BENEFITS OF SOY
✓ Source of plant-based proteins
✓ Reduces cholesterol
✓ Supports bone health
✓ Improves menopause symptoms
✓ Protects the heart
What is soy?
Like the lupin, lentils or the fenugreek, soy (Glycine max) is a legume of the Fabaceae family. Reaching up to 1.30 m in height, it produces hairy pods that contain up to 4 seeds. These are the ones that are harvested, eaten as is or processed.
Originally from Asia, it is believed to have been cultivated for the first time in China, 3,000 to 5,000 years ago. Gradually, the plant was introduced to Japan, Europe, and then the United States, which is today the world’s leading producer.
Soy consumption made a real comeback in the 1990s. Promoted as a healthy, nutritious food, it appeals to people concerned about their health and looking to reduce or eliminate their meat consumption.
It is one of the best-known alternatives for replacing meat in a vegetarian or vegan diet. Indeed, it has a high content of plant-based proteins and contains all the essential amino acids. Soybeans also contain fiber, fatty acids, vitamins, minerals and trace elements.
Widely studied, it offers numerous health benefits. In addition to being an excellent source of protein, it lowers cholesterol, supports bone health and improves menopause symptoms. It is also recognized for its cardioprotective effect.
Soy now ranks 7th among the world’s main agricultural productions. About 70 % of production is destined for animal feed and processed into soybean meal. In recent years it has experienced a phenomenal growth, particularly in South America. Unfortunately, this development has a heavy impact on the environment : with palm oil, soy contributes greatly to deforestation, which is why it’s important to carefully control its sourcing.
Nutritional composition
- 18 acides aminés
- Vitamines : pro-vitamine A, B1, B2, B3, B5, B6, B8, B9, E, K
- Minéraux et oligo-éléments : calcium, chlore, cuivre, fer, magnésium, manganèse, phosphore, potassium, sodium, zinc
- Lipides
- Protéines
- Glucides
- Fibres
- Acides gras : oméga 3-6-9
- Actifs antioxydants : isoflavones
The benefits of soy
🌿 Source of plant-based proteins
With 38 g per 100 g, soy is among the best sources of plant-based proteins. It is therefore a very useful food for reducing or even eliminating animal proteins from one’s diet.
The proteins it contains also have the advantage of being complete, meaning they contain all the essential amino acids for the human body. They notably include valine, phenylalanine, leucine and the precious tryptophan.
Cette revue de la Loyola University Chicago Stritch School of Medicine (États-Unis) a étudié la composition du soja et sa teneur en protéines.
Lire aussi l Nos conseils pour acheter des protéines végétales
🍳 Reduces cholesterol
Soy helps lower blood cholesterol levels. It notably reduces LDL cholesterol (or “bad cholesterol”) which deposits on the vessel walls and leads to arterial blockage.
This action is largely due to the isoflavones it contains. In addition to fighting free radicals, these molecules lower blood lipid levels, including cholesterol and triglycerides.
This study from the National Institute of Health and Nutrition in Tokyo (Japan), conducted in humans, shows the benefits of soy on cholesterol levels.
🦴 Supports bone health
Soy isoflavones also have a beneficial effect on bone health. Thus, they improve bone mineral density (BMD) and bone remodeling for strong, resilient bones. This legume is particularly studied as a potential agent in the prevention and treatment of osteoporosis, a skeletal disease related to aging.
This study by the National Institute of Health and Nutrition in Tokyo (Japan), conducted in postmenopausal women, shows how soy can prevent osteoporosis and improve bone strength.
🌺 Improves menopause symptoms
Soy isoflavones are not only antioxidants. They are also natural phytoestrogens and have effects similar to female hormones (estrogens).
This legume contains three major isoflavones called genistein, daidzein and glycitein. They help raise the level of estrogens that drops at menopause and reduce symptoms associated with hormonal changes such as hot flashes.
This study from the University of Ferrara (Italy), conducted in postmenopausal women, shows how soy reduces the frequency of hot flashes.
❤️ Protects the heart
Soy has a beneficial effect on the heart. On the one hand, it limits cardiovascular risk factors such as hypercholesterolemia, atherosclerosis, and high blood pressure. On the other hand, it supports cardiac mechanisms and improves vasodilation.
The fiber and fatty acids it contains also contribute to cardiovascular health and disease prevention.
