Joe Schwarcz: PETA’s science is for wing nuts
Gentlemen, don’t look now, but if you are coming up short in your shorts, it may be because your mother ate too many chicken wings while she was pregnant. At least that was the message delivered to the organizers of the National Buffalo Wing Festival by People for the Ethical Treatment of Animals, the extremist animal-rights activist group. PETA claims that “findings published by the Study for Future Families showed that eating poultry during pregnancy may lead to smaller penis size in male infants.” Actually the study showed no such thing. There is no mention of poultry at all. PETA is guilty of spreading junk science.
And just what is junk science? Unfortunately that term is often bandied about by people who use it in a derogatory fashion to dismiss any research with which they don’t happen to agree. But let me offer a scientific definition of junk science: I see it as any argument that claims to have greater support than the evidence actually justifies, usually to advance a political or commercial agenda or to buttress a personal conviction.
Now let me explain why PETA’s linking of poultry consumption with male shortcomings is for the birds.
The study referred to by PETA investigated the effects of prenatal exposure to chemicals called phthalates on the development of the male reproductive tract. Why should this be of any interest to researchers? Two reasons. First, we all have detectable levels of phthalates in our blood and urine, which is no great surprise since these chemicals find wide application in food packaging, medical devices, automobile interiors, adhesives, gloves, textiles, toys, flooring, wall coverings, paints and personal-care products. Second, some phthalates exhibit hormone-like properties, which is always a concern given that minute changes in hormonal activity can have major health effects.
Phthalates aroused the curiosity of scientists when a study by Professor Shanna Swan of the University of Rochester discovered an association between the ano-genital distance in male rats and their mothers’ exposure to phthalates. The mental image of a scientist using calipers to measure the distance between the anus and the genitals of a rat may well elicit chuckles, but this distance is indeed a function of circulating male hormones. The “Study for Future Families” was sparked by the rat experiments and was designed to explore the possibility that, at least when it comes to phthalates, humans are basically giant rats.
Researchers analyzed urine samples collected from the mothers of 85 boys during pregnancy for nine different phthalate metabolites to give an indication of exposure. Then between the ages of 2 and 36 months, pediatricians measured the boys’ ano-genital distance, the size of their testes and the width and length of their penis. An inverse association was found between the urinary concentration of five metabolites and ano-genital distance. As far as penis size goes, there was an association between width and the metabolites of DEHP (diethylhexylphthalate), one of the most common phthalates, but no association at all with length.
And how do chicken wings enter into this picture? Via a spurious scheme hatched by PETA’s publicity machinery.
Chickens, like virtually everything else we eat, do contain some phthalates. These may originate from packaging, butchers’ plastic gloves, water pipes in henhouses or a myriad other sources. So, here is PETA’s specious argument: Phthalates are associated with a smaller penis, chickens contain phthalates, therefore eating chicken wings during pregnancy leads to a smaller penis.
What’s wrong with this picture?
For one, there is no study that has examined chicken-wing consumption and penis size! Suggesting that indulging in chicken wings leads to smaller penises is not backed by evidence — and is simply junk science.
PETA’s venture into junk science of course does not mean that there are no real issues with phthalates. While not conclusive, studies have linked phthalates with respiratory issues, allergies, insulin resistance, sperm damage, decrease in sperm count, reduced levels of testosterone and thyroid hormones and increased waist circumference. This is why researchers are following the health status of people in Taiwan with keen interest.
In 2011 the country was rocked by the revelation that some unscrupulous food producers had replaced palm oil with DEHP in the formulation of “clouding agents” used to impart a cloudiness to fruit drinks in order to make them resemble natural fruit juice as closely as possible. Such artificially coloured and flavoured beverages are of questionable nutritional value in the first place, but adulterate them with phthalates and you have a real issue. Especially when such tainted products are used to make jams, jellies, Popsicles, flavoured teas, yogurt and dietary supplements. And why the adulteration? Money. Phthalates are cheap and allow for longer shelf life.
As one tainted food showed up after another, fear and panic spread, especially among pregnant women who had heard about the possible connection between the “plasticizer” contaminant and possible sex-organ malformation in their offspring. Taiwan’s international image also suffered a blow as many of the adulterated foods were exported to other countries, including Canada and the U.S. And then, of course, there was the huge financial burden of a food recall. As expected, a thorough investigation was launched, generating a great deal of anger with the finding that the adulteration had probably been going on for decades. Figuratively, it was a sickening situation. Whether it turns out to be literally sickening as well remains to be seen. So far, no adverse effects have been linked to the scandal. But when it comes to hormone-like chemicals, the effects may be subtle and not immediately apparent.
The extensive food adulteration in Taiwan was a real issue, not like PETA’s silly clucking about pregnant women being advised to abstain from “chomping on chicken wings or their sons could come up short.” The only thing that comes up short is PETA’s junk science-based argument.