Scientific Proof Linking Hair Straightener Products to Cancers

Scientific Proof Linking Hair Straightener Products to Cancers

Do Hair Relaxers Cause Cancer?

People who use hair relaxers or hair straightener products regularly — at least four times per year — have a greater likelihood of significantly increasing the risk that they will be diagnosed with uterine cancer. The number of uterine cancer diagnoses continues to rise over the past several years, and based on several studies, researchers now suspect that hair relaxer use can increase the odds that women will develop uterine cancer.

In this article, we will review some of the most important scientific research that studied the link between hair straightener products and various cancers. If you are a frequent user of hair relaxer or straightening products, and you have been diagnosed with uterine cancer or another type of cancer that may be related to your product use, reach out to the hair relaxer lawyers at Lawsuit Legal News for latest hair straightener cancer lawsuit information and a free consultation.

Studies of Endocrine-Disrupting Chemicals Show Hair Relaxing Products Can Cause Uterine Cancer

In recent years, there has been growing concern surrounding the incidence of uterine cancer in the United States. Statistics reveal a troubling trend, with cases of uterine cancer on the rise, resulting in a projected 65,950 new cases and 12,550 deaths anticipated in 2022 alone. Uterine cancer is a malignancy that affects the uterus and often manifests through distressing symptoms like irregular vaginal bleeding, abdominal discomfort, and the presence of vaginal discharge.

The emergence of this cancer is closely tied to various risk factors, chief among them being prolonged exposure to excess estrogen and hormonal imbalances in the estrogen-progesterone equilibrium. One hypothesis posits that certain products containing endocrine-disrupting chemicals (EDCs) could disrupt hormonal processes, potentially leading to the development of uterine cancer.

Against this backdrop, the Journal of the National Cancer Institute (JNCI) initiated its inquiry, aiming to uncover any potential connections between the use of hair products and the incidence of uterine cancer.

In a groundbreaking study published in the Journal of the National Cancer Institute (JNCI), researchers have established a concerning connection between chemical hair relaxers and an elevated risk of uterine cancer. This comprehensive investigation drew upon data from the extensive Sister Study, which engaged over 30,000 women over an approximately eleven-year period.

The results of this study were alarming. It revealed that individuals who regularly used hair relaxers faced a significantly higher likelihood of developing uterine cancer. Additionally, the study highlighted a particularly concerning trend: black women, who were more likely to begin using hair relaxers at a young age, were identified as a group facing a heightened risk of uterine cancer.

Specifically, participants in the study who did not consistently use hair relaxers had an approximate 1.64% likelihood of developing uterine cancer by the age of 70. However, those who did use hair relaxers at least four times a year showed a significantly elevated 4.80% risk of developing uterine cancer by the same age milestone. Notably, the study did not establish a clear correlation between uterine cancer and the use of other hair products, distinguishing the unique risk associated with hair relaxers.

Among the participants, there were 378 confirmed cases of uterine cancer, and hair-straightening product usage emerged as a notable risk factor. At Lawsuit Legal News we understand that a uterine cancer diagnosis often comes at a steep financial cost for these individuals and we’re here to help.

The Sister Study Unveils Disturbing Findings About Hair Straightener Products

The Sister Study, spearheaded by the National Institutes of Health, closely monitored 33,497 women aged between 35 and 74. Among this cohort study, those who reported frequent use of hair straightening products (utilized at least four times within the previous year) were found to be approximately twice as likely to develop uterine cancer when compared to women who didn’t use these products.

Uterine cancer is usually a relatively small fraction of cancer diagnoses, accounting for just 3.4 percent of newly diagnosed cancer cases each year. Nevertheless, the incidence of uterine cancer has been on the rise across the United States in recent years. This is particularly concerning for Black women, who bear a disproportionate burden, experiencing twice the mortality rate from uterine cancer compared to other ethnic groups.

