Like the potato, the tomato was unknown to the world at large until the colonisation of the Americas in the 16th century, although from its prominence as a sauce ingredient it might be expected to go back to the Romans. Now grown worldwide, the tomato is a ubiquitous fruit that thinks it is a vegetable, and appears in all sorts of salads, sauces, condiments and drinks, and as a favourite soup.
Being 95% composed of water, the nutritional content of a tomato is fairly low, although its colour indicates a high vitamin A carotenoid content, and it has a reasonable amount of vitamin C, some vitamin E and K as well as B complex vitamins, together with potassium, magnesium, manganese and phosphorus.
The vitamin A carotenoids have been demonstrated to help prevent age-related macular degeneration, which can lead to cataracts and blindness. Vitamin C is important in maintaining healthy skin, while vitamin E is a powerful antioxidant which helps combat cell-damaging free radicals, and vitamin K is necessary for blood coagulation.
Tomatoes also contain a significant quantity of lycopene; some studies have shown lycopene to possess antioxidant effects, and it may also be effective in blocking the growth of invasive cells.