Hair product use, age at menarche and mammographic breast density in multiethnic urban women

Abstract

BackgroundSelect hair products contain endocrine disrupting chemicals (EDCs) that may affect breast cancer risk. We hypothesize that, if EDCs are related to breast cancer risk, then they may also affect two important breast cancer risk factors: age at menarche and mammographic breast density.MethodsIn two urban female cohorts (N = 248): 1) the New York site of the National Collaborative Perinatal Project and 2) the New York City Multiethnic Breast Cancer Project, we measured childhood and adult use of hair oils, lotions, leave-in conditioners, root stimulators, perms/relaxers, and hair dyes using the same validated questionnaire. We used multivariable relative risk regression models to examine the association between childhood hair product use and early age at menarche (defined as <11 years of age) and multivariable linear regression models to examine the association between childhood and adult hair product use and adult mammographic breast density.ResultsEarly menarche was associated with ever use of childhood hair products (RR 2.3, 95% CI 1.1, 4.8) and hair oil use (RR 2.5, 95% CI 1.2, 5.2); however, additional adjustment for race/ethnicity, attenuated associations (hair products RR 1.8, 95% CI 0.8, 4.1; hair oil use RR 2.3, 95% CI 1.0, 5.5). Breast density was not associated with adult or childhood hair product or hair oil use.ConclusionsIf confirmed in larger prospective studies, these data suggest that exposure to EDCs through hair products in early life may affect breast cancer risk by altering timing of menarche, and may operate through a mechanism distinct from breast density.

A Systematic Literature Review of Factors Affecting the Timing of Menarche: The Potential for Climate Change to Impact Women’s Health

“…McDonald et al found that increases in EDCs have been implicated in early menarche [59]. However, their study investigated EDCs in hair oils and hair products [59], which are likely somewhat different from the EDCs found in oil and gas wastewater. However, if the mechanism affecting age at menarche is the EDCs as proposed, then the specific chemical should not matter as long as endocrine disruption is taking place [177].…”

“…Another study investigating the effects of breast cancer incidence and atomic bomb survivors in Japan and its relationship to timing of menarche found that the breast cancer incidence due to radiation was high regardless of the stage of the breast's differentiation, indicating that radiation exposure itself maybe a breast carcinogen [58]. Exposure to endocrine-disrupting chemicals [59] and hair products [59], and in utero exposure to atrazine [60] were all associated with early menarche ( Figure 3A). On the other hand, in utero exposure to organochlorine did not appear to alter the timing of menarche [61].…”

“…A study found that endocrine-disrupting chemicals (EDCs) were found in the surface water near an oil and gas wastewater disposal site [176]. McDonald et al found that increases in EDCs have been implicated in early menarche [59]. However, their study investigated EDCs in hair oils and hair products [59], which are likely somewhat different from the EDCs found in oil and gas wastewater.…”

Analysis of Breast Cancer Cases According to County-Level Poverty Status in 3.5 Million Rural Women Who Participated in a Breast Cancer Screening Program of Hunan Province, China from 2016–2018

“…Early age at menarche is associated with an increased risk of breast cancer 25 26 . Thereafter, age at menarche (> 13 years compared with < 13 years) was not the risk factor when adjusted all the variables that there were differences in the single logistic regression analysis in our study.…”

Correction to: Early-life exposure to PM2.5 and risk of acute asthma clinical encounters among children in Massachusetts: a case-crossover analysis

“…After publication of the article [ 1 ], it was brought to our attention that a number in Table 1 is incorrect. The table quotes the number of children with Maternal Language Preference listed as “Other” as being “240 (0.7%)”.…”