Sunshine is a treasure, but you will see old age when you bask in the sun

Sunshine is a treasure, sunbathing is good for your health. But you "see you old in the sun"?

The growth of everything depends on the sun, and people cannot do without the sun. At one time, sunbathing became a popular way of leisure. But after experiencing some painful consequences, the harmful side of sunlight to the skin has gradually been realized by everyone. So, what is the relationship between sunlight and human skin?

The essence of sunlight is electromagnetic waves, and the composition is very complex. Sun rays are divided into X-rays, X-rays, ultraviolet rays, visible rays, infrared rays, Y rays, and secondary cosmic rays. Among them, the rays that reach the surface of the earth are ultraviolet rays A, B, visible rays and infrared rays, but ultraviolet rays are the most harmful and harmful to the human body, which is referred to as UV for short. Ultraviolet rays are divided into three types: "UVA", "UVB" and "UVC", each of which causes different damage to the body and skin.

Different types of electromagnetic waves, even different bands of the same electromagnetic wave, have different effects on the skin. This creates a relationship between sunlight and skin that is "enemy and friend". For example, the ultraviolet rays that are most related to the skin, although they are all ultraviolet rays, have different bands and have different effects on the skin. Certain bands can cause skin diseases, such as skin sunburn, tanning, aging, photosensitivity, carcinogenesis, etc. Other bands not only cause no disease, but can cure the disease.

As the saying goes, "He's honey, your arsenic".

Specifically, the ultraviolet rays in the sun can kill bacteria in the air, and many molds cannot survive in the sun; ultraviolet rays can also kill bacteria on the skin, increasing the elasticity, softness of the skin and the ability to resist foreign bacteria; sun exposure On the skin, it can stimulate the body's hematopoietic function, promote calcium and phosphorus metabolism and the synthesis of vitamin D in the body, making your bones and body stronger; infrared rays in the sun can penetrate the skin to the subcutaneous tissues, and have a thermal stimulation effect on the human body , To speed up blood circulation, promote metabolism in the body, and have anti-inflammatory and analgesic effects. On days lacking sunlight, the brain will produce a kind of worry hormone, which can make people sleepy and depressed. Sunlight is the best stimulant, which can regulate people’s mood, invigorate the spirit, relieve depression symptoms, improve the taste of life and work efficiency, and can improve Various physiological functions of the human body.

But excessive sun exposure can also cause great harm to health. Photodermatitis can occur when ultraviolet rays are strongly applied to the skin, and erythema, itching, blisters, edema, eye pain, tearing, etc. can occur on the skin. In severe cases, it can also cause skin cancer; when it acts on the central nervous system, it can cause headaches, dizziness, and body temperature. Elevation, etc.; acting on the eyes, it can cause conjunctivitis, keratitis, called photoophthalmia, and may also induce cataracts. Long-term ultraviolet radiation is most likely to cause various spots on the skin. Although ultraviolet rays are present throughout the year, the winter sunlight is relatively mild and the north is foggy, but the ultraviolet rays are only about 20% weaker than summer, and still cause great harm to human skin and eyes. Therefore, it is still necessary to avoid ultraviolet rays in winter. Irradiate. In recent years, a large number of chemicals have destroyed the ozone layer in the atmosphere, destroying this natural barrier that protects human health. According to a report provided by the National Meteorological Center, China's total atmospheric ozone layer has decreased year by year since 1979, and the ozone layer has decreased by 14% in 20 years. And for every 1% decrease in the ozone layer, the incidence of skin cancer will rise by 3%.

1. The harm of sunlight

1.1 The culprit of tanning

In the summer, girls are most worried about tanning! And the "culprit" of tanning is none other than ultraviolet rays. When ultraviolet rays are irradiated on the skin, the skin will quickly enter a self-protection state. By activating tyrosinase, a substance called melanin is produced, which is used to resist the damage of ultraviolet rays to skin cells, but at the same time it will also deepen the skin tone and make Many beauty-lovers who believe in "one white covering a hundred ugliness" have "changed their colors after hearing this." In addition, some common spots, such as freckles and chloasma, can also cause recurrence or aggravation due to sun exposure.

1.2 Getting old accomplices

In addition to tanning, solar radiation also plays an "assist" role in getting older. Ultraviolet rays destroy the skin's moisturizing ability and damage collagen fibers. With long-term development, the skin will age, loosen, rough, and wrinkles will increase. Therefore, the skin starts the process of "photoaging" from the moment it is exposed to the sun. In other words, it begins to experience "photoaging" in infancy.

1.3 Pro-inflammatory master

Sunlight can also cause skin allergies, leading to skin erythema, edema, etc., often accompanied by strong itching, such as polymorphic light eruption, chronic actinic dermatitis, etc. There are many reasons that can induce sunlight to cause disease, including some photosensitivity drugs (hypoglycemic drugs, tetracycline, etc.) and foods (grey cabbage, Chinese cabbage, spinach, etc.), as well as personal mental state, regional environment, seasons, and other factors. Date and time are related.

1.4 Carcinogenic weapon

Ultraviolet rays can also cause cell cancer to become cancerous by damaging the DNA of cells. The most serious skin tumor, melanoma, is related to sunlight. According to research, the accumulated sunshine intensity of a person's lifetime is directly related to the occurrence probability of melanoma. For every 10% increase in the intensity of sunshine every year, the probability of melanoma in men increases by 19%, and the probability of melanoma in women increases by 16%. For non-melanoma skin cancer, it has also been confirmed that the cumulative amount of ultraviolet radiation is an important factor in its pathogenesis. But not all wavelengths of ultraviolet light can cause cancer. It has been found that ultraviolet rays with a wavelength of 300nm~400nm will only cause skin tanning, and the real carcinogenic waveband is between 200nm~300nm.

2. The advantages of sunlight

2.1 Source of Strength

Sunlight gives us physical strength. Ultraviolet rays will promote the production of vitamin D3, and vitamin D3 will strengthen the immune system and act as a catalyst in many metabolic reactions in the body. It can also prevent many diseases, including osteoporosis, colds and various inflammations. Therefore, Professor Hollico of Boston University said: "Vitamin D3, produced by the body through ultraviolet light, is the greatest gift the sun gives to mankind."

2.2 Happy Engine

Sunlight directly affects the brain through our eyes, helps us produce and maintain circadian rhythms, and participates in regulating the secretion of various hormones in the human body by stimulating the pineal gland. When the sun shines for only 1 second, the pineal gland can immediately stop the production of hormones that make people sleepy and depressed, and the brain becomes awake. At 10 seconds of sunshine, adrenaline begins to secrete, which makes people energetic. After 1 minute of sunshine, sex hormones begin to secrete, giving people a good feeling. After 2 minutes of sunshine, the heart beats faster, breathing speeds up, blood pressure rises, metabolism strengthens, and all organs of the body begin to function better. After 3 minutes of sunshine, our body is full of vitality and happiness hormones, our feelings become rich, and we are full of interest when we work. You will want to embrace the whole world.

2.3 Good medicine

Although sunlight can cause many skin diseases, in long-term practice, people have found that sunlight can also be used to treat skin diseases. In the past 40 years, phototherapy, that is, irradiation with a certain wavelength of artificial ultraviolet light (narrow-band ultraviolet light), has been one of the important methods for the treatment of skin diseases. Narrow-band mid-wave ultraviolet can inhibit DNA synthesis, so it can treat the "initiator" of psoriasis-hyperproliferation of epidermal cells. Induces the production of tumor suppressor genes and prevents light carcinogenesis. Because of its immunosuppressive function, it is also widely used in the treatment of inflammatory skin diseases, allergic skin diseases, and skin lymphoma. In addition, sunlight can also regulate blood pressure and help the heart work better; reduce cholesterol and blood lipids, prevent atherosclerosis; it is also a good pain reliever, which is used to relieve pain caused by various diseases.

2.4 Beautiful Magic

The warm sunshine will make us beautiful. As sunlight stimulates the production of vitamin D and the absorption of calcium, the hair roots become