Transcript: Flame-Retardant Pollutants and Child Development
Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.
The results of the CHAMACOS study were published recently–the Center for the Health Assessment of Mothers and Children of Salinas Valley California–investigating the relationship between exposure to flame-retardant chemical pollutants in pregnancy and childhood, and subsequent neurobehavioral development. Why California? Because California children’s exposures to these chemicals are among the highest in the world, considered to be endocrine disruptors and neurotoxins. What did they find? Both prenatal and childhood exposures to these chemicals were associated with poorer attention, fine motor coordination, and cognition (particularly verbal comprehension) by the time the children reached school age. This study, the largest to date, contributes to growing evidence suggesting that these PBDEs–polybrominated diphenyl ethers–(flame-retardant chemicals) have adverse impacts on child neurobehavioral development. And, the adverse effects may extend into adolescence, again affecting motor function as well as thyroid gland function, something that may extend into adulthood.
These chemicals get into the moms, then get into the amniotic fluid, and then into the breast milk. And the more that’s in the milk, the worse may be the infants’ mental development. Breast is still best; but, how did these women get exposed in the first place?
The question: is exposure mostly from diet, or dust? Researchers in Boston collected breast milk samples from 46 first-time moms, vacuumed up samples of dust from their homes, and questioned them about their diets. They found that both were likely to blame. Diet-wise, a number of animal products were implicated. That’s consistent with what’s been found worldwide. For example, in Europe, these flame-retardant chemical pollutants are found mostly in fish, meat, and other animal products. It’s similar to what you see with dioxins: fish and other fatty foods, with a plant-based diet offering the lowest exposure.
Well, if that’s the case, do vegetarians have lower levels of flame-retardant chemical pollutants circulating in their bloodstreams? Yes, vegetarians had about 25% lower levels. Poultry appeared to be the worst. USDA researchers compared the levels in different meats, and the highest levels were found in chicken and turkey, with less in pork, and even less in beef. California poultry had the highest, consistent with strict furniture flammability codes, but it’s not like chickens are pecking at the furniture. Chickens and turkeys may be indirectly exposed through the application of sewer sludge to fields where feed crops are raised, contamination of water supplies, the use of flame-retardant materials in poultry housing, or the inadvertent incorporation of fire-retardant material into the birds’ bedding or feed ingredients.
Now fish have been shown to have the highest levels overall, but Americans don’t eat a lot of fish, and so they don’t contribute as much to the total body burden in the United States. Here’s the level they found in meat-eaters. Here’s the amount found in the bloodstream of vegetarians. Just to give you a sense of the contribution of chicken, here’s where higher-than-average-poultry eaters ended up, compared to lower than average.
Where did the vegans end up? Well, we know the intake of many other classes of pollutants is almost exclusively from the ingestion of animal fats in the diet, so, what if you take them all out of the diet? Well, it works for dioxins. Vegan dioxin levels appear markedly lower than the general population, but what about for the flame retardant chemicals? Vegans came out down here, with long-term vegans–a few who’ve been vegan around 20 years–even lower. This tendency for chemical levels to decline the longer one eats plant-based suggests that food of animal origin contributes substantially, but note the levels never get down to zero; so, diet is not the only source.
The USDA researchers note that there are currently no regulatory limits on the amount of flame-retardant chemical contamination in U.S. foods, but reducing the levels of unnecessary, persistent, toxic compounds in our diet is certainly desirable.
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