June 22, 2021
Infants given soy formula over breastmilk were exposed to the equivalent of 5 birth control pills and had between 13,000-22,000 times more serum estrogen.
Soy formula contains phytoestrogens, genistein and daidzein (also called isoflavones).
No phytoestrogens have been detected in milk-based formulas.
Around 25% of American fed formula are given soy formulas, according to NACD.
The Problem With Soy Formulas
A study found that infants on soy formula only have levels of serum estrogens between 13,000-22,000 times greater than infants who were either breast fed or given dairy-based formulas instead [R].
A report from the Swiss Bulletin de L’Office Federal de la Santé Publique found that 100 mg isoflavones in soy protein taken by adult women weighing roughly 60kg would provide the estrogenic equivalent of a birth control pill.
If you were to adjust for weight, bioavailability, and quantity, then the daily average consumption for a baby weighing 6kg would be the estrogenic equivalent of roughly 4-5 birth control pills a day!
Male infants experience a testosterone surge in the first few months of life. It is believed that during this period, the infant will begin to express male characteristics after puberty such as in the development of sexual organs and in physical traits like muscular development or deepening of the voice.
A deficiency of these hormones may cause problems with spatial perception and learning difficulties. Additionally, studies have shown that humans need animal fat for optimal neurological health, in spite of pushes to advance plant-based diets. A vegan diet in children has been shown to leave them with stunted height and weaker bones over their meat-eating peers.
The introduction of strong phytoestrogens may disrupt natural hormonal balances and potentially spell long-lasting ramifications.
Soy isoflavones in soy products can depress thyroid function, causing autoimmune thyroid disease, metabolic disruption, and even cancer [R].
Soy, a well-known anti-nutrient, inhibits the thyroid’s uptake of iodine — important for thyroid function — and spikes thyroid stimulating hormone (TSH) levels to compensate.
Infants consuming soy formula as their only food are exposed to 10 times the levels of isoflavones per kilograms of body weight than the amount shown to cause thyroid suppression in adults after three months of exposure.
Babies were also reportedly more efficient at processing dietary estrogens than adults [R].
Infants may also suffer from intestinal problems and allergies from consuming soy formulas.
Soy, Soy Formulas, and Beyond
In the past, we’ve covered the negative health effects of soy in men and animals alike.
Japanese researchers managed to convert a male catfish into a biological female using soy isoflavones. Monkeys became aggressive loners after exposure to a soy-based diet. Rodents suffered neurological damage in their ability to bond after long term consumption of soybean oil.
And beyond the animal kingdom, the demand for soy has led to millions of acres of deforestation.
If you have concerns about consuming soy or soy products, we recommend a diet comprised of whole foods. Avoid any processed or pre-packaged food.