Transcript: Meat Fumes: Dietary Secondhand Smoke
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 last time I talked about this study was in the context of the carcinogens in the smell of frying bacon—the ability of the fumes generated by frying meat to mutate DNA, potentially explaining both the “increased risk of respiratory tract [cancer] among cooks” as well as the “lower proportion of deaths from respiratory diseases and lung cancer among vegetarians.”
This was borne out in a new study on the exposure of pregnant women to both the consumption of grilled meat, as well as just exposure to the airborne fumes of grilling meat—even if they didn’t eat it. Yes, the study found evidence that prenatal exposure to polycyclic aromatic hydrocarbons from a “diet including grilled meat might be hazardous for fetal development.” For example, the “effect of ingested barbecued meat consumed in the last pregnancy trimester resulted in [a] birth weight deficit of 165 g,” a significantly smaller birth weight.
But, even if she didn’t eat it, airborne exposure alone amounted to a birth weight deficit. Compared to no exposure, oral or airborne, just being around the barbecue was associated with a birth weight deficit, including a smaller head circumference in the newborn—nearly the same head shrinkage seen if she actually ate the meat. See, “[a]fter being absorbed into the body, [these cooked meat] compounds are distributed to almost all internal organs and are transferred through the placenta to the fetus,” and it appears “that newborns and young children are especially vulnerable to the toxic effects…in terms of birth outcomes. Most importantly, it was recently documented that prenatal exposure to airborne PAH may also have an effect on the future cognitive development of children.” We should never smoke around children; maybe, we should stop grilling around them, as well.
Even just living next door to a restaurant preparing meat may pose a hazard. They measured the “incremental lifetime cancer risk,” the excess cancer cases expected in back-door neighbors of restaurants, given what’s spewing out of the exhaust outlets attached to the fume hoods in the kitchen.
They compared what was coming out of Chinese restaurants, American-style restaurants, and barbecue joints. Which do you think was worse? It was the Chinese! Why not the barbecue places? Well, they think it was because of the fish. They’re broiling more fish in Chinese restaurants than in the barbecue joints.
How bad is it? Well, they estimate that given the excess cancer risk, you wouldn’t want to live behind a Chinese restaurant more than a day or two a month—though maybe you could squeeze in an extra day behind one of the other restaurants.
Their model suggests it may be riskier for adults, since they breathe more, eat more, and have more skin for the carcinogens to be absorbed through, compared to children. Instead of trying to breathe less, though, it might be better to just move—or, convince the restaurant to go vegetarian.
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