Hair dyeing has become an indispensable way for beauty lovers. However, in recent years, it is often exposed that “hair dye causes cancer” and “hair dye master’s hand suffers from skin cancer”. Which is true or false? Let’s get to know it!
how carcinogenic are hair dyes? Peking University Cancer Hospital conducted a study on the carcinogenic factors of lymphatic cancer. The study found that women who dyed their hair more than 8 times a year for more than 25 years had a risk of developing lymphatic cancer more than twice as high as that of normal people. People who use permanent hair dyes, in particular, are more likely to develop cancer than other types of hair dyes.
when we go to the hair salon, the hair stylist will ask you which brand you want to use or which color you want to dye, but in fact, there are three categories of hair dyes: temporary hair dyes, semi permanent hair dyes and permanent hair dyes.
permanent hair dye: chemical synthetic hair dye is often used in permanent hair dyeing. Dye molecules will directly enter the hair cortex, and the macromolecular pigment formed is fixed in the inner hair cortex. Permanent hair dyes to maintain durability, the chemical reaction will be more intense than the other two types of hair dyes, hair will harden and dry. At the same time, the dye molecules are sealed in the hair fiber, which is not easy to be washed, and has a long retention time in the body, which is easy to produce long-term impact and damage. Of course, the benefits are also more obvious, dyeing the longest time.
semi permanent hair dye: the dye particles of semi permanent hair dyes are smaller, they will hang in the gap between hair scales, but they can not penetrate into the hair interior, only penetrate into the hair epidermis, and the color persistence can last for 6-12 times before fading. No need to use hydrogen peroxide, less toxic than permanent dyeing. Semi permanent hair dye is usually made into shampoo.
temporary hair dyeing: temporary hair dyeing, that is, one-time hair dyeing, can be removed by washing one’s hair. The dye particles used in disposable hair dye are very large, and it is impossible to enter the hair. It is usually used by pressure tank spray, forming a layer of colored film on the hair surface.
although permanent hair dyes are the most lasting, they do the most “deep” harm to us. Experts said that the reason why hair dyes cause cancer is that permanent hair dyes contain carcinogens such as hydrogen peroxide and p-phenylenediamine. Among them, p-phenylenediamine is a strong stimulant. After being heated, it will directly enter the capillaries through the scalp, and enter the human bone marrow with the blood circulation, acting on the cells in the body, thus inducing cancer. The higher the color retention of hair dyes, the higher the concentration of chemicals added.
in 2017, a research report was published in the journal. The report found that the risk of breast cancer and estrogen receptor positive breast cancer increased by 1.51 times and 1.72 times respectively for those who used dark hair dyes. The risk of estrogen receptor positive breast cancer increased by 1.36 times for those with high use rate.
hair loss: after hair dyeing, the cortical layer of hair will also be damaged. The disulfide bond formed by a substance called Keratin in human hair is the structure that maintains the strength of hair. After hair dyeing, disulfide bond will be broken, which will lead to a lot of hair loss.
contact dermatitis: there are many chemical components in hair dyes, which can cause strong irritation to people’s scalp. Especially for sensitive skin, after hair dyeing, the scalp will be itchy and scratched. Red spot, rash and so on are skin allergic reactions, and even anaphylactic shock may occur in severe cases.
heavy metal poisoning: in order to compete in price and save costs, hairdressers will use some cheap and lasting hair dyes. These hair dyes may contain a large number of heavy metal elements. Once these substances enter the body, they may lead to heavy metal poisoning and damage the functions of liver, kidney and other organs.
a black and shiny hair really makes people look younger. For middle-aged people after 50, hair dyeing is the most possible way to achieve “rejuvenation”. How much harm does hair dyeing bring to our health? Can we dye our hair well?
if you want to reduce the risk of hair dye carcinogenesis, you’d better choose plant hair dye when you buy a product. Don’t use some irregular hair dye for cheap. Pay attention to the product name, manufacturer’s name and address, safety warning and use guide, storage conditions meeting the shelf life and safety requirements.
it’s better to do skin allergy test before hair dyeing, especially for people who have experienced allergy in hair dyeing, it is necessary to conduct allergy test before use. Before hair coloring, wear gloves and shawls. Meanwhile, apply latex to the hair and ears to prevent hair coloring from damaging the skin.
the oil secreted by the scalp has a protective effect on the scalp. When dyeing hair, it is necessary to use the scalp oil to resist these harmful substances. Therefore, it is better not to wash the hair with shampoo before hair dyeing.
generally, the cycle of hair dyeing is once a year for long hair and twice a year for short hair. It is better not to dye hair more than twice a year, and each time you just need to dye the newly grown hair.
the second is the pregnant mother who is preparing for pregnancy or is already pregnant. Hair dye contains special substances, not only affect the health of the mother, but also affect the development of the fetus, and even make the fetus abortion and even deformity. For the sake of children, it’s better to give up “beauty”. After pregnancy, do not let the wife do these five kinds of housework, the husband should be responsible for it, otherwise it is easy to hurt the fetus!