Hair Dye and Relaxer Use among Cisgender Women in Embu and Nakuru Counties, Kenya: Associations with Perceived Risk of Breast Cancer and Other Health Effects

Abstract

Despite widespread use of hair products globally, little is known about the prevalence and patterns of use in populations outside the United States. As some hair products contain endocrine-disrupting chemicals (EDCs) and EDCs have been linked to breast cancer, which is increasing globally, in this study, we addressed key knowledge gaps about hair product use and practices, and perceptions of use among women in two counties in Kenya. Using community-engaged approaches in Embu and Nakuru, Kenya, we recruited women aged 15-50 years to complete a questionnaire that ascertained hair product use in the last 7-14 days, ever using hair dyes and chemical relaxers, and participants' perceptions or harm around hair product use. In multivariable-adjusted regression models, we evaluated associations between participants' sociodemographic characteristics and perceptions of hair product use in relation to if they have ever used hair dyes and relaxers. In our sample of 746 women (mean age, 30.4 ± 8.1 years), approximately one-third of participants reported ever using permanent and/or semi-permanent hair dyes, with approximately one-fifth reporting current use. Almost 60% reported ever using chemical relaxers, with a little over one-third reporting current use. Increasing age and having an occupation in the sales and service industry were statistically significant predictors of hair dye use (OR 1.04, 95% CI: 1.02-1.06 and OR 2.05, 95% CI: 1.38-3.03, respectively) and relaxer use (OR 1.03, 95% CI: 1.01-1.06 and OR 1.93, 95% CI: 1.30-2.87). On average, participants reported moderate-to-high levels of concern about exposures and general health effects from using hair products, and relatively high levels of perceived risk of breast cancer related to hair product use. However, in contrast to our hypotheses, we observed mixed evidence regarding whether higher levels of perceived risk were associated with lower odds of ever using hair dyes and relaxers. These findings add new knowledge to the extant literature on hair product use among women in Kenya, where breast cancer incidence rates are increasing. Improving the understanding of patterns of use of specific products and their chemical ingredients-which may be hormone disruptors or carcinogens-and exploring the role of environmental health literacy are critical for developing interventions to reduce potentially harmful exposures found in these products.

Keywords: Kenya; chemical relaxers; cisgender women; hair dyes; hair products; perceived breast cancer risk; perceived health risks.

Figure 1

Perceptions about health effects and perceived breast cancer risk related to hair product use among female study participants in Kenya, overall and stratified by county. Stacked bar charts were used to visually depict the percentage of female study participants who strongly agree, agree, neither agree nor disagree, disagree, or strongly disagree with (i) perceptions about health effects related to hair product use (6 items) and (ii) perceived breast cancer risk related to hair product use (6 items), in the overall sample and stratified by county (Embu vs. Nakuru). The two-sided Chi-Squared test was used to assess differences in study participants’ 5-point Likert scale responses across counties. The Benjamini-Hochberg (BH) approach was employed to correct for multiple comparisons, using a False Discovery Rate (FDR) of 0.05. * Differences in participant responses across counties for the following perception items (marked with an asterisk) remained statistically significant after B-H correction: “The personal hair care products I use affect my health” (p < 0.001), “Government agencies in Kenya do a good job of regulating personal care products to ensure they are safe for consumers” (p < 0.001), and “I am concerned that the labels of hair care products do NOT list all the ingredients” (p = 0.008).

Figure 2

Adjusted odds ratios and 95% confidence intervals illustrating the associations between perceptions about health effects and perceived breast cancer risk and ever use of hair dyes among women in Kenya, overall and stratified by county. Independent multivariable-adjusted logistic regression models were run with robust error variances to examine the association between perceptions about health effects and perceived breast cancer risk related to hair product use (strongly agree/strongly disagree to a perception vs. all other responses) with regular ever hair dye use, overall and stratified by county (Embu vs. Nakuru). Regular ever hair dye use is defined as the use of permanent and/or semi-permanent hair dye(s) more than two times per year for ≥1 year. Each logistic regression model adjusted for relevant sociodemographic (age, education level, current occupation field, number of children under age 15 residing in household) and health history (age at menarche) characteristics. Associations were reported as adjusted odds ratios (ORs) and plotted as adjusted log odds ratios (log ORs), accompanied by their corresponding 95% confidence intervals (CIs). The Benjamini-Hochberg (B-H) approach was employed to correct for multiple comparisons, using a False Discovery Rate (FDR) of 0.05. Following B-H correction, associations with p-values ≤0.002 (marked with an asterisk) remained statistically significant.

Figure 3

Adjusted odds ratios and 95% confidence intervals illustrating the associations between perceptions about health effects and perceived breast cancer risk and ever use of relaxers among women in Kenya, overall and stratified by county. Independent multivariable-adjusted logistic regression models were run with robust error variances to examine the association between perceptions about health effects and perceived breast cancer risk related to hair product use (strongly agree/strongly disagree to a perception vs. all other responses) with regular ever relaxer use, overall and stratified by county (Embu vs. Nakuru). Regular ever relaxer use is defined as the use of chemical relaxer(s) or straightening product(s) more than two times per year for ≥1 year. Each logistic regression model adjusted for relevant sociodemographic (age, education level, current occupation field, number of children under age 15 residing in household) and health history (age at menarche) characteristics. Associations were reported as adjusted odds ratios (ORs) and plotted as adjusted log odds ratios (log ORs), accompanied by their corresponding 95% confidence intervals (CIs). The Benjamini-Hochberg (B-H) approach was employed to correct for multiple comparisons, using a False Discovery Rate (FDR) of 0.05. Following B-H correction, associations with p-values ≤0.002 would be statistically significant, but none were.