Hair products may contain dangerous chemicals with endocrine-disrupting and carcinogenic properties. Previous studies have shown that its use is associated with an increased risk of hormone-sensitive cancers, such as breast and ovarian. However, the relationship with uterine cancer has not been investigated.
A study by the National Institute of Environmental Health Sciences and the University of North Carolina (USA), in which 30,000 women in the United States participated, managed to conclude that there is a relationship between these factors. The strength of the research is that it brought together people from different ethnic backgrounds: African American, Hispanic, Asian, and Native American. They were followed for 10 years,; in that time, 357 of them developed uterine cancer.
They calculated that 1.64% of those who never use hair straighteners would develop uterine cancer by age 70, but for those who use them frequently, the risk rises to 4.05%. An 80% higher adjusted risk of uterine cancer was found in those who had ever used this device in the previous 12 months.
Although African-American women are more likely to use hair relaxers, they are no more likely to develop uterine cancer than, for example, white or Latina women. However, those who start with this practice are younger.
This is a worrying increase for cancer that is still infrequently diagnosed but whence and associated mortality have increased over the last 20 years. More research is needed to confirm these findings in different populations, to determine whether hair products contribute to health disparities in uterine cancer, and to identify specific molecules that may increase this cancer risk in women.