This review from the Guelph Research and Development Centre (Canada) highlights the mechanisms of action of soy in preventing cardiovascular disease.
Is soy a health risk?
For many years, soy has been the subject of controversy because of its phytoestrogen content. These compounds are accused of causing hormonal imbalances in premenopausal women. In addition, because it reduces iodine absorption, it can cause thyroid dysfunction.
But these negative effects occur only in cases of excessive consumption. If you want to replace meat on your plates, eat it in reasonable amounts and vary your sources of plant proteins : cereals, legumes…
How to consume soy?
Soy-based preparations
There are many soy-based products. They are available as milk, flour, sprouts, soy sauce, soy protein or vegetable oil. It can also be consumed in the form of:
- tofu, une pâte blanche issue du caillage du lait de soja. Il peut être ferme (vendu sous forme de galettes ou de cubes) ou soyeux (à la texture plus souple et granuleuse)
- tempeh, une spécialité culinaire fabriquée à partir de graines de soja cuites, écrasées et fermentées
- miso, un aliment traditionnel de la cuisine japonaise obtenu à partir de pâte de soja fermentée.
Vegetarians and flexitarians will enjoy soy steaks, tofu vegetarian sausages, or nuggets made from soy protein. So many original and tasty alternatives to meat.
Soy flour
Little known, soy flour nevertheless offers flavor and nutritional benefits. Once harvested, the soybeans are ground into a powder to obtain a fine, light-yellow flour. Like rice flour, buckwheat or quinoa, soy flour is naturally gluten-free. It is therefore suitable for people who are intolerant, allergic, or sensitive to gluten.
Soy flour has a slightly bitter taste. If you don’t like it, opt for toasted soy flour with a hazelnut flavor, milder and sweeter. This flour is used to make breads, pasta, cakes, vegetarian patties… It can also be used to thicken and bind sauces, and to replace butter and eggs.
Soy lecithin
Soy lecithin is an emulsifying or stabilizing agent used as an additive in many processed foods. It is a byproduct of soybean oil, which contains choline, beneficial for the heart and liver, and which has good anti-cholesterol properties.
It is also available as a dietary supplement. In that case, be cautious about its origin because it may be derived from GMOs.
Consume sustainably: favor organic, local, and fair-trade soy
✓ Global soybean production is shared between the United States, Brazil and Argentina. France, for its part, has about 155,000 hectares of soy and its cultivation continues to grow. It is mainly grown in the southwest and east of France but also in Brittany, as here in Finistère.
✓ If you can, favor non-GMO soy, grown in France and organically farmed. Also choose fair-trade products to support the work of small farmers.
Dosage
It is recommended to consume about 30 g of soy per day.
Contraindications and side effects
Soy consumption has certain contraindications :
- Par mesure de précaution, il est déconseillé aux femmes enceintes et allaitantes et aux jeunes enfants ;
- Les personnes souffrant d’hyperthyroïdie doivent éviter d’en consommer ;
- En raison de sa teneur en isoflavones, sa consommation est déconseillée aux personnes ayant des antécédents personnels ou familiaux de cancers hormono-dépendants.
Excessive consumption can cause certain side effects :
- Troubles gastro-intestinaux
- Nausées
- Réaction allergique
If you experience side effects, stop consuming it and consult a doctor.
Report by Julia Perez
Sources and scientific studies
Gyoung-Ah Lee, Gary W. Crawford, Li Liu, Yuka Sasaki, Xuexiang Chen. 2011 Archaeological Soybean (Glycine max) in East Asia: Does Size Matter?
Aaron J Michelfelder, 2009. Soy: a complete source of protein.
Kyoko Taku, Keizo Umegaki, Yoko Sato, Yuko Taki, Kaori Endoh, Shaw Watanabe, 2007. Soy isoflavones lower serum total and LDL cholesterol in humans: a meta-analysis of 11 randomized controlled trials.
Kyoko Taku, Melissa K Melby, Nobuo Nishi, Toyonori Omori, Mindy S Kurzer, 2011. Soy isoflavones for osteoporosis: an evidence-based approach.
P Albertazzi, F Pansini, G Bonaccorsi, L Zanotti, E Forini, D De Aloysio, 1998. The effect of dietary soy supplementation on hot flushes.
