diseases and others by neutralizing harmful oxygen free radicals before they can do any damage to cellular structures.