Tomatoes and Lycopene: a Review of the Science

February 3, 2017
By: Kathleen Walters

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Tomatoes are a versatile vegetable with an endless number of uses in the kitchen. They also offer an array health benefits that may aid in the prevention of disease.  Research suggests that consuming tomatoes (and tomato products) is associated with a decreased incidence of cardiovascular disease and reduced risk of prostate, lung, breast, and digestive cancers. These health benefits are derived mainly from the lycopene, vitamin C, and quercetin found in tomatoes.  Each of these bioactive food components has important mechanisms of action that make tomatoes a nutrition powerhouse, but lycopene is particularly touted for its powerful effects!

Lycopene and Cancer Prevention

Lycopene is a type of carotenoid that provides the taste and red color of tomatoes.  Among the family of carotenoid pigments, lycopene’s claim to fame is having the greatest antioxidant potential. Research using in vivo animal cancer models shows lycopene can inhibit prostate, breast, and lung cancer growth by demethylating promoter DNA tumor suppressor genes. By reducing the formation of DNA oxidation products, lycopene prevents the DNA damage and abnormal cell development associated with tumors. Lycopene may also interfere with the production of insulin-like growth factor 1 (IGF-1), a protein associated with cancer cell growth.

Lycopene also helps decrease prostate cancer progression. Prostate cancer patients who supplemented their diets with lycopene showed reduced IGF-1 plasma levels by almost 30%. Lycopene also helps maintain proper gap junction communications (GJC) between cells. Since tumor cells don’t have GJCs that function correctly, lycopene corrects the dysfunctional GJCs, reducing the risk of prostate cancer progression.

Lycopene: Protecting the Heart and Busting Fat

In addition to protecting against cancer, lycopene is important in preventing cardiovascular disease and obesity.  Lycopene is inversely associated with the thickness of blood vessel inner walls, calcified plaques in the abdominal aorta, and LDL oxidative damage, all of which are markers of atherosclerosis. Lycopene also suppresses visceral fat accumulation and increases brown adipose tissue (BAT) weight. Since BAT helps to increase thermogenesis and thereby increase oxidation of lipids as opposed to storing lipids, this can help to fight against obesity.

Bioavailability of Lycopene in Foods

The way in which tomatoes are processed affects the bioavailability of lycopene. Lycopene is easier to absorb when its compounds are in the cis configuration, due to the increased solubility of the cis-isomer in bile acid micelles. Food processing can increase the cis-isomer formation, making heating and cooking great options for food preparation. Tomato products with the highest amount of lycopene include tomato paste, ketchup, tomato sauce, and spaghetti sauce.

Although a specific amount of lycopene has not been recommended for daily consumption, recent research has shown that as little as 27 mg of lycopene per day may reduce inflammatory markers related to cardiovascular disease. Whether consumed as a tasty sauce with whole-grain spaghetti or diced and sautéed with a bowl of lentils, there are countless ways to obtain the great benefits of this important food component.