Lead levels in breast milk invariably low : study
If breastfeeding mothers have been exposed to high amounts of lead, very little of this toxin is excreted in their breast milk.india Updated: Jan 13, 2006 12:16 IST
Findings from a new study should provide some reassurance to breastfeeding mothers that even if they've been exposed to high amounts of lead, very little of this toxin is excreted in their breast milk. In addition, the use of calcium pills may help bring down lead levels even further.
Dr. Adrienne S. Ettinger, of Harvard School of Public Health, Boston, and colleagues examined the contribution of cumulative lead exposure, breastfeeding practices, and calcium intake to levels of lead in breast milk among 367 women in Mexico City.
The investigators measured levels of lead in the blood and breast milk of the mothers at 1, 4, and 7 months postpartum, and obtained bone lead measurements at 1 month postpartum. Results of the study are published in the American Journal of Epidemiology.
The average levels of lead in breast milk at 1, 4 and 7 months were 1.4, 1.2, and 0.9 micrograms per liter, respectively a significant decreasing trend over the course of lactation.
"Even among this population of women who had relatively high cumulative lifetime exposures to lead, the concentrations of lead in breast milk were quite low," Ettinger pointed out to Reuters Health. "This provides additional reassurance that breastfeeding should be encouraged, because human milk is the best and most complete nutritional source for young infants."
Breastfeeding practice modified the relationship between lead levels in the bone and lead levels in breast milk. Women with high levels of lead in the knee bone who were exclusively breastfeeding had the highest levels of lead in the breast milk.
Calcium intake also had an effect on breast milk levels of lead. "Lactating women who were (randomly assigned) to receive 1200 mg of calcium had lower breast milk lead levels at seven months postpartum than women who were assigned to the placebo group," Ettinger said.
"Dietary calcium supplementation may constitute an important intervention strategy," she commented, "albeit with a modest effect, for reducing lead in breast milk and thus the potential for infant exposures, particularly among women with low dietary calcium intakes."
First Published: Jan 13, 2006 12:16 IST