The family to which legumes belong, named Fabaceae, once known only as Leguminosae, is very large (for example also licorice and mimosa belong to it), and the species cultivated with edible seeds are about sixty.
Legumes have become part of the Mediterranean diet in ancient times, imported over the centuries from the Nile Valley, the Far East and later from the Americas. The Etruscans ate the species still known as cowpea.
Even the taverns of ancient Rome served beans, which apparently were not considered a delicious food: distinguishing it from peas, lentils and broad beans, Virgil referred to beans as "Vilem phaseulum".
Today, the most common legumes are the species originating from America: white beans, kidney beans, Spanish beans, black beans, Mexican beans, red kidney beans. Chickpeas come from the Middle East and India; peas instead seem to have originated from the south east of the Mediterranean basin, as well as lupins and grass-peas.
Lentils instead have uncertain origins, in the ancient times they were already eaten both in India and in South America; for centuries, they were one of the first foods cultivated and eaten by humans.
Even peanuts, tamarind and soybean, the latter originated in Japan and China, are legumes. Beans were called "poor man's meat" because until the mid-twentieth century, when meat was still a scarce and precious commodity, legumes were the main source of protein, especially for people who, living far from the sea, could not take advantage of fishing.
The proteins of legumes are not as complete as those of meat, fish, milk and dairy products, which instead have all nine essential amino acids. For this reason, even without any knowledge of biochemistry, our ancestors used to eat beans together with spelt grains, then with pasta and rice.
In fact by combining legumes and grains it is possible to obtain good quality proteins, similar to those of animal origin.
Even today eating at least three times a week typical dishes such as pasta and beans, rice and peas, pasta and chickpeas, is a great option to alternate the consumption of meat and eggs.
The nutritional properties of legumes are several.
The percentage of protein in legumes is far greater than in other plant species (in dried pulses the amount ranges from 21% of chickpeas to 23% of lentils), but they also offer slow release carbohydrates such as those of cereals, then energy: 100 grams of pulses have an average 50% of carbohydrates content.
Thanks to the high percentage of fibers, this non-nutrient promotes the sense of satiety and is essential to facilitate bowel movement and to reduce the risk of colon disorders and constipation.
Many other health beneficial substances are contained in legumes, such as vitamins B1 and PP and minerals such as iron and calcium. But vitamins are water soluble and are lost with cooking, which in turn is necessary to make digestible the alkaloid substances often present in raw legumes. This is not the case for fava beans, which can also be eaten uncooked: together with pecorino they form a delicious dish very popular in central Italy.
Peanuts and soybeans provide nutrients in very different amounts compared to the majority of the Fabaceae: they provide fewer carbohydrates, but much more proteins and polyunsaturated and monounsaturated fats, also known as good fats.
Soybeans (dry legume) contain 37% of proteins and 19% of lipids; roasted peanuts contain 29% of proteins and 49% lipids.
In general, "traditional" legumes contain very little fats: from 6% in chickpeas up to 1-3% of beans, fava beans, lentils and peas.
Lipids (including omega-3 polyunsaturated fats also present in dried shelled fruit) contained in soybeans, and lecithin are essential nutrients very useful for our health because they are involved in many metabolic activities, act against cholesterol and reduce the risk of cardiovascular diseases.
One of the factors that makes the Mediterranean diet the one that protects health more than any other diet is specifically the presence of mono and polyunsaturated fats of which fish, and olive oil are rich along with almonds and walnuts whose good fat content is similar to that of peanuts.
The contents of this article are in accordance with the parameters set out by the European Food Safety Authority - EFSA.