The lettuce is a very popular vegetable which is cultivated for its large leaves; in some cases, these are pressed forming more or less compact core or heart. There are many varieties of this vegetable, and their number increases every year. The nutritious properties of this plant are scarce, although it is low in calories and supplies some vitamins and minerals.
The lettuce is composed of large overlapped leaves, forming in some cases a sprouting. There are lettuces of different shape, size and colour, either green or red. They may have more or less sawed leaves.
There exist multiple varieties of lettuce and every year some new ones are obtained, offering significant improvements as far as production, shape of the heart or resistance to diseases. Some of the most known types are the Roman lettuces, Iceberg, trocadero, etc. New groups like the baby lettuces or the red lettuces have also appeared in the market.
The lettuce is eaten raw, in salads together with tomato and onion, among some other ingredients. It can also be eaten cooked or roasted, although less frequently. It is also consumed in vegetable stews.
It has a low content of nutrients and fat, making it recommendable in slimming diets. It gives some vitamins, like vitamin C and folic acid, and small quantities of phosphorus, potassium, iron and calcium. It is considered to have tranquillizer and sedative properties.