echemi logo
Product
  • Product
  • Supplier
  • Inquiry
    Home > Biochemistry News > Biotechnology News > A 36-year study from Harvard University tells you: Does dyeing your hair cause cancer?

    A 36-year study from Harvard University tells you: Does dyeing your hair cause cancer?

    • Last Update: 2021-10-21
    • Source: Internet
    • Author: User
    Search more information of high quality chemicals, good prices and reliable suppliers, visit www.echemi.com

    Young people pursue fashion, like trends, and like to dye their hair brightly
    .


    There are also more and more elderly people falling in love with hair dyeing, mostly to cover up the traces of time


    But is dyed hair really healthy?

     

    1.


    Hair dyeing causes cancer? Harvard University conducted a large-scale study

    In order to explore the impact of hair dyeing on cancer, Harvard Medical School’s Brigham and Women’s Hospital and the Dana-Farber Cancer Institute jointly analyzed and discussed data from the American Nurses’ Health Study, and published the results in the well-known journal "British Medical Journal
    .


    "

     

     

    The data covers approximately 120,000 female subjects between the ages of 30 and 55
    .

    The researchers analyzed the subjects' height and weight, race, smoking and drinking status, natural hair color, family history of cancer, menopausal status, etc.
    , and collected information on their use of permanent hair dyes and cancer incidence and mortality
    .

     

    Researchers follow up the subjects every two or four years and update relevant information in a timely manner
    .


    After 36 years of follow-up investigation, the researchers came to the following conclusions:

    Conclusion 1:

    After adjusting for other factors, they found that compared with women who have never used permanent hair dye, women who have used permanent hair dye suffer from most cancers (including kidney cancer, brain cancer, certain breast cancers, etc.
    ) The risk will not increase
    .


    No significant association was found in cancer-related deaths


    Conclusion 2:

    However, in a small number of cancers, the use of permanent hair dyes is associated with an increased risk of certain breast and ovarian cancers, and the more often they are used, the higher the risk
    .

    Conclusion 3:

    Of the 120,000 subjects, 38,000 had used permanent hair dye, and they were more likely to smoke and drink
    .

    However, the researchers also emphasized that although this study has some findings, it is ultimately an observational study, and its causality cannot be determined
    .


    This study also has limitations


    2.


    However, since the 1980s, people have re-studied hair dyes and found that bacteria do mutate when they come into contact with hair dyes
    .


    When they are used in animal fur, they are not carcinogenic


    The World Health Organization lists hair dyes as a "third-level carcinogen", which means that the carcinogenicity to humans cannot be classified and is the same as the carcinogenicity of coffee
    .

    Overall, still a lack of large-scale studies to confirm "hair dyes are carcinogenic"
    .


    People's perception of hair dye may be a misunderstanding


    3.


    1) Allergies

    The use of hair dyes is prone to allergic problems, especially inferior hair dyes, which are manifested as redness, itching, shedding, etc.
    , and even scalp and facial edema
    .


    In addition, hair dyes may also cause allergic reactions during bathing
    .

    If the allergy is severe or persistent, see a dermatologist
    .

    2) Liver damage

    Certain chemical components in hair dyes have been proven to cause drug-induced liver damage
    .
    The frequency of hair dye use and product quality are also factors that cause liver damage
    .
    In particular, long-term use of low-quality hair dyes may cause greater damage to the liver
    .

    3) Kidney damage

    Common anti-inflammatory and analgesic drugs, some Chinese herbal medicines, and folk prescriptions all have nephrotoxicity, and long-term or large amounts can damage kidney health
    .
    In addition, whitening products commonly used by women and low-quality hair dyes commonly used by young people may affect kidney health
    .

    4) Heavy metals

    Hair dyes produced by regular channels and manufacturers are allowed to contain a certain amount of lead, mercury and arsenic, but the content is very low and has no effect on human health
    .
    Inferior hair dyes mostly have the problem of excessive lead content
    .
    Long-term use may cause chronic lead poisoning
    .

    4.
    Color your hair safely, remember four suggestions

    1) Purchase qualified hair dye

    Regular and qualified hair dyes are less irritating and no harmful substances exceed the standard
    .
    Therefore, before dyeing your hair, you must confirm that the hair dye used is produced by a regular manufacturer, has been audited, and has an exclusive production batch number and approval number
    .

    2) Do an allergy test

    It is best to perform an allergy test before dyeing your hair
    .
    Apply a small amount of hair dye behind the ears or inside the wrists and observe for 2-4 days to see if there are skin redness, itching, rashes and other problems
    .
    If not, you can use hair dye
    .

    3) Twice a year, wash more

    Try to dye your hair as little as possible
    .
    If you really want to dye your hair, you should also control the frequency of dyeing your hair
    .
    It is recommended not to exceed twice a year
    .
    In addition, avoid leaving the hair dye on the scalp for a long time, and wash your hair frequently after dyeing your hair
    .

    4) These people need attention

    People with allergic diseases, pregnant women, breastfeeding women and children should try not to dye their hair
    .

    In general, although "hair dyeing causes cancer" is still uncertain, long-term frequent hair dyeing does affect health
    .
    However, health experts remind everyone who loves beauty not to dye their hair frequently
    .
    When dyeing your hair, you should choose a qualified hair dye and be responsible for your own health
    .

     

    This article is an English version of an article which is originally in the Chinese language on echemi.com and is provided for information purposes only. This website makes no representation or warranty of any kind, either expressed or implied, as to the accuracy, completeness ownership or reliability of the article or any translations thereof. If you have any concerns or complaints relating to the article, please send an email, providing a detailed description of the concern or complaint, to service@echemi.com. A staff member will contact you within 5 working days. Once verified, infringing content will be removed immediately.

    Contact Us

    The source of this page with content of products and services is from Internet, which doesn't represent ECHEMI's opinion. If you have any queries, please write to service@echemi.com. It will be replied within 5 days.

    Moreover, if you find any instances of plagiarism from the page, please send email to service@echemi.com with relevant evidence.