Breast-Feeding Best Choice for Infant, Mom

Q:  I have heard that breast milk is better for an infant's health than formula and also that breast-feeding is good for the mother. Is this true?

A:  Yes. Breast milk helps prevent infection and breast-fed infants have lower hospitalization rates. Breast milk contains a mother's antibodies, which are particles circulating in the blood that ward off infection. Every person carries different antibodies depending on what infections we have been exposed to. For example, when you have a cold virus, your body makes an antibody to that specific virus and the antibody helps to neutralize the infection. If a breast-feeding mother has a cold, she develops the antibody, and then when the infant gets the same cold, the infant will be less affected because he or she already received the antibody in the breast milk. Similarly, because I've had the flu vaccine, my infant son has some protection against the flu.

Breast milk is by definition nutritionally complete; formula only mimics breast milk. And breast milk is dynamic. Immediately after birth, the breast milk helps stimulate the newborn's bowels. Breast milk composition changes both as the infant grows and from the first drops (more water content) to the last drops (more fat content) of a feeding.

Breast milk also has different flavors depending on the mother's diet, so breast-fed babies experience a variety of tastes. Finally, a recent study found children who were breast-fed as infants were smarter than formula-fed children, but the difference in IQ scores was only one point, hardly meaningful.

I would be remiss not to mention the health benefits for the mother. Many mothers enjoy the unique bond that breast-feeding can provide. After delivery, breast-feeding helps the uterus to contract to normal size. Also, breast-feeding may help the mother return more quickly to her pre-pregnancy weight and may reduce the risk of breast cancer.

Ann Nattinger, MD, MPH, a Professor of Medicine at the Medical College of Wisconsin, tells me that although the clinical research is not definite, the more recent and higher quality studies show a small reduction in breast cancer among women who have breast-fed, and the more often and the longer duration, the better. This benefit may be limited only to breast cancer that occurs before menopause.

Dr. Nattinger explains that, while estrogen seems to increase the risk of breast cancer, breast-feeding reduces estrogen levels. However, to put the effects of breast-feeding and breast cancer in perspective, Nattinger mentions that there is a more clear-cut association of alcohol ingestion and breast cancer, so if your main goal is to reduce breast cancer risk, the best thing you can do is decrease alcohol intake.

Julie L. Mitchell, MD, MS, is an Assistant Professor of Medicine at the Medical College of Wisconsin. She practices internal medicine at the Froedtert & Medical College General Internal Medicine Clinic - East. Her column appears in the Milwaukee Journal-Sentinel.