In salads, creams and desserts but also in the form of steak or drink, soy products are now very present in our diet, especially among vegetarians. The problem: these foods could disrupt the hormonal system. If they are not prohibited in pregnant women, precautionary measures should be taken.

Soy, like many foods, contains phytoestrogens, hormones that belong to the isoflavone family. Once ingested, they are partly made active by the action of the intestinal flora and act like natural or synthetic hormones, but with an efficiency 1000 to 2000 times less.

We now know that phytoestrogens have strong structural similarities with estradiol, one of the two main female hormones. They will attach themselves to the estrogen receptors and will either fill the deficits or compensate for the hormonal excesses. By mimicking the effects of female hormones, they could therefore a priori disrupt the hormonal system.

Animal experiments show that phytoestrogens can have unwanted effects on the young. This has not been observed so far in humans, but the National Institute for Prevention of Health Education (Inpes) still recommends as a precaution to limit soy consumption during pregnancy as long as other studies have not demonstrated its perfect safety.

Animal experiments show that isoflavones can have adverse effects on young. However, this has not yet been verified in humans, but as a precautionary principle, during pregnancy, it is recommended to limit the consumption of soy foods.

Afssa sets out a benchmark that is easy to remember for future mothers: no more than one food containing soya per day throughout the duration of pregnancy but also during the breastfeeding period.

All soy foods contain phytoestrogens are therefore concerned by this precautionary measure:

• soybean sprouts
• tofu
• vegetable soy drink, also called tonyu or soy juice
• soy yogurts
• Tempeh
• seitan
• soy steak
• soy biscuit
• and any other product containing soy

Inpes also advises to avoid food supplements containing soy extracts during pregnancy. To do this, read the list of components carefully and never take food supplements without the consent of your doctor or pharmacist.In general, do not self-medicate during pregnancy.

Soy products are a source of vegetable protein and essential fatty acids of interesting quality for future vegetarian mothers. Thus, if you are vegetarian, it is better to tell your doctor who can advise you on the diet that is best for you and your child.

However, for vegetarian pregnant women, equivalences are possible to replace meat, without consuming soy products. Eggs are indeed excellent sources of protein: in addition to containing all the essential amino acids, their assimilation is excellent. Mixtures of cereals and legumes are also an excellent alternative to meat to provide all the essential amino acids.

In terms of quantities, we can count that a portion of protein =

• 2 eggs
• 150 to 200 g of fish
• 100 g of cooked cereal starches (pasta, rice, semolina, bulgur, wheat, etc.) combined with 50 g of cooked pulses (lentils, chickpeas, split peas, white or red beans, etc.)

The recommendations are very clear: Afssa advises against soy-based foods before 3 years.

For its part, ANSES confirmed, by analyzing the compositions of 211 vegetable juices, including soy-based drinks and milk from animals other than cows, that most of the nutritional needs of infants were absolutely not covered by these drinks:

• the energy intake is below the threshold set by the regulations on infant nutrition in 73% of cases,
• the protein intake is insufficient or too high in 83% of cases,
• lipid intake is not high enough in 77% of cases,
• sodium intake is inadequate in 69% of cases.

This official opinion from ANSES has once again sounded an alarm bell sounded for several years now by the pediatricians who receive these deficient children (calcium, sodium, potassium, proteins) in the emergency services in the hospital. These vegetable drinks can have serious repercussions on the growth of babies and trigger severe pathologies. And this, especially since the use of these juices is early and prolonged.

The opinion of pediatricians is also unanimous: vegetable milks are strongly discouraged and only infant formulas based on soy proteins (PPS) are suitable for children under 3 years old. Vegetable soy drinks, such as those sold in supermarkets in the organic section are therefore strongly discouraged for babies.