Let’s Talk About Soy! EATING WELL

There are many different reasons for parents to choose meatless meals for the family, including cost, long-term health benefits, and humanitarian issues. Plant-based sources of protein such as soy have therefore become more popular in the United States. In 2021, nearly 14% of Americans chose a meat-free (vegetarian) diet, similar to China and Germany, while India still leads a vegetarian lifestyle with 41% of the country.

Soy-based products like tofu and tempeh are among the oldest forms of meat alternatives. Soybeans are a member of the legume family, along with beans, peas, lentils, and peanuts. Soy isoflavones are compounds found in soybean and soybean products. They have been reported to promote numerous physiological benefits, including the prevention and treatment of several diseases such as coronary heart disease, diabetes, and osteoporosis, and even have positive effects on learning and memory. But you may have heard controversy around soy as well – mainly because soy isoflavones are phytoestrogens, similar in function to human estrogen but much weaker. Let's take a look at some of the facts about soy so you can make an informed decision.

According to the National Institute of Health (NIH)

• Consuming soy protein in place of other animal proteins may lower levels of total cholesterol and LDL, the “bad cholesterol.”

• Soy protein may slightly reduce blood pressure in people with hypertension (high blood pressure).

• Observational studies show that among Asian women, a higher intake of soy during childhood and adolescence is associated with a lower risk of breast cancer later in life. The amount of soy in Western diets may be too low for this association to be observed.

• Current evidence indicates that it’s safe for women who have had breast cancer or who are at risk for breast cancer to eat soy foods; however, soy in a supplement form has not been shown to reduce the risk of breast cancer, and it’s unknown if it’s safe.

• Except for individuals with soy allergies, soy is considered to be safe.

• Some individuals may still experience common side effects such as constipation or diarrhea from consuming soy.

• Avoid taking soy isoflavones if you have kidney stones, as they may increase a chemical (oxalate) that contributes to kidney stones.

• The use of soy in amounts greater than those commonly found in foods may be unsafe during pregnancy, and little is known about whether it’s safe to use soy in amounts greater than the amount commonly found in foods during breastfeeding. Isoflavones are transferred to the fetus through the placenta and are excreted in human milk.

A soy allergy is more common in infants and young children than in older children and adults. Approximately 0.4% of infants in the U.S. have a soy allergy. Most children will outgrow their soy allergy (many by the time they are 3 years of age), although some individuals will remain allergic to soy throughout their lives. Many children outgrow the allergy by the age of 10. Allergic reactions to soy are typically mild, but any food reaction can be unpredictable. Rare, severe, and potentially life-threatening reactions (anaphylaxis) can also occur. Individuals with a soy allergy may be more likely allergic to other major allergens such as peanuts, tree nuts, eggs, milk, and sesame.

What about soy infant formula? Soy infant formula (also marketed as plant-based formula) is an alternative to cow’s milk-based formula. The American Academy of Pediatrics (AAP) supports breastfeeding as the preferred feeding of choice but states that soy formulas can be used “in situations in which a vegetarian diet is preferred” or indicated “for infants with hereditary disorders that make them unable to properly digest milk (such as galactosemia) or the rare condition of hereditary lactase deficiency.” Soy infant formulas are not recommended for premature infants.

The bottom line is, incorporating soy into your family’s diet as a meat substitute is safe and can add health benefits. Talk to your doctor before taking a soy isoflavone supplement because it would likely be a greater amount than what you would normally consume in foods, and the long-term effects of taking soy isoflavone supplements are still an ongoing investigation. j

Aurea Thompson MSH, RDN, CSP, LDN Certified Pediatric Nutrition Specialist Wolfson Children’s Hospital