Will dyeing hair cause cancer? More and more studies have found that the risk of these cancers will increase

Daily chemicals such as hair dyes that can change the color of the hair are very common in daily life

Many middle-aged and elderly people regularly dye their hair black in order to cover up their gray hair and look young; there are also many young people who dye their hair in other colors or even "colorful" for the sake of fashion, coolness, handsomeness, and beauty

According to the durability of dyeing, hair dyes can be divided into temporary, semi-permanent and permanent

Among them, permanent hair dyes are the most widely used hair dyes because they can last longer and are more convenient

However, because the hair dye contains a lot of chemicals, will it increase health risks, especially cancer risks? This has also aroused people's attention and worries

For example, most hair dyes contain p-phenylenediamine, which is a substance included in the list of carcinogens by the International Agency for Research on Cancer (IARC).

At the same time, with the development of more research, scientists have discovered that the use of hair dye may be associated with an increased risk of a variety of cancers

May increase the risk of prostate cancer in men

Recently, a study published in the well-known journal Cancer of the American Cancer Society (ACS) showed that the use of oxidative permanent hair dyes is associated with an increased risk of prostate cancer in men

Oxidative permanent hair dye is the main type of permanent hair dye, and most people use this

In this study, scientists analyzed data from 28,795 people in the Finnish ATBC study

During an average follow-up of 28 years, a total of 2,703 people developed prostate cancer

After removing the influence of many factors such as age, life>

Compared with people who did not use oxidative permanent hair dye, the use of this hair dye was associated with a 77% increase in the risk of prostate cancer; it was associated with a 179% increase in the risk of early prostate cancer; and it was associated with a 66% increase in the risk of advanced prostate cancer.

At the same time, the results also show that the use of oxidative permanent hair dyes on the increased risk of prostate cancer is more pronounced in people with a shorter smoking age and a higher body mass index (BMI)

Scientists have analyzed that oxidized permanent hair dyes contain a variety of substances that may increase the risk of prostate cancer, such as benzidine, 4-aminobiphenyl and 2-naphthylamine

May increase breast cancer risk in women

In 2019, a study published in the International Journal of Cancer found that the use of permanent hair dyes and hair straighteners was associated with an increased risk of breast cancer in women

In this study, scientists from the National Institutes of Health (NIH) analyzed data from a total of 46,709 women in the "sister study".
They were all 35 to 74 years old, and all of them had breast cancer.
Sister, but I don’t have breast cancer
.

During an average follow-up of 8.
3 years, a total of 2,794 women developed breast cancer
.

After removing the influence of other factors, the results of the study showed that compared with women who did not use hair dye, women who used permanent hair dye within 1 year had a 9% higher risk of breast cancer
.

The use of temporary and semi-permanent hair dyes is not significantly associated with breast cancer risk
.

In addition, research results also show that the use of chemical hair straighteners is also associated with an increased risk of breast cancer
.
Among all women, women who used hair straighteners increased their breast cancer risk by an average of 18%
.
As the frequency of use increases, the risk is higher.
Women who use hair straighteners at least once every 5-8 weeks have a 30% increase in breast cancer risk
.

May increase the risk of multiple types of cancer in women

In 2020, a study published in the British Medical Journal (BMJ) further found that the use of permanent hair dyes may increase the incidence of basal cell carcinoma, ovarian cancer, Hodgkin’s lymphoma and more in women to varying degrees.
Kind of breast cancer risk
.

In this study, scientists from Harvard Medical School's Brigham and Women's Hospital (Brigham and Women's Hospital) and other institutions analyzed the data of 117,000 women from the National Nurses Health Study (NHS), their age ranged from 30 to 30 years.
55 years old
.

During an average follow-up of 36 years, there were 20,805 new cases of solid cancer (excluding non-melanoma skin cancer), 1807 cases of blood system cancer, 22560 cases of basal cell carcinoma, and 2792 cases of skin squamous cell carcinoma
.
In addition, 4860 cancer-related deaths occurred
.

After removing the influence of other factors, the results of the study show that compared with women who have never used permanent hair dye, there is no obvious association between using permanent hair dye and the risk of most cancers, but it is associated with some cancer risks.
Elevated related
.

Specifically, the use of permanent hair dyes is significantly associated with the increased risk of certain breast cancers (including estrogen receptor negative, progesterone receptor negative and hormone receptor negative breast cancer) and ovarian cancer, and with the use of As the frequency increases, the risk of cancer will also increase
.

At the same time, the effect of permanent hair dye on cancer risk is also related to natural hair color
.

For example, the use of permanent hair dyes is associated with a slight increase in the risk of skin basal cell carcinoma, but in people with light natural hair (golden or light brown), this risk is higher; it is also associated with Hodgkin’s lymphoma The increased risk is related, but this phenomenon is only observed in people with dark natural hair colors (brown, black, and red)
.

summary

It should be noted that the three studies mentioned above are observational studies, which only show that the use of permanent hair dye or hair straightener is associated with an increased risk of certain types of cancer, and does not indicate a causal relationship
.

Moreover, with these findings, is it not recommended to dye hair again? Scientists remain cautious
.

However, they believe that although it is not yet possible to draw a definitive conclusion on whether the hair dye will cause cancer
.
But based on some research evidence, everyone should at least be aware that hair dyes may have a risk of cancer
.
Especially those who like to use permanent hair dye, and those who use hair dye frequently, should pay attention to it
.

Reference

[1] Jung-Eun Lim, et al.
,(2021).
Hair dye use and prostate cancer risk: A prospective analysis in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study cohort.
Cancer, DOI: 10.
1002/cncr.
34035 .

[2] Yin Zhang, et al.
,(2020).
Personal use of permanent hair dyes and cancer risk and mortality in US women: prospective cohort study.
BMJ, DOI: https ：//doi.
org/10.
1136/bmj.
m2942 .

[3] Carolyn E.
Eberle, et al.
, (2019).
Hair dye and chemical straightener use and breast cancer risk in a large US population of black and white women.
International Journal of Cancer, DOI: 10.
1002/ijc.
32738