Tomatoes the Cancer Fighting Superfood
The once humble tomato is now being recognized as one of the most important superfoods.
The power behind the value of the tomato is lycopene.
Scientific studies show that lycopene helps prevent prostate, lung, and stomach cancers.3 There is also some evidence that cancers of the pancreas, colon and rectum, esophagus, oral cavity, breast, and cervix could be reduced with increased lycopene intake.3 This hearty antioxidant provides a two-for-the-price-of-one deal as it may help reduce your risk of developing cardiovascular disease by reducing LDL (“bad”) cholesterol and lowering blood pressure.
Fruits and vegetables that are high in lycopene include autumn olive, gac, tomatoes, watermelon, pink grapefruit, pink guava, papaya, seabuckthorn, wolfberry (goji, a berry relative of tomato), and rosehip. Although gac (Momordica cochinchinensis Spreng) has the highest content of lycopene of any known fruit or vegetable, up to 70 times more than tomatoes for example, due to gac’s rarity outside its native region of southeast Asia, tomatoes and tomato-based sauces, juices, and ketchup account for more than 85% of the dietary intake of lycopene for most people. The lycopene content of tomatoes depends on species and increases as the fruit ripens.
Unlike other fruits and vegetables, where nutritional content such as vitamin C is diminished upon cooking, processing of tomatoes increases the concentration of bioavailable lycopene. Lycopene in tomato paste is up to four times more bioavailable than in fresh tomatoes.
While most green leafy vegetables and other sources of lycopene are low in fats and oils, lycopene is insoluble in water and is tightly bound to vegetable fiber. Processed tomato products such as pasteurized tomato juice, soup, sauce, and ketchup contain the highest concentrations of bioavailable lycopene from tomato-based sources.
Cooking and crushing tomatoes (as in the canning process) and serving in oil-rich dishes (such as spaghetti sauce or pizza) greatly increases assimilation from the digestive tract into the bloodstream. Lycopene is fat-soluble, so the oil is said to help absorption. Gac is a notable exception, containing high concentrations of lycopene and also saturated and unsaturated fatty acids.
Lycopene may be obtained from vegetables and fruits such as the tomato, but another source of lycopene is the fungus Blakeslea trispora. Gac is a possible commercial source of lycopene for the purposes of extraction and purification, as its seed content of lycopene is high.
The cis-lycopene from some varieties of tomato is more bioavailable.
Note that there are some resources which make the mistaken assumption that all red fruits contain lycopene, when in fact many are pigmented by other chemicals. An example is the blood orange, which is colored by anthocyanins, while other red colored oranges, such as the Cara cara navel, and other citrus fruit, such as pink grapefruit, are colored by lycopene.
In addition, some foods that do not appear red also contain lycopene, e.g., asparagus, which contains approximately 30μg of lycopene per 100 gram serving (0.3μg/g) and dried parsley and basil, which contain approximately 3.5-7 μg of lycopene per gram.