August 31, 2014
Fear of Chemicals
Be Well

Fear of Chemicals

by John Swartzberg, M.D.  |  

When a reader recently wrote to us asking how much he should worry about the chemical dihydrogen monoxide (DHMO) in coffee and tea, I didn’t know whether he was serious or not. He pointed to the website, which lists dozens of dangers of this colorless, odorless chemical compound, starting with the fact that it’s a constituent of many toxic substances, disease-causing agents and environmental hazards (such as acid rain). It warns that DHMO kills thousands of people every year as a result of “accidental inhalation,” and that it can burn the skin, corrode (oxidize) metals and on and on.

This is a hoax, of course. Dihydrogen monoxide—meaning two hydrogen atoms and one oxygen atom—is an oddball chemical name for H2O, or water. I hadn’t heard about this spoof in many years. It seems to have originated in the 1990s with some students at UC Santa Cruz, though other sources have also been credited, and it has been extended over the years. It employs all the scare tactics typical of wacky health rumors, which can make even innocuous substances sound terrifying.

Over the years, quite a few people have taken the DHMO warning seriously, which is an indictment of the “chemophobia”—irrational fear of chemicals—that’s rampant these days. Clearly, that was one of the purposes of this hoax. Give something its chemical name and it sounds potentially toxic. But chemicals are the building blocks of the world. They are in every breath we take and every bite of food we eat. Plants and all living creatures are made of chemicals. There’s even a special name for plant chemicals—phytochemicals.

Many chemicals are essential for life (such as oxygen) or are lifesavers (antibiotics), while others can be deadly (carbon monoxide, cyanide). But the chemical world is not always black and white. Chemicals that are beneficial in tiny amounts are often dangerous in large ones. That’s why “the dose makes the poison” is a key principle of toxicology.

Similarly, while many people think that “natural” chemicals are more healthful and less risky than those made synthetically, the distinction is often a false one. Countless chemicals found in plants have been isolated by scientists and are now made in a lab or factory. For instance, the vitamin C found in an orange and the vitamin C made in a lab are exactly the same. The chemical that gives a banana its recognizable taste, called amyl acetate, can either be distilled from bananas (“natural banana flavor”) or manufactured using vinegar, alcohol and an acid (“artificial banana flavor”). Either way, it’s the same compound. Many important medicines are chemicals that were found in nature—salicylic acid (aspirin) from willow bark, paclitaxel (Taxol, a cancer drug) from the Pacific yew tree, digitalis (a heart drug) from the foxglove plant and quinine (a malaria drug) from the cinchona tree—and are now made synthetically.

On the other hand, many of the most dangerous chemicals, such as botulism toxin, are natural. Over the years, we’ve reported on various herbal remedies that contain potentially toxic compounds, the latest being ginkgo biloba.

Foods derived from plants contain amazing arrays of naturally occurring chemicals that scientists are still deciphering. A good example is coffee. Some of these phytochemicals are potentially healthful for humans, but others are potentially harmful. And then there’s the DHMO you add to all those coffee chemicals!