Using hair straightening products can raise risk of cancer

By Pol Allingham via SWNS

Hair straightening products increase the risk of cancer, according to a “concerning” new study.

Scientists have warned that women who used straightening products more than four times in a year had over double the chance of developing the disease, compared to those who had not used the products in the last year.

There were no links between uterine cancer and other hair products such as dyes, bleaches, highlights or perms, according to the research.

Previous studies revealed the rate of uterine cancer was rising in the U.S, particularly among Black women, and the research team noted straightening products are most commonly used by that group.

Black women made up 60 percent of those who reported using the straighteners during the past year.

The relationship between using straighteners and developing cancer was not found to be different by race.

However, the team said there could be a greater impact on Black women because the products are more commonly used.

After following 33,497 women for 11 years the study found 1.64 percent of women who never used straighteners developed uterine cancer by the age of 70.

This went up to 4.05 percent in frequent users, worrying scientists at the National Institute of Environmental Health Sciences (NIEHS) in the United States..

Study author Dr. Che-Jung Chang, a research fellow at the NIEHS Epidemiology Branch said: “Because Black women use hair straightening or relaxer products more frequently and tend to initiate use at earlier ages than other races and ethnicities, these findings may be even more relevant for them.”

Lead author Dr. Alexandra White, head of the NIEHS Environment and Cancer Epidemiology group, said she was concerned by the “doubling rate” of cancer risk.

She said: “We estimated that 1.64 percent of women who never used hair straighteners would go on to develop uterine cancer by the age of 70; but for frequent users, that risk goes up to 4.05 percent.

“This doubling rate is concerning. However, it is important to put this information into context - uterine cancer is a relatively rare type of cancer.”

Around three percent of new cancer cases are uterine.

However, though it is relatively rare it is the most common cancer of the female reproductive system.

In 2022 there were 65,950 new cases of the disease, a number that has been increasing.

The findings of the study, published in the Journal of the National Cancer Institute, were consistent with previous investigations that revealed straighteners can increase the risk of hormone-related cancers in women.

The team did not collect information on brands and ingredients in the hair products used by the cohort.

However, they noted chemicals in straightening products could be behind the increased risk. These included parabens, bisphenol A, metals, and formaldehyde.

Chemical exposure from hair product use, particularly straighteners, may carry a greater concern because they are more easily absorbed through the scale.

This may be exacerbated by burns and lesions caused by straighteners.

The women in the study were aged 35 to 74.

Dr. White added: “To our knowledge, this is the first epidemiologic study that examined the relationship between straightener use and uterine cancer.

“More research is needed to confirm these findings in different populations, to determine if hair products contribute to health disparities in uterine cancer, and to identify the specific chemicals that may be increasing the risk of cancers in women.”

The same team discovered permanent hair dye and straighteners could increase the risk of breast and ovarian cancer.