Lycopene
Carotenoids
The red of tomato and watermelon.
It is the rare case where cooked beats raw: heat and oil multiply its absorption. It is a pigment, so it follows the color: pink grapefruit carries it, white does not — hence two catalog entries.
Effects and benefits
The red of tomatoes is more useful cooked than raw, and the skin remembers it: in trials, tomato paste every day made it less sensitive to sunburn, without replacing sunscreen. The body stores it in unexpected places, including the prostate.
In a raw tomato, lycopene is locked in crystals inside the cells. Cooking breaks the walls and oil dissolves it: a sauce or paste gets two to three times more into the blood than the same raw tomato (Gärtner et al., 1997).
In trials of ten to twelve weeks, 40 to 55 g of tomato paste a day reduced the redness caused by UV in the laboratory, by 40% in one of them (Stahl et al., 2001; Rizwan et al., 2011). It is a modest background protection, not a sunscreen.
The body concentrates it in a few organs: the skin, the liver, the adrenal glands and, in men, the prostate. Observational studies associate frequent tomato sauce with a lower risk of prostate cancer (Giovannucci et al., 2002); trials have not confirmed an effect of lycopene itself.
Sources: Gärtner et al., AJCN, 1997 · Stahl et al., J Nutr, 2001 · Rizwan et al., Br J Dermatol, 2011 · Giovannucci et al., JNCI, 2002