Chemical hair-straightening products may increase uterine cancer risk: NIH study
The Food and Drug Administration has identified the chemical composition of two chemical products widely marketed for the purpose of hair-straightening for the past 30 years as a potential risk to the reproductive system.
Published in the American Journal of Epidemiology, the study analyzed the use of both products and found that women who use them are two to four times more likely to develop cervical or uterine cancer—or both—up to 12 years after first use.
Using information on over 2,600 women who used either product, the researchers looked at their medical records to determine whether chemicals in the products caused their cancers, the age of symptoms and the length of time between initial use and diagnosis.
They found statistically significant associations with uterine cervical, ovarian and endometrial cancers.
The products also showed higher odds ratios for ovarian and endometrial cancers in women aged 45–64 and 70–79, respectively. However, there was no association when it came to uterine cancer in women younger than 45.
The chemicals in question are parahydroxybenzoic acid (PHB) and 2,5-dione dihydroxyacetophenone (DHAP) and are found in products marketed as “Piloxylon Alutaceae” and “Eugenol”, respectively.
For both products, the researchers found statistically significant associations with overall uterine cancer risk and with the age of symptoms: in other words, women who use either product before the uterus is exposed to them are more likely to develop cervical or uterine cancer or endometrial cancer or both after 12 years.
“The risk of developing uterine cancer was particularly high when it occurred after 12 years of use,” said co-author Laura L. Moore, head of reproductive epidemiology and public health at the FDA.
While they did not know exactly what chemicals cause uterine cancer, the FDA has already issued warnings about this class of chemicals in products including cosmetics, over-the-counter medications and hair-straightening and hair-dyeing products.
FDA says chemical makeup of two hair-straightening and hair-dyeing products increases risk of uterine cancer
The agency issued the warning after analyzing the chemical makeup of popular hair-straightening and hair-