Are legumes the protein-source of the future?
The UN (United Nations) has declared 2016 the International Year of Pulses. They are considered a good alternative to meat, with benefits to health, for animals and for the environment, and therefore looked upon as the preferred protein-source of the future. Pulses were also considered as “the poor man’s meat”, because they were usually eaten by people who could not afford meat, but actually they are not good meat substitutes.
Legumes contain 3-times less proteins than meat, gram for gram, and these proteins are neither high quality nor easily absorbed. During an interview we have made to nutritionist Elisabetta Bernardi, she explained:
“The risk of trying to get the proper amount of essential amino acids from an exclusively fruit and vegetable diet is to introduce, at the same time, other nutrients in greater amounts than needed. The combination of cereals and legumes is often indicated as an adequate meat substitute because of its protein count, since cereals´ deficiencies in essential amino acids are covered by crops´ essential amino acids and vice versa. But to get the same amount of amino acids cointained in 70 grams of meat, which is equal to a small slice that provides less than 80 kcal, we should eat 2 portions of pasta with beans, with an intake of more than 700 kcal. It is advised to keep this in mind, especially with today’s high rate of obesity “.
150 years ago the population was undernourished. The main affordable foods in Italy were pasta, legumes and seasonal vegetables. This extreme poverty caused severe malnutrition and only few privileged people could afford meat. In fact, legumes contain anti-nutrients that cannot be turned off completely even by cooking and soaking. In some cases, some of the anti-nutritional factors can be removed with a long cooking time but this method leads also to protein denaturation.
For example, the dangerous saponins, anti-nutrients that cause the increase in intestinal permeability, allowing toxins and bacteria to interact with the immune system and increasing the risk of heart disease and cancer, cannot be turned off even after 2 hours of cooking, while they are inhibited by fermentation process.
The same goes for phytates, compounds that inhibit the absorption of important minerals, such as iron, zinc, calcium and magnesium, causing nutritional deficiencies. Phytates can be deactivated by fermentation and germination processes. Thanks to the economic growth, the population was able to have more and easier access to foods with higher nutritional value, such as animal source food, and therefore living conditions greatly improved.
Thanks to animal proteins, Italians were able to achieve their best genetic potential, even increasing height. We are among the longest-living people, thanks to the Mediterranean Diet, which includes also meat, fish, milk and dairy products.
In the future, meat could again become less affordable and just for privileged people because we are going to be too many on Earth, but replacing completely meat with legumes is not “future”, it is just a return to the past that could cause again the same nutritional deficiencies the population had 150 years ago.
Legumes are totally excluded from Paleo diet-supporters, because considered highly toxic. I would not consider them so badly, because they also have many important positive features. The important thing is to have a balanced and varied diet, as our Mediterranean Diet suggests, not excluding any food and in which legumes play a fundamental role.
Susanna Bramante is an agronomist and scientific writer, author and co-author of 11 scientific publications and numerous articles on human nutrition and its impact on health and environment. In 2010 she received the title of Doctor Europaeus and PhD in Animal Production, Health and Food Hygiene in countries with a Mediterranean climate.