Along with dairy products, soy is one of the thorniest topics in nutrition. For several years, scientists have been crunching their buns with studies that, each time they appear in scientific journals, cause controversy. Some studies encourage people to consume it as it would be good for health, cardiac in particular. Others accuse her, due to its high content of phytoestrogens (or isoflavones), of interfering with female hormones, hence her sulphurous reputation as "endocrine disruptor". An argument not trivial when we know that women are the biggest consumers of soy foods.
Soy: is it a cereal or a legume?
The soybean plant resembles that of beans and is part of the same family, that of legumes, the fruit of which is a green pod. These are the pods that contain the famous seeds used to produce soy juice, tofu, vegetable steaks and other derived foods. Not to be confused with "soy sprouts", served in particular in Asian restaurants, which are sprouted mung bean seeds which belong to a family of plants (fabaceae). These can be eaten raw while the soybeans must be cooked before consumption. In her book "Planète Soja" (edition of Le Rocher), Julie Lotz specifies that "In 2016, the Directorate General for Consumption, Competition and the Fight against Fraud (DGCCRF) ruled: mung beans will now have to be marketed without any reference to soybeans. They can therefore no longer be called and sold under the 'appellation soy sprouts ".
What are the benefits of soy?
In a recent press release (April 30, 2020), the company Sojaxa (a collective of companies like Alpro, Sojasun, Soy which market soy products from French cultures) highlights the virtues of soy foods for health citing several studies that tend to prove that their consumption lowers cholesterol and blood pressure, which reduces the risk of stroke and myocardial infarction. The press release also recalls that the Food and Drug Administration (FDA) authorizes since 1999, in the USA, the allegation "soy can reduce cardiovascular risk" and that a meta-analysis (which combines the results of several studies) published in June 2019 in the "Journal of The American Heart Association" concluded that the recommendations of the American agency on the intake of soy consumption for cardiovascular health remains topical. However, according to the FDA, the maximum dose not to be exceeded (0.3 mg of phytoestrogens per kilogram of body weight per day) is lower than in France (1 mg). Another study, published in 2019 in the journal "Circulation" confirms that it is better to replace red meat with high-quality protein sources from plants, such as soy foods, other legumes or nuts, in the goal of controlling your blood lipid and lipoprotein levels. "In practice, explained in the Sojaxa press release, Dr. Corinne Chicheportiche-Ayache, nutritionist, 25 g of soy protein this represents a 150 ml glass of soy juice, 100 g of tofu and a soy dessert of 100 g also, or almost the equivalent of a chicken breast of 100g ".
Is soy bad for your health?
Difficult to pronounce because of the lack of consensus between scientists! For anti-soy, the problem comes from the isoflavones it contains. According to Pr Catherine Bennetau-Pelissero, main whistleblower on the harmful effects of the plant: "If you drink a liter of soy juice in two hours, you will start your period at night". Journalist Julie Lotz has experienced this and she says in her book that she suffered from "unusual menstrual pain". Professor Bennetau-Pelissero assures him: "Drinking soy juice in less than two hours has created an estrogen spike similar to the one that occurs naturally in the body of women before menstruation arrives". Moreover, several studies cited in the journalist's investigation indicate that these soy isoflavones can have an impact on the female cycle (and even on male fertility!). In one of them, it is even specified that "45 mg of isoflavones (a soy steak) have an impact on the menstrual cycle". For its part, in 2005, the French National Health Security Agency (ANSES) advised against their consumption by pregnant women because, "consumed during pregnancy, they can increase the risk of testicular and breast cancer in the unborn child".
How much soy can we eat per day?
In 2005, ANSES recommended not to exceed 1 mg of isoflavones per kilogram of body weight per day. Thus, a 60-pound woman should limit herself to 60 mg per day: either a steak and a glass of soy juice. Faced with uncertainty, some nutritionists go further by invoking the precautionary principle. Thus Véronique Beck, author of "Reducing the meat" (Jouvence edition) proposes to vary the sources of vegetable proteins by alternating tofu, tempeh or miso etc … and pulses, cereals, oilseeds, seeds, while not consuming soy foods more than once a week, and not more than 80mg of isoflavones, two servings. For example 100g of tofu plus 1 soy dessert. Another warning from ANSES concerns toddlers. In the "EATinfantile" study, published at the end of 2016, experts estimated that children under 3 who consume soy-based foods have intakes of phytoestrogens of concern. At the time, Professor Catherine Bennetau-Pelissero, advanced in the pages of Current Woman "that it is possible that the regular consumption of infant milks containing soy or juice and soy “yogurts”, once started the food diversification, exposes the children to anomalies of the sexual organs and difficulties in having children when they will be adults ".
What are the benefits of soy milk?
Recall that talking about soy "milk" has become inappropriate. Since 2017, a European regulation stipulates that it is necessary to say "soy juice". Today, soy drinks are more varied and greedy, some are sweetened with fruit juice or sugar, others are flavored or mixed with almonds … In practice, soy juice can replace the cow's milk in all its uses: in drink, on oat flakes or corn petals, to prepare sauces or desserts … Its advantage: like other vegetable drinks, the juice extracted from soya beans is a alternative for those who ban animal feed sources and those intolerant to lactose (milk sugar) or casein (one of the milk proteins). Close to cow's milk in terms of the amount of protein: 3.28g / 100g versus 2.96g / 100g for the juice (source Ciqual), it contains neither saturated fatty acids nor cholesterol. Its weak point: no calcium. If it is consumed regularly as a replacement for dairy products, nutritionists advise opting for calcium-enriched soy juices. Be aware that it also contains these famous controversial isoflavones.
How to consume soybeans?
In addition to its drink version, soy can be consumed in several ways.
- Roasted soybeans: they peck as an aperitif like peanuts.
- Soy flakes: they can be used in savory or sweet preparations (soups, cakes, pancakes …).
- Vegetable steaks: they look like pancakes that you can cook in the pan or slide into a burger. Reputed to be healthier than meat, they often contain too much salt and a lot of additives. So read the labels carefully.
- Tofu: plain and tasteless, you have to mix it with vegetables and add herbs, spices, seeds, dried seaweed … Smoked, it comes in a block to be cut into matches, cubes … to replace bacon for example. Silky, its soft texture makes it possible to make desserts (tiramisu, cheesecake) or sauces.
- Tempeh: Originally from Indonesia, this fermented soybean product has a spongy texture and an earthy taste, with aromas of mushroom and hazelnut. It is found in the form of a block: plain, with algae, with cereals, legumes. It can be added to soups or make sauces, or cooked in Bolognese to replace meat in lasagna, mince or pasta.
- Miso: brownish and quite thick, this fermented soybean paste is a Japanese specialty. The ideal is to choose an unpasteurized and organic miso. Its taste is particular, very pronounced. The darker it is, the more salty it is. It should not be cooked but added at the end of cooking in a broth, a velouté. It is also used as a condiment in marinades of meat or fish, in sauces and in desserts.
- Textured soy proteins: ready to simmer in vegetarian dishes, they come from de-oiled soybeans and ground into flour and come in the form of minced, small or large pieces … Neutral flavor, you have to add spices, herbs, herbs. Now, they can be purchased in supermarkets (Leclerc, Intermarché, etc.).
Read also :
⋙ Soy: a false friend for women's health?
⋙ Tofu, miso, tempeh … what are all these soy derivatives?
⋙ 15 sources of vegetable protein that help keep you in shape