Colour on the plate: what fruit and vegetables actually do
"Eat more fruit and vegetables" is advice so worn out that it has stopped meaning anything. It is worth explaining what the colours are actually doing, because the reasoning is more interesting than the slogan. Colour is a chemical signal The colour of a plant is produced by the compounds it makes to protect itself — from sunlight, from insects, from oxidation. Those compounds are the reason a red pepper is red, and they are largely what we are after when we eat it. Because different pigments do different jobs, variety of colour is a decent proxy for variety of compound. That is the whole basis of the "eat the rainbow" advice, and it is a better rule of thumb than counting portions of the same green salad. Red — tomatoes, watermelon, pink grapefruit. Lycopene, the carotenoid most often studied in relation to the prostate. It is fat-soluble and is absorbed better from cooked tomatoes with a little oil than from raw ones. Tomato sauce beats salad here, which ...