Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Health & Baby

Font Size

Soy and Cow's Milk-Based Baby Formulas Face Off

Soy and Cow's Milk-Based Formulas Offer Similar Developmental Benefits, but Breast Milk Is Best
WebMD Health News
Reviewed by Louise Chang, MD

May 29, 2012 -- Soy and cow's milk-based baby formulas may offer similar developmental benefits for baby. But a new study confirms breast milk still is the best.

Researchers found no differences in behavioral development, such as language and other thinking-related skills, between infants fed soy formula or milk formula during the first year of life.

Breastfed babies, however, had a slight advantage.

"Although all three diet groups scored within the established norms in the behavioral testing, BF [breastfed] infants scored slightly better than formula-fed infants," researcher Aline Andres, PhD, of Arkansas Children's Nutrition Center in Little Rock, Ark., and colleagues write in Pediatrics.

The American Academy of Pediatrics recommends breast milk first as the ideal source of nutrition for infants, followed by milk and soy formulas as the second and third choices, respectively.

Researchers say about two-thirds of U.S. infants were breastfed as newborns in 2008, but nearly three-fourths of them were transitioned to baby formula by age 6 months. Overall, about 20% of infants in the U.S. are fed soy protein-based formulas during the first year of life.

Several studies have shown that the growth and physical development of infants fed soy formula is similar to that of infants fed milk-based formulas.

But researchers say concerns have been raised about the isoflavone content of soy protein-based formulas. Isoflavones are estrogen-like compounds found in plants, which some have suggested may have effects on the brain and nervous system development.

Small Differences, Breast Milk Best

In this study, researchers compared the development of 391 healthy infants fed breast milk, milk-based baby formula, or soy-based baby formula. The infants were followed for one year from birth and tested every three months.

The results showed no differences between soy formula and milk formula-fed infants on all developmental tests.

Breastfed infants, however, had an advantage over formula-fed infants in three different developmental areas:

  • Mental development: Breastfed infants scored slightly higher on the Mental Development Index at 6 and 12 months compared with formula-fed infants.
  • Psychomotor skills: Infants fed breast milk also had higher scores on motion skills tests at 6 months than infants fed soy formula.
  • Language skills: Breastfed infants had slightly higher scores on the Preschool Language Scale-3 than milk-based formula-fed infants at 3 and 6 months.

Researchers say it is important to point out that differences between breastfed and formula-fed infants were quite small after adjusting for other factors like being small for gestational age, etc.

They say the infants involved in this study will also be followed until age 6 years to see if there are any long-term developmental differences.

Baby's First Year Newsletter

Because every week matters, get expert advice and facts on what to expect in your baby's first year.

Today on WebMD

mother on phone holding baby
When you should call 911.
parents and baby
Unexpected ways your life will change.
baby acne
What’s normal – and what’s not.
baby asleep on moms shoulder
Help your baby get the sleep he needs.

mother holding baby at night
mother with sick child
Chinese mother breast feeding newborn baby girl
Track Your Babys Vaccines
Baby Napping 10 Dos And Donts
Woman holding feet up to camera
Father kissing newborn baby
baby gear slideshow