Below is an excellent article by Professor Joe Schwarcz of McGill University’s Office for Science and Society addressing the paranoia about “chemicals” in our food and environment.
I don’t think Einstein had chemical anxiety or the number of chemicals in our urine in mind when he famously stated that “not everything that counts can be measured and not everything that can be measured counts.” But I think the quote has great relevance given that scarcely a day goes by without some concerned group clamoring about our exposure to “untested” chemicals and lamenting the “fact” that we have become a nation of “unwitting guinea pigs.”
Our exposure to chemicals is indeed extensive. Eat a bowl of chicken soup and hundreds of chemicals will flood your bloodstream. They include such delights as benzene, methanol, acetaldehyde and hydrogen sulfide, all of which are potentially “highly toxic.” Of course they are not toxic in the dose found in the soup. But should you look for them in the urine, thanks to our sophisticated analytical techniques, you will find them. Nobody bothers to look, because these chemicals are not deemed important, after all they are “natural,” and nobody has a political interest in banning chicken soup. But the story is different when it comes to synthetic compounds, especially those that have been deemed to be “endocrine disruptors.”
When I was alerted to a New York Times article featuring the headline “How Chemicals Affect Us,” I was pretty sure the columnist was not about to discuss how antibiotics cure infections, how preservatives protect us from eating moldy food or how detergents clean our clothes. I knew I’d be reading a litany of warnings about toxins, poisons and endocrine disruptors. Unfortunately, that’s what the term “chemical” has come to mean. To many, chemicals are the substances that insidiously invade our lives and shorten them.
The columnist was right about one thing. Chemicals do affect us! And they do so in every conceivable way! Take away oxygen and you die. Eat an improperly processed puffer fish, and the natural tetradotoxin it harbours will kill you. If you have headache, aspirin comes in handy. And yes, chemicals that leach out from plastics can have hormonal effects. But “hormonal effect” is not synonymous with “hormonal disruption.” An effect on a cell in the laboratory cannot be uncritically extrapolated to what may happen in a living body.
The problem is that the human body is very complex, and its interaction with the environment is virtually impossible to totally clarify. We are exposed to a vast array of compounds, and how they interact with each other and with the naturally occurring compounds in our body, defies analysis. One can take virtually any single compound, carry out animal studies with varying doses, and find something that can be used to raise alarm The bottom line is that nobody really “knows,” because the effects of trace chemicals cannot be teased out from the biological noise. This is especially the case for chemicals that mimic hormone activity. Is bisphenol A worse than soy? Do we stop drinking milk because it contains estrogens? Do we ban alfalfa sprouts because they contain coumestan, an estrogen mimic?
Critics who target one class of substances are unaware of the chemical complexity of life. Let’s try an analogy. Suppose you’re listening to a symphony orchestra and one string on a violin breaks. Do you think anyone would notice a difference in the sound? I doubt it. Similarly, removing one compound from the thousands and thousands to which we are exposed is unlikely to have a significant effect on life. Unlikely, but not impossible. Basically, both sides of the endocrine disruptor debate imply that they know more than they actually know, or indeed, what can be known.
A recent study by the Silent Spring Institute, a non-profit research organization, is a case in point. Researchers enlisted twenty people who volunteered to have the amount of bisphenol A and phthalates in their urine measured before and after a change in their diet. For three days they agreed to avoid all canned and packaged products and to build their diet around fresh, organic food. And guess what. After three days bisphenol A levels and phthalate levels in the subjects’ urine decreased by roughly 65 and 55% respectively. Wow! Looks like can decrease these “toxic” chemicals in your body dramatically after just three days by avoiding processed foods!
But wait a minute. It’s so easy to play with numbers. Want to increase your chance of winning the lottery by 100%? Sounds good? Just buy two tickets! Statistically you’ve doubled your chance, but does it matter? Doubling a very small number still leaves you with a very small number. Similarly, what does a 65% decrease mean if it is a decrease from a number that was tiny in the first place? And the amounts of BPA and phthalates were tiny. Way, way less than any regulatory limits. So what is the big deal about such a decrease?
In fact, what the results actually show is that these chemicals are cleared quickly from the body. But fear of these chemicals is not cleared quite so quickly. The stress caused to people by the constant harangue takes a toll on health, even though it cannot be measured the same way that levels of the chemicals in question can be measured in the urine.
Don’t get me wrong. I’m a big proponent of eating fresh, unprocessed foods, but more for the beneficial nutrients they contain than the “toxins” they elimininate. Remember, though, that chicken soup made with fresh vegetables and organic, free range chicken can still deluge the urine with plenty of compounds that could be vilified the same way as BPA or phthalates, if only one cared to make the effort. You put parsnips in your soup, don’t you? Well they contain psoralens, compounds that are not destroyed by cooking and have carcinogenic potential. But I’m not worried about the psoralens. Or about storing my left over soup in plastic containers. Why not? Because I look at numbers. And those numbers tell me that whatever “toxins” may be present are there at levels that way below what regulatory agencies find acceptable. I know how the scientists at Health Canada, FDA and EPA determine these levels. I know their qualifications and level of expertise. I also know the same for their critics. I know whom to trust.
Looking at the original New York Times article, I see the author refers to the chemistry industry as “Big Chem”, using this term in the same way as “Big Pharma” is used to demonise the pharmaceutical industry. I is a pity the reporter couldn’t have approached the subject in a more objective fashion.