Transcript: Dietary Sources of Alkylphenol Endocrine Disruptors
There are many classes of endocrine-disrupting industrial pollutants. Concern about the alkylphenols first surfaced decades ago when a group at Tufts observed an excessive proliferation of human breast cancer cells in certain types of plastic containers, something you'd normally only see if the cells were exposed to some type of estrogen. They identified an alkylphenol as the culprit leaching from the plastic causing the estrogen-like properties when tested in the human breast tumor cells.
That's not good, so countries in Europe started banning and restricting uses of these chemicals, but the U.S. EPA has been slow to respond. A half million tons of these chemicals continue to be spewed out into the environment every year, so much so that now, they come down in the rain, and then accumulate up the food chain. I talked about the seasonal allergy epidemic in Japan; so where in the Japanese food supply can you find these potentially allergy-exacerbating endocrine disrupters? Predominantly chicken, and especially fish. Water animals and birds concentrate these compounds to levels several thousands of times greater than those in the environment, because these are fat-soluble chemicals. Therefore, they can easily contaminate foods of animal origin, which are thought to represent the most important source of human exposure to many organic pollutants, not just the alkylphenols. This group also found that fish was the worst.
Which type of fish? Anchovies and mackerel were the worst in this study, and salmon and cod in this study. In fact salmon was the only food found contaminated with nonylphenol diethoxylate, which is even more potent than regular nonylphenol.
And levels of contamination in fish were just the kind of concentrations that start to make breast cancer cells go crazy in vitro.
These findings are consistent with the fact that seafood consumption has been associated with severe asthma, current and severe rhinoconjunctivitis, which is like seasonal pollen allergies, and current and severe eczema, an allergic-type disease of the skin, in adolescent populations around the globe.
If these synthetic xenoestrogens are playing a role, what about natural phytoestrogens, like in soy foods? Turns out that in patients with asthma, consumption of a diet with moderate to high amounts of soy phytoestrogens is associated with better lung function and better asthma control, so if anything it's more these chemical pollutants, which come down in the rain, contaminate the soil, the plants, but then concentrate up the food chain in the fat of animals. And we're now like the ecosystem's peak predator, like the polar bear or bald eagle.
Thankfully there aren't many cannibals around anymore, though there is one group that continues to feed off human tissues. Alkylphenols have been found to concentrate in human breast milk, particularly in women who eat fish. The highest levels of these endocrine-disrupting pollutants were recorded in milk samples from mothers who said they ate fish at least twice a week, consistent with the fact that seafood consumption represents an important source of alkylphenol intake. And even these slightly elevated levels of endocrine disrupters in the milk of mothers with a seafood-rich diet may be associated with adverse effects on neurological development, fetal and postnatal growth, and memory functions in breastfed infants, because these contaminants may interfere with the endocrine, or hormonal, system.
Or even worse, straight animal fat, such as chicken fat, lard, and tallow, which were considered cooking oils here, or fish oil. Consumption of fish oil capsules and processed fish products was associated with alkylphenol concentration in mother's milk, again, thanks to bioaccumulation up the food chain. And then of course we recycle the leftover remains of farm animals into farm animal feed, and so the levels can get higher and higher in animal food products.
As one commentator responded, yes, these pollutants contaminate human milk, but they contaminate cow’s milk as well—we live in the same polluted world. In fact infant formula was found over 5 times more contaminated, so breast is still best—absolutely, but these kinds of studies are important in order to provide good suggestions for food choices to nursing mothers to prevent excess exposure to these pollutants in their infants.
We can kind of cut out the middlefish and move lower down the food chain in hopes of decreasing our exposure to industrial toxins.
To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by Ariel Levitsky.
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