Breast-Feeding May Calm New Mothers Stress

New York NY, March 23, 1998--Most of us know that breast-feeding is good for the baby, but what about for the mother? Researchers at Columbia University College of Physicians & Surgeons have found mothers who breast-feed are less likely to feel stressed during the post-partum period than mothers who do not. The results suggest that breast-feeding may activate a "stress-buffering" mechanism. The study, reported at the American Psychosomatic Society's 56th annual meeting, was designed to see if breast-feeding affects a new mother's experience of daily stress or changes her psychological and physiological reactions to induced stressors. Earlier studies suggested that breast-feeding may lower the level of stress that a new mother feels.

Researchers discovered that mothers who breast-fed reported feeling the lowest levels of stress than mothers who did not breast-feed. However, mothers who breast-fed only part of the time demonstrated the highest degree of physiological response to an induced stressor stimulus. This was true even when researchers controlled for other factors such as whether a mother worked, or exercised, the number of other children she had, or the number of months she was post-partum, according to Elizabeth Sibolboro Mezzacappa, Ph.D., a research fellow at Columbia-Presbyterian Medical Center and lead author of the study.

"It seems that exclusive breast-feeding calms the mother and this effect doesn't appear to be based on differences in personality or circumstance but on the actual physiological effects of breast-feeding," says Dr. Mezzacappa.

The study followed four groups of new mothers who gave birth within the last year: mothers who had never breast-fed their babies, mothers who had started but subsequently stopped breast-feeding, mothers who breast-fed and bottle-fed, and mothers who exclusively breast-fed. Each mother completed standardized questionnaires designed to assess their personality for baseline anxiety traits and to measure the stress experienced in the past month. Results showed that while mothers did not differ in their levels of baseline anxiety, the breast-feeding mothers reported feeling the least stress. The researchers also measured physiological stress by asking the mothers to perform mental arithmetic and cold pressor tests (placing a hand in ice water)--tasks routinely used by researchers as simulators of stress. To quantify physiological responses, the mothers' skin electrical activity was recorded before and during each task. This "electrodermal response" is thought to be an index of the body's emergency or stress activated system. Mothers who were both breast- and bottle-feeding showed the greatest response to the cold pressor test. No significant differences were seen in response to the mental arithmetic task.

The results support the notion that breast-feeding makes women feel calmer or less stressed. However, when a mother breast-feeds only part of the time, such as during weaning, stress-exacerbating mechanisms may be involved which make her more vulnerable to the physiological effects of stress. Says Dr. Mezzacappa, "The results are complex, but they do demonstrate that breast-feeding and weaning have an impact on a mother's well-being. Clearly, further studies are needed in this critical area."


American Psychosomatic Society, Elizabeth Sibolboro Mezzacappa, Physicians Surgeons, Says Dr