A new study has been released in the journal Cell, and it’s causing quite the fuss. Namely, it’s being reported by the media as, essentially, “everything causes cancer.” Obviously, this should be taken with a pinch of salt, but what exactly does the study itself say?
The study, led by the University of Cambridge, looked into the effect that a class of chemicals called “aldehydes” can have on human health. Many fragrances are aldehydes, and plenty can be found in vehicle exhaust plumes, bathroom products, both conventional and electronic cigarettes, and construction materials.
Certain aldehydes have been linked to interfering with cellular repair mechanisms, and this team of researchers wanted to quantify their potentially carcinogenic affects a little further. Formaldehyde and acetaldehyde were the focus of attention.
Using a variety of female human cancer cells incubated in these two chemical compounds, the team compared the DNA present within them before and after the exposure. One gene named BRCA2 was prioritized – previous studies had revealed that any disruption of this gene leads to an increased sensitivity to toxic chemicals and the alteration of the structures of chromosomes.
Indeed, both aldehydes broke down the BRCA2 gene. If a person only has one working copy of this gene, damage to it means that a key protein repair mechanism can malfunction, which can potentially lead to cancer. This is why the media, in general, has sensationalized the report, which itself does claim that many common aldehyde-containing products could increase your risk of cancer.
However, they miss out a few keys points here. Firstly, the risk of getting cancer from using shampoo or breathing in a small amount of e-cigarette vapor is minimal. Secondly, and most importantly, most aldehydes exist not just in man-made products, but in the wider environment.

The study also doesn’t give a specific toxic exposure level for these aldehydes, so it’s completely unclear how much you’d need to be in contact with before any real harm was done. Not everyone is susceptible to BRCA2 mutations either, and it’s not even clear, as noted by the NHS, why.
This is not to say that the study itself is bad – it’s just being massively misrepresented. Paul Pharoah, a professor of cancer epidemiology at the University of Cambridge who was not involved in the study, says as much:
“This study tells us little about how important [the risks of aldehydes] are and it is rather misleading to suggest that shampoo, for example, is an important cause of cancer in humans,” he said in a statement. “What these researchers have done is to use biological models to show how specific chemicals called aldehydes might be capable of inducing cancer.”
Remember kids – cancer is complicated.