5 Scary Side Effects Of Soy Milk In Toddlers

Breastmilk is the best source of nutrition to your newborn. After the baby is around 6 months old, along with breastmilk or formula milk, cow’s milk is usually suggested for weaning. However, some babies have lactose intolerance, which makes it difficult for them to digest cow’s milk. In such cases, soy milk is considered as an effective alternative. Though beneficial, it comes with its own side effects, which you need to be aware of.

Mentioned below are the reasons why you should think twice before feeding soy milk to your little one.


Side Effects Of Soy Milk In Toddlers

1. Causes Allergic Reactions

Soy milk leads to allergic reactions

Although soy milk is considered as a fill-in for cow’s milk, there is no evidence which shows soy milk does not induce dairy allergy. The reason, in this case, is not lactose but the proteins present in soy.


The allergic reactions range from mild to severe. While skin rashes, gastrointestinal distress, and nausea are mild symptoms, severe symptoms like anaphylaxis can occur, when not treated immediately. This is a condition which leads to swelling of the throat and difficulty in breathing, ultimately leading to death.

2. Slows Brain Development

Soy milk hinders brain development


Apt nutrition during the first year of your baby’s birth is crucial. It is the time when all the organs are developing rapidly and the baby is getting acquainted with the extrauterine world. By the end of the first year, it should ideally weigh slightly more than double of its birth weight.

Cow’s milk has proteins which aid this growth and development process. Soy milk, though has proteins like trypsin inhibitors, does not contribute to growth. Trypsin inhibitors are large proteins which hinder the digestion and absorption of nutrients. Though infant soy formula brands ensure the absence of trypsin inhibitors, some, unfortunately, remain even after processing. These have the potential to slow down the baby’s brain development, leading to a weak nervous system and retarded growth.


3. Disrupts Thyroid Functioning

Soy milk disrupts thyroid gland functioning

Considered as one of the severe side effects of soy milk, disruption of thyroid functioning is attributed to the presence of phytoestrogens/isoflavones (plant-based estrogen). It is estimated that infants fed with soy milk exclusively, receive estrogen equivalent to 5 birth control pills every day. Scary, isn’t it?


Various studies were conducted on both boy and girl babies and the results were devastating. Boy babies when fed with the estrogen-like female hormone, showed severe developmental issues at puberty. Since the baby’s testosterone levels in the first few months of birth are as high as an adult male, hampering the levels with female hormones posed severe issues. The issues were primarily related to maturation and patterns of male behavior.

In case of girls, an early maturation by the age of 12.5 was observed. This further led to problems in later life related to infertility and breast cancer.


Apart from these, both genders showed problems like mental confusion, fatigue, slowness, hair loss, constipation, and heart disease.

4. Leads To Protein Deficiency

Soy milk gives rise to protein deficiency


Cow’s milk is rightly defined as the “complete food,” owing to its nutritional value. It has just the right amount of protein to support baby’s growth and development. Soy milk, on the other hand, has 25% less protein than cow’s milk. This results in protein deficiency in the baby.

Lack of proteins leads to a cascade of problems like weakness, slow heart rate and pulse, decreased blood pressure, and decreased heart size. Your little one could also become weak, lose muscles, and in severe cases, experience multiple organ failures.

5. Blocks Absorption Of Minerals

Soy milk prevents mineral absorption

An acid called phytic acid is present in large amounts on the outer surface of soybeans. This acid blocks the absorption of vital minerals like zinc, calcium, iron, and magnesium in the body.

A study conducted on toddlers who consumed soy milk formula showed a severe deficiency in calcium and zinc particularly. Calcium deficiency led to weaker bones and teeth apart from joint and muscle pain. It also affected the working of hormones in the body. Zinc deficiency affected the optimal functioning of the brain and nervous system. Some cases of decreased IQ were also reported.

All these reasons make soy milk a definite no-no as cow’s milk substitute. In case your baby is lactose intolerant, choosing goat milk is a good option. The fat and protein compositions are easily digestible by the babies. In any case, it is good to consult with your baby’s pediatrician before beginning a new diet.