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    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
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    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

    .
    For example, the research subjects are mostly white women, lacking in ethnic diversity, and some unpredictable factors may cause bias in the research results

    .

    2.
    "Hair dyeing causes cancer" or misunderstanding

    "Whether hair dyes cause cancer" has always been controversial
    .
    In the last century, there were documents that pointed out the correlation between hair dyes and hematological tumors

    .
    Carcinogens were also found in some hair dyes .

    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

    .
    In addition, the researchers conducted statistics on the incidence of tumors and population exposure after using hair dyes, and found that the incidence of tumors did not increase

    .

    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.
    Health risks still exist

    Although there is no strong link between hair dye and cancer, four main problems that hair dye may cause are still worthy of our attention
    .

    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

    .

     

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