While The Sister Study originally aimed to assess breast cancer risk among women with sisters who had previously battled cancer, its long-term monitoring capability allowed it to uncover various other potential health concerns, including the risk of developing cancers like uterine cancer. This extensive research initiative studied the interplay between genetics and lifestyle factors, with the ultimate goal of reducing breast cancer diagnoses and improving outcomes for breast cancer patients. It also offered valuable insights into the environmental factors contributing to other types of cancer.

Who Were The Participants of The Sister Study?

The Sister Study, conducted with the National Institute of Environmental Health Sciences, rallied over 50,000 women to share vital medical and lifestyle information, with a specific focus on unraveling the development of hormone-sensitive cancers. All participants in this endeavor were cancer-free women aged 35 to 74 residing in the United States who had at least one sister with a history of breast cancer diagnosis.

The Journal of the National Cancer Institute (JNCI) seized upon the data furnished by The Sister Study to embark on its investigation into uterine cancer induced by hair relaxer products. This collaborative effort involved a cohort study of 33,947 women who were actively enrolled in The Sister Study. Within this group, the women fell into these categories:

  • 85.6% were non-Hispanic/White, 
  • 7.4% identified as Black/African American, 
  • 4.4% were of Hispanic/Latina non-Black origin, and 
  • 3.5% represented other racial or ethnic backgrounds.

How Were Participants Evaluated for Uterine Cancer Linked to Hair Straightener Products?

At the outset of this study, each participant completed a comprehensive questionnaire to assess their usage of various hair products. Participants were asked to disclose whether they had consistently used hair products like hair dyes, bleach, highlights, pressers, relaxers, or straighteners over the preceding twelve months.

Responses ranged from not using any hair products to employing them consistently every few weeks. Additionally, participants were required to report any instances of nonprofessional application of hair dye, straighteners, or relaxers.

Several key pieces of information were also gathered for the study, including:

  • Height
  • Body mass index
  • Age
  • Race and ethnicity
  • Physical activity level
  • Smoking habits
  • Alcohol consumption patterns
  • Educational background
  • Work history within beauty salons

Participants received annual follow-ups, during which they reported any health changes or potential cancer developments. More thorough assessments occurred every two to three years. This data collection was instrumental in establishing whether the use of hair relaxers had any association with the development of uterine cancer.

The Study Uncovered 378 Confirmed Uterine Cancer Cases

Over an approximately eleven-year span, the Sister Study revealed a total of 378 cases of uterine cancer among its participants. These cases encompassed various types of uterine cancer, including endometrial cancer, uterine sarcoma, and other forms affecting the uterus. The diagnosis of uterine cancer was confirmed through meticulous scrutiny of each woman's medical records or official death certificates where uterine cancer was established as the underlying cause of death.

Participants self-reported 109 cases of uterine cancer that could not be documented. Out of 262 confirmed uterine cancer diagnoses, 94.7% were determined to be type one or type two endometrial cancer. These types are differentiated by hormone sensitivity and how clinically aggressive the cancer was.

Based on the scientific proof that hair straightening products are linked to several types of cancers, the team at Lawsuit Legal News strongly believes that cancer sufferers who bring legal action for their damages will receive fair compensation. Our team of legal professionals works with cancer patients to prove the cause of their conditions and hold the corporate manufacturers of dangerous products responsible.

Call us at 866-467-0943 or fill out our online contact form for a free consultation to learn more about your legal rights to bring a claim for compensation based on your use of these hair relaxer products.


Matthew Dolman

Personal Injury Lawyer

This article was written and reviewed by Matthew Dolman. Matt has been a practicing civil trial, personal injury, products liability, and mass tort lawyer since 2004. He has represented over 11,000 injury victims and has served as lead counsel in over 1000 lawsuits. Matt is a lifetime member of the Million Dollar Advocates Forum and Multi-Million Dollar Advocates Forum for resolving individual cases in excess of $1 million and $2 million, respectively. He has also been selected by his colleagues as a Florida Superlawyer and as a member of Florida’s Legal Elite on multiple occasions. Further, Matt has been quoted in the media numerous times and is a sought-after speaker on a variety of legal issues and topics.

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