Lycopene

Lycopene is a carotenoid, specifically a tetraterpene hydrocarbon built from eight isoprene units, with the formula C40H56. Its chain of eleven conjugated double bonds absorbs light in a way that produces its deep red color and also makes it a strong antioxidant. It is fat-soluble and insoluble in water, so its absorption depends on dietary fat and bile. Plants make lycopene in the all-trans configuration, but exposure to heat and light converts some of it into cis-isomers, and in human blood these cis-forms actually make up the majority of circulating lycopene.

The richest dietary sources are tomatoes and tomato products, along with watermelon, pink grapefruit, guava, and the gac fruit. A notable feature is that processing improves availability: cooking and concentrating tomatoes, as in paste or sauce, and eating them with oil substantially increase how much lycopene the body can absorb, and oil-based supplements are absorbed efficiently as well.

Much of the health interest in lycopene stems from its antioxidant behavior. An umbrella review of existing meta-analyses reported that higher tomato or lycopene intake was inversely associated with several outcomes, including all-cause mortality, prostate cancer, stroke, and cardiovascular disease, while cautioning that the underlying evidence was mostly of low or very low quality ^[1]. In prostate cancer specifically, pooled analyses of randomized trials found that lycopene supplements did not significantly change prostate-specific antigen levels overall ^[2][3], although one analysis noted a reduction among men who began with higher baseline levels ^[3]. On balance, a protective effect remains unproven in controlled research.

Lycopene is approved as the food colorant E160d in the European Union and is used as a color and supplement ingredient elsewhere, typically in oil-based softgels. It is considered non-toxic; very high intake can cause lycopenemia, a harmless orange discoloration of the skin that fades once intake is reduced.

Lycopene is very safe; high intakes can cause a harmless orange skin tint (lycopenodermia). No serious interactions are established. It is considered safe as both food and supplement.