02 October 2008

The Pros and Cons of Breastfeeding

As if being a mother isn't tough enough, here's more to think about from the latest issue of Environmental Health Perspectives. But first, an interesting factoid to share at happy hour:

Breastfeeding infants are technically the highest members of the food chain. Strictly speaking I suppose this would apply not just to infants but to anyone feeding off breast milk. In any case, humans are at the top of the food chain because we eat everything else. But since the food source for breastfeeding infants is a human at the top of the food chain, the infants are considered to be above adult humans. Strange but true.

And now the crux:

The health benefits to the infant of breastfeeding have been amply documented; numerous studies strongly indicate significantly decreased risks of infection, allergy, asthma, arthritis, diabetes, obesity, cardiovascular disease, and various cancers in both childhood and adulthood.

Nevertheless, given the tendency for persistent organic pollutants (POPs), pesticides, heavy metals, and other contaminants to accumulate in human milk, researchers and parents alike are asking whether the nursling's exposure to these pollutants might reduce or even override the health benefits.

The POPs, which include polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), and certain organochlorine pesticides such as DDT, all tend to become magnified in the food chain over time. Breastfeeding infants are thus the final target of POPs.

In recent years, additional chemicals have been detected in human milk, among them bisphenol A, polybrominated diphenyl ethers (PBDEs), hexachlorobenzene, and the cyclodiene pesticides, which include dieldrin, heptachlor, and chlordane. Residues of many banned POPs persist in women's milk.

Yet, the literature to date supports the idea that the benefits of breastfeeding generally outweigh the hazards posed by infant exposure to POPs in human milk.

...documented adverse effects on breastfeeding infants—such as impairment of psychomotor development and other neurodevelopmental outcomes—have been seen primarily in cases of high-dose poisonings in which the mother became clinically ill.

...up to 90% of human exposure to the persistent and lipid-soluble dioxin-like chemicals, including certain PCBs, PCDDs, and PCDFs, is attributed to dietary intake... Meat eaters in general tend to harbor more POPs than people eating predominantly vegetarian diets.

Nursing mothers can also reduce the level of POPs in their milk by maintaining their weight to avoid mobilizing fat stores, says Jenny Pronczuk, a WHO medical officer ... who adds that reducing emissions of POPs into the environment is the long-term solution to this problem...

Because of human milk's nutritional, immunologic, anticancer, and detoxifying effects, Wang, Rogan, and other environmental scientists encourage women to continue the practice of breastfeeding even in the context of widespread pollution. "At the same time," says Pronczuk, "breastfeeding mothers should be helped and advised on how to avoid alcohol and drugs and remove themselves from polluted environments, while also creating healthier, safer, and cleaner environments for themselves and their children."

1 comment:

LDP said...

Meanwhile, PETA asks Ben and Jerry's to switch from cow's milk to human breast milk in its ice cream.