We have all heard that breast milk is the best source of nutrition for a newborn. But exclusive breastfeeding for a long time may expose infants to a class of industrial chemicals linked with cancer and immune system dysfuntion, finds a new research.
The chemicals --perfluorinated alkylate substances, or PFASs - appear to build up in infants by 20-30% for each month they are breastfed, the findings show.
"There is no reason to discourage breastfeeding, but we are concerned that these pollutants are transferred to the next generation at a very vulnerable age," says one of the researchers Philippe Grandjean, adjunct professor of environmental health at Harvard TH Chan School of Public Health in Boston, US.
"We knew that small amounts of PFAS can occur in breast milk, but our serial blood analyses now show a buildup in the infants, the longer they are breastfed," Grandjean points out.
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PFASs are used to make products resistant to water, grease, and stains. These compounds --which tend to bioaccumulate in food chains - are found regularly in the blood of animals and humans worldwide, and have been linked with reproductive toxicity, endocrine disruption, and immune system dysfunction.
For the study, the researchers follow 81 children who were born in the Faroe Islands between 1997-2000, looking at levels of five types of PFASs in their blood at birth and ages 11 months, 18 months, and five years.
In children who are exclusively breastfed, PFAS concentrations in the blood increase by roughly 20-30% each month, with lower increases among children who are partially breastfed.
After breastfeeding is stopped, concentrations of all of five types of PFASs decrease.
The study appeared online in the journal Environmental Science and Technology.