Formaldehyde, a toxin and carcinogen found in construction materials, carpets, car exhaust, cigarette smoke and even permanent press clothing, turns out to play an important role in the body — one that may explain why the chemical causes cancer.
In a study published this month in the journal Science, researchers from the University of California, Berkeley, and the University of Oxford in the United Kingdom reported that formaldehyde is an inhibitor of DNA methylation, the enzymatic attachment of a methyl (CH3) group to DNA, which is one of the body's most common epigenetic ways of turning genes off or on.
The study provides the first evidence that formaldehyde, which scientists only recently discovered is made by the body in small quantities, is actually used by the body to regulate epigenetic change, and it suggests that, in excess, it may suppress the body's attempts to prevent the expression or overexpression of certain genes.
Previous research demonstrated that formaldehyde in very large quantities disables DNA by causing crosslinks, but it didn't explain the toxicity of small amounts of formaldehyde.
"People haven't looked for formaldehyde inside the body because they just think about the environmental consequences of formaldehyde. But it's naturally made inside each and every one of our cells," said the study's senior author, Christopher Chang, UC Berkeley professor of chemistry and of molecular and cell biology. "The broader implication of our study is that it provides a biochemical mechanism for how formaldehyde might be a carcinogen. We know smoking's bad for you, and pollution is bad for you, in part because of the formaldehyde. We showed that if you alter your body’s internal formaldehyde levels, that can also change your epigenetics, which then can reprogram cancer."