Q. Are hair dyes safe? Can they cause cancer?
A. About one-third of all American women use permanent hair dyes, and through the years, there has been debate over whether the chemicals used in hair dye are carcinogenic. In particular, two compounds formerly used in dark hair dyes – 4 MMPD or 4 MMPD sulfate – were shown to cause tumors in laboratory animals.
Although manufacturers are no longer using these chemicals, there is concern that the new ones being used may pose potential problems because they have not undergone FDA testing. In fact, some consumer groups have been lobbying to have these chemicals banned until they have been thoroughly tested. Before you panic, however, I want to reassure you that two recent, large-scale studies have generally confirmed the safety of hair dyes. The first study, published in the Journal of the National Cancer Institute (May 1995), involved half a million women who use permanent hair dyes. Researchers found that even women who had used hair dyes for more than two decades did not have an increased risk of breast, stomach, lung, or other cancers. The only exception was that women who had used black hair dyes for more than 20 years had a slightly increased risk of non-Hodgkin’s lymphoma and multiple myeloma, two rare forms of cancer. Another study, which was published several months later (October 1995) In the Journal of the National Cancer institute, involved an investigation of about 100,000 registered nurses by researchers at the Harvard school of Public Health. Unlike the first study, the Nurses’ Study did not find any link between the use of hair dyes of any type and an increased risk of any forms of cancer.
Based on the studies, I think it is safe to assume that any hair dye on the market is safe to use. If you are still concerned about using any chemicals on your hair, I recommend that you ask your hairdresser about a natural product called henna, which is basically a vegetable dye. Henna can highlight hair and cover gray, but it is not permanent and it needs to be reapplied every six to eight weeks.
Marianne J. Legato, MD, Ph. D. (hon. c.), FACP is an internationally renowned academic, physician, author, lecturer, and pioneer in the field of gender-specific medicine. She is a Professor Emerita of Clinical Medicine at Columbia University College of Physicians & Surgeons and an Adjunct Professor of Medicine at Johns Hopkins Medical School. Dr. Legato is also the Director of the Foundation for Gender-Specific Medicine, which she founded in 2006 as a continuation of her work with The Partnership for Gender-Specific Medicine at Columbia University. She received an honorary PhD from the University of Panama in 2015 for her work on the differences between men and women.
At its core, gender-specific medicine is the science of how normal human biology differs between men and women and how the diagnosis and treatment of disease differs as a function of gender. Dr. Legato’s discoveries and those of her colleagues have led to a personalization of medicine that assists doctors worldwide in understanding the difference in normal function of men and women and in their sex-specific experiences of the same diseases.
She began her work in gender-specific medicine by authoring the first book on women and heart disease, The Female Heart: The Truth About Women and Coronary Artery Disease, which won the Blakeslee Award of the American Heart Association in 1992. Because of this research, the cardiovascular community began to include women in clinical trials affirming the fact that the risk factors, symptoms, and treatment of the same disease can be significantly different between the sexes. Convinced that the sex-specific differences in coronary artery disease were not unique, Dr. Legato began a wide-ranging survey of all medical specialties and in 2004, published the first textbook on gender-specific medicine, The Principles of Gender-Specific Medicine. The second edition appeared in 2010 and the third edition, dedicated to explaining how gender impacts biomedical investigation in the genomic era, won the PROSE Award in Clinical Medicine from the Association of American Publishers in 2018. A fourth edition is forthcoming.
She also founded the first scientific journals publishing new studies in the field, The Journal of Gender-Specific Medicine, and a newer version, Gender Medicine, both listed in the Index Medicus of the National Library of Medicine. She has founded a third peer-reviewed, open access journal, Gender and the Genome, which focuses on the impact of biological sex on technology and its effects on human life.
Dr. Legato is the author of multiple works, including: What Women Need to Know (Simon & Schuster, 1997), Eve’s Rib (Harmony Books, 2002), Why Men Never Remember and Women Never Forget (Rodale, 2005), Why Men Die First (Palgrave, 2008), The International Society for Gender Medicine: History and Highlights (Academic Press, 2017), and most recently, The Plasticity of Sex (Academic Press, 2020). Her books have been translated into 28 languages to date.
As an internationally respected authority on gender medicine, Dr. Legato has chaired symposia and made keynote addresses to world congresses in gender-specific medicine in Berlin, Israel, Italy, Japan, Panama, South Korea, Stockholm, and Vienna. In collaboration with the Menarini Foundation, she is co-chairing a symposium on epigenetics, Sex, Gender and Epigenetics: From Molecule to Bedside, to be held in Spring 2021 in Italy. She maintains one of the only gender-specific private practice in New York City, and she has earned recognition as one of the “Top Doctors in New York.”