Are you still dyeing your hair? I'm afraid you don't know these dangers yet

Perming can make women more beautiful and make elderly people with white hair look younger, but frequent hair dyeing will make the hair dry, broken, and dull. There is also a saying that hair dyes contain various chemical ingredients that can induce cancer. What harm does hair dye bring to us? How can we dye our hair to minimize its harm? Today, let’s listen to the advice of Wu Liangcai, Director of the Department of Dermatology at the Sixth Affiliated Hospital of Sun Yat-sen University!

What problems may occur after using hair dye?

Hair damage and loss.

The hair dyeing process will affect the moisture imbalance in the hair, and the denaturation and reduction of a large amount of protein, etc., which will cause the hair to become brittle, the fibers to break, and lose its natural softness, toughness and gloss.

Repeated use of hair dye can damage the protective layer of hair fibers. Over time, hair will become thinner and more fragile, making it more susceptible to damage in the future. The acute and chronic stimulation of hair dye can cause inflammatory reactions in the scalp and hair follicles, which over time can cause atrophy of the hair follicles, causing the hair to become thinner and eventually fall out. Therefore, people who frequently use hair dyes are likely to have dull and lifeless hair, or even cause pathological hair loss.

Allergic reaction.

After dyeing your hair, you must closely observe whether you experience milder symptoms such as scalp redness, itching, and scaling, as well as more serious allergic reaction symptoms such as scalp and facial edema and blisters, which can occur from a few hours to a few days. If scratched, it can easily lead to bacterial infection.

In rare cases, the whole body may be affected, possibly because the hair dye flows into the whole body with the water when washing the hair or taking a bath. If the condition is serious or lasts for more than two days, you should go to the dermatology department of the hospital to see a doctor in time. Also, do not use different brands of hair dye at the same time. Hair dyes may react chemically to produce toxic substances and increase the chance of allergies.

May cause cancer.

The correlation between hair dyes and cancer has indeed been confirmed in some literature, especially the correlation with blood tumors. Clear carcinogens have also been found in some commercially available hair dyes, such as 4-aminobiphenyl. But overall, the research results have not yet reached a clear conclusion and lack confirmation from large-scale studies.

Heavy metal poisoning.

Various hair dyes contain dozens of chemical ingredients. According to tests conducted by relevant departments on more than 100 types of hair dyes, nearly 90% of them contain toxic chemicals such as nitrobenzene and aniline. According to the "Cosmetic Hygiene Standards" (2007 edition), hair dyes allow a certain amount of mercury, lead and arsenic, and inferior hair dyes contain higher lead content.

Some imported hair dyes also contain lead acetate, which contains 5-10 times the amount of lead in household paints and pigments. Long-term and repeated hair dyeing can cause chronic lead poisoning, resulting in a series of lead poisoning symptoms such as dizziness, headache, fatigue, numbness of the limbs, cramps in the calf, abdominal pain, etc. Lead can also enter the liver, kidneys and brain, destroying the functions of these organs. In severe cases, lead can cause loss of labor.

Medical experts point out that if hair dye is used for a long time, as long as 1% is absorbed into the human body through the skin, it will accumulate and cause poisoning. The chemical substances will combine with certain cells, damaging the deoxyribonucleic acid in the cell nucleus, causing cell mutations and inducing skin cancer, bladder cancer, leukemia, etc. Therefore, experts warn to be vigilant about "diseases entering the body through hair."

Why are middle-aged and elderly people more likely to suffer toxic reactions after hair dyeing?

Many elderly people are very keen on dyeing their hair in order to turn their gray hair black. However, studies in many countries have shown that people who frequently dye their hair have an increased incidence of breast cancer, skin cancer, leukemia, and bladder cancer. Especially for middle-aged and elderly people, due to their low resistance and decreased immunity, they are more likely to suffer from toxic reactions after hair dyeing, contact dermatitis, and even tumors than young people.

