If the results of a recent study are valid, the days of relaxing hair for Black women could be over. According to USA Today, Black women could develop uterine cancer from hair-straightening products with chemicals. "The National Institutes of Health research was part of the 50,000-population Sister Study, which examines risk factors for breast cancer and other health issues," the USA Today report said. "More than 34,000 women ages 35-74 participated in the research for nearly 11 years, during which time there were 378 uterine cancer diagnoses, according to the NIH." The Sister Study research was initially designed to find causes of breast cancer. "Women who reported using hair-straightening products – permanent processes like chemical relaxers, for example – more than four times in a year were more likely to get uterine cancer at some point than a person who didn’t use those products, according to the study."