Hair dyeing, as the "standard of renewal" in the New Year, is one of the Spring Festival rituals that many Chinese people insist on.
Literature shows that more than 2,000 years ago, the Western Han Dynasty politician Wang Mang dyed his hair and beard black in order to cover up his old age.
In 1863, the British chemist Perkin created the first synthetic dye, which is also the basis of modern hair dyes.
According to the "2020 China Beautiful Consumption Trend Report", the average Chinese people colored their hair 2.9 times in 2019. Behind the frequent change of hair color, there may be hidden health risks.
"Life Times" (search for "LT0385" in WeChat to pay attention to) interviews experts to reveal the harm that frequent hair coloring may bring to the human body, and teach you a few tricks to minimize the risk of hair coloring.
Experts interviewed
Yang Shuxia, chief physician of the Department of Dermatology and Venereology, Peking University First Hospital
Professor of Dermatology, Shenzhen Hospital, Southern Medical University, Liang Yanhua
You Yan, member of the Medical Aesthetics and Beauty Branch of the Chinese Medical Association
Hair dyes are mainly divided into 3 categories
At present, there are many types and brands of hair dyes on the market, and the slogans such as pure natural, pure plants, good coloring, and non-fading are also very eye-catching, so that consumers can pick their eyes.
To choose a healthy, safe, effective hair dye that suits your individual needs, you must first understand their respective characteristics.
Hair dyes are mainly divided into the following categories:
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Temporary hair dye
It only needs to be washed once with shampoo to remove, its particles are large, can not enter the hair root through the epidermis, but are deposited on the surface of the hair, forming a coloring overlay, so it is relatively safe.
Semi-permanent hair dye
The principle of this type of hair dye is to "hang" the color on the surface of the hair, generally resistant to 6 to 12 washes, after applying to the hair, stay for 20 to 30 minutes after the color can be colored.
Since hydrogen peroxide is not required, it does not damage hair, and it has become more popular in recent years.
Permanent hair dye
It is mainly composed of the following categories:
It should be reminded that some hair dyes claim to use traditional Chinese medicine or plant ingredients, which can be used daily like ordinary shampoos. In fact, these products may also contain hair dye ingredients, which does not equal pure natural.
Frequent hair coloring poses a health risk
With the gradual occupation of the market by household hair coloring products, many people prefer this cost-effective way of self-coloring. While bringing convenience, it will also cause some harm to the human body.
1
Skin allergies
P-phenylenediamine, as the main component of hair dyes, can make the color of the hair after dyeing firmer, but it is also a strong allergen, which can easily lead to skin allergies, of which contact dermatitis is the most common.
2
Aggravates hair loss
One of the causes of hair loss is frequent hair coloring.
Because some hair dyes contain benzene compounds, they can penetrate into the small fur, an important part of the hair, and the oxidation reaction occurs, which in turn leads to dryness, breakage and even hair loss.
3
Liver and kidney damage
Although the quality and safety of hair coloring products have improved in recent years, some products will add heavy metals such as lead, mercury, arsenic and other heavy metals to enhance the dyeing effect, and some have a lead content of 5 to 10 times that of paint.
Frequent use will cause chronic damage to the body, not only may lead poisoning symptoms such as dizziness, numbness of limbs, abdominal pain, etc., but also damage the function of organs such as liver and kidneys.
4
There is a possibility of carcinogenicity
In 2020, a 36-year-old joint study involving more than 120,000 participants, completed by Harvard University and other institutions in the United States, confirmed that the use of permanent hair dyes was associated with an increased risk of skin cancer, breast cancer, ovarian cancer, and lymphoma.
Users of permanent hair dyes had a slightly increased risk of developing cutaneous basal cell carcinoma compared with no users.
The frequency and dosage of hair dye are positively correlated with the incidence of breast and ovarian cancer, and for every 50 times the number of hair coloring increases, the risk of breast cancer increases by 1% to 2%.
Women with natural dark hair who had used permanent hair dyes had a 289% increased risk of developing Hodgkin lymphoma.
Poor hair coloring habits exacerbate the risk
The following erroneous hair coloring habits are more likely to aggravate the harm of hair coloring than frequency:
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Hair color on smog days
According to the international authoritative scientific journal "Materials", hair dyes contain harmful substances such as secondary amines. As a dye fixative, it can make the color more stable, but it penetrates into the hair and skin and stays for weeks, months or even years.
It reacts with tobacco smoke or exhaust gases in the air to form a strong carcinogenic chemical nitrosamine.
The color is too dark and too bright
In general, darker or brighter hair dyes have a higher content of p-phenylenediamine. Hair dyes containing compounds such as p-phenylenediamine are more harmful to hair and scalp.
Dyeing and scalding synchronization
The potions used in perms contain alkaline ingredients and oxidants, which will destroy the hair layer and lose protection of the internal structure of the hair, resulting in yellow, brittle hair, no elasticity and shine.
At this time, the coloring of the hair is undoubtedly worse for the damaged hair.
The European Cosmetics Association recommends that the interval between two hair colorings should usually be more than 4 to 6 weeks, and domestic hair care experts recommend not more than 4 times a year.
Remind 5 types of people that it is best not to dye their hair, the risk of disease is greater:
People who are allergic to hair dyes: any one of the ingredients of the hair dye may induce allergies;
Scalp damage: such as people with eczema, boils, ulcers and other skin breakage or skin diseases, the toxic and harmful substances of hair dye are more easily absorbed into the body;
People who are old and weak, liver and kidney dysfunction: such people have weak resistance, and the elderly have more gray hair, need a large area, or even the whole head is black, more likely to occur toxic reactions;
Pregnant and nursing women: pregnant women are sensitive and more prone to allergies when dyeing their hair;
People with a family history of cancer: they are more likely to develop tumors than the average person and should dye their hair as little as possible.
4 tricks to minimize the risk of hair coloring
In view of the peak period of hair coloring near the end of the year, Life Times combined with the reminder of the Shanghai Municipal Consumer Protection Commission, teaches you a few ways to minimize the risk of hair coloring.
Purchase regular, qualified products
Do not try to be cheap when buying hair coloring products, and be sure to choose regular and safe products. It is best to have an industry approval number, such as the mainland hair dye has the logo of "special name of wei makeup", in order to prove its safety.
Do a test-sensitization experiment before dyeing your hair
Before hair coloring, an allergy test is done: apply a small amount of hair dye to the back of the ear, the inside of the arm, etc. After 72 hours, no allergic reactions should be used.
People with more sensitive skin, it is best to go to the hospital for patch experiments and observe for 72 hours.
Avoid contact with skin
When coloring your hair, avoid direct contact with the skin. If you accidentally come into contact with hair dye on your head or face, apply it immediately with Vaseline or wipe it clean in time.
For people with more sensitive head skin, a thin layer of refreshing lotion can be applied along the hairline before hair coloring.
Use professional wash and care products after dyeing
After hair coloring, it is necessary to wash the excess hair dye in time, do not remain on the skin, it is best to choose a special shampoo and conditioner after dyeing. ▲
Editor of this issue: Zhang Yu
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