Young people who dye their hair have a relatively lower probability of getting sick. This is because highlights are often used when dyeing hair, which often does not touch the junction of the hair roots and the scalp. Middle-aged and elderly people have more white hair, so they need to dye a large area of ​​their hair, or even their entire head, black, which causes their skin to absorb hair dye year after year. In addition, their physical condition is relatively poor and their metabolism slows down, so they are more susceptible to allergies and cancer.

Patients with diabetes, hypertension, and heart disease should be cautious when dyeing their hair; patients with allergic diseases such as asthma, boils, skin ulcers, blood diseases, and tumors should stay away from hair dyeing.

If the elderly really want to dye their hair, they should try to go to a professional hair salon; do a skin test before dyeing their hair; and choose semi-permanent dyes. Middle-aged and elderly people should not dye their hair too frequently, nor should they change hair dyes frequently, because the chemical ingredients added to each hair dye are not exactly the same. If they are changed frequently and exposed to multiple chemical ingredients, it will also increase the probability of disease and cancer.

If you experience symptoms such as itchy scalp, red and swollen scalp, or rash after dyeing your hair, you should stop using the hair dye; if you experience systemic symptoms such as dizziness and fatigue, it may indicate a systemic toxic reaction and you are advised to go to the hospital for examination in time. In addition, elderly people who frequently dye their hair should also go to the hospital for regular physical examinations.

How can we minimize the harm of hair dyeing?

First, choose the right hair dye.

Wu Liangcai said that hair dyes are divided into three categories: temporary hair dyes, semi-permanent hair dyes and permanent hair dyes, each with its own advantages and disadvantages.

○ Temporary hair dyes are generally applied to the hair surface with water-soluble dyes and are available in liquid, paste and spray forms. Its advantages are that it is non-toxic and has little harm to the body, while its disadvantages are that the color is poor and the effect is short-lived. This type of hair dye has poor color fastness and is easy to rinse off. If you are attending a temporary event such as a performance, this type of hair dye is suitable.

○ Semi-permanent hair dyes are mostly in the form of shampoos, and the main dyes include nitrophenylenediamine, nitroaminophenol, azo acid dyes, etc. When using, apply shampoo to your hair and rub it, leave it on for 20-30 minutes, then rinse it off and you can color it. The advantage is that it is more resistant to washing than temporary hair dye, but the disadvantage is that it has a certain degree of toxicity.

○Permanent hair dyes are mainly divided into two types: plant-based and oxidative

Plant type: using substances extracted from plant flower stems and leaves as raw materials, dyeing is completed through physical, chemical and other methods. The advantage is that it is safe and non-toxic. The disadvantage is that it is more expensive.

Oxidative type: Available in the form of cream, liquid, shampoo, etc. Their main raw materials include two preparations. The first dose is a dye and the second dose is a developer. Mix the two parts on the hair. The dye is responsible for opening the hair cuticle to allow the color developer to enter the hair. In addition, the dye intermediate reacts with the oxygen decomposed by hydrogen peroxide to produce active oxygen that decomposes melanin and causes hair discoloration. The advantage is that the color is fast and not easy to wash off, but the disadvantage is that it is somewhat toxic.

Second, learn the skills of hair dyeing

Mastering certain hair dyeing techniques can also reduce the harm of hair dye to the body.

Tip 1: Avoid touching your scalp. Before dyeing your hair, apply lotion (such as Vaseline) on the hairline, try to avoid contact with the scalp, neck, and facial skin. It is best not to dye the 1 cm area around the hair roots to isolate it from contact with the hair dye. Although inconsistent hair color does not look good, it does little harm to your health.

Tip 2: Do a skin test three days in advance. Hair dye can be more harmful to you if you are allergic to it. How do I know if I am allergic to a certain hair dye? You can test it before dyeing your hair by applying a small amount of hair dye behind your ear and observing for 3 days to see if your skin develops redness or itching. If so, the product cannot be used.

In addition, we would like to remind everyone to wash their hair several times after dyeing it, so as not to leave any residue in the hair; when washing your hair, be careful not to scratch your scalp to avoid poisoning.

Finally, I would like to emphasize that people with scalp wounds, chronic diseases, women who are about to become pregnant or are already pregnant, and people with allergies should not use hair dye. If you can avoid using hair dye, then do so!