Flashback Friday: Is Organic Meat Less Carcinogenic?

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.

This study, on “the carcinogenic risk associated with the intake of” various meats, estimated the risk was so great that we may not want to feed beef, pork, or chicken to kids more than like five times a month. This was in Europe, where lamb contamination is a particular problem. In the United States, if there was any standout, it would be chicken and PBDEs (flame-retardant chemicals)—not only compared to other meats, but other countries. U.S. chickens are like 10-20 times more contaminated than the samples taken from other countries that have been tested—though diet is not the only source of exposure, as those eating vegetarian have only about 25% lower levels in their bloodstream than those eating meat, though a large proportion of the levels in omnivores may be from chicken.

For other chemicals, diet may play a larger role. Studies of the “pollutants in [the] breast milk of vegetarians” dating back over 30 years have found the average vegetarian levels of some pollutants were “only 1 to 2 per cent as high as the [national] average.” In fact, for the six out of seven pollutants they looked at, there wasn’t even overlap in the range of scores; “the highest vegetarian value was lower than the lowest value obtained in the [general population].” This is presumed to be because these pollutants concentrate up the food chain. So, by eating lots from all the way down the food chain—plants—those eating vegetarian may “have an edge.”

For example, dioxins. “Meat, fish, and dairy are believed to contribute almost all of the dioxin body [exposure].” And, indeed, if you look at those eating strictly plant-based diets, they may only have about a third of the levels of dioxins and PCBs, or even less than a fifth, circulating throughout their bodies.

This study really struck me. “India has been facing a major problem of treating its [millions of pounds of electronic] waste” every year. And, these poor workers at these electronic waste recycling plants can be exposed to high levels of toxic chemicals, ending up with this kind of concentration of PCBs in their bloodstream—nearly twice as high as those living about 250 miles away along the coast. But these were non-vegetarian workers at the waste plant. The PCB levels of the vegetarians working at the same plant was even lower.

The problem with these cross-sectional studies is that we can’t single out the diet. Maybe vegetarians have other lifestyle behaviors that protect them. You don’t know until you put it to the test. Change people’s diets and see what happens.

That’s hard to do with persistent pollutants like PCBs, which may take literally decades to detoxify from the body. But, we can get rid of heavy metals, like mercury, in a matter of months. And, indeed, within three months of “the exclusion of meat, poultry, fish and eggs” from their diets, there was a significant drop in the levels of toxic heavy metals in their bodies, including mercury, cadmium, and lead.” Up to about a 30% drop within three months.

What if we just stick to organic meat? Certified organic meat comes from” livestock [that are] fed with organically produced feed that is free of pesticides and animal by-products,” by law. Therefore, one would assume “that there should be [a] lower accumulation of chemical residues.” However, on a practical level, there were simply “no studies on the chemical residues’ content in organic meat”—until, now.

Researchers “acquired 76 samples of [different kinds of] meat, both organic and conventional, and “quantified their levels of contamination with 33 different carcinogenic [persistent organic pollutants].”

After all, “the ingestion of food contributes more than 90% to the total current exposure to these compounds, especially…food [of] animal origin.” “On the other hand, an increasing number of consumers” are choosing organic. In fact, “organic food production increased by 50% during the last decade.” So, are consumers of organic meat protected, or not?

Well, “no sample was completely free of carcinogenic contaminants,” which is to be expected, given how polluted our world is these days. But, what was surprising was that “the differences between organically and conventionally produced meats were minimal.” Furthermore, “the current pattern of meat consumption exceeded the maximum limits” either way.

“Strikingly, the consumption of organically produced meat [not only] does not appear to diminish this carcinogenic risk,” but was sometimes found to “be even higher.” Bottom line, sadly, is that the “[c]onsumption of organic meat does not diminish the carcinogenic potential associated with the intake of [these pollutants].”

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• Huwe JK, Larsen GL. Polychlorinated dioxins, furans, and biphenyls, and polybrominated diphenyl ethers in a U.S. meat market basket and estimates of dietary intake. Environ Sci Technol. 2005;39(15):5606-5611.
• Eguchi A, Nomiyama K, Devanathan G, et al. Different profiles of anthropogenic and naturally produced organohalogen compounds in serum from residents living near a coastal area and e-waste recycling workers in India. Environ Int. 2012;47:8-16.
• Hernández ÁR, Boada LD, Mendoza Z, et al. Consumption of organic meat does not diminish the carcinogenic potential associated with the intake of persistent organic pollutants (POPs). Environ Sci Pollut Res Int. 2017;24(5):4261-4273.

Image credit: Ralph Aichinger via flickr. Image has been modified.

Motion graphics by Avocado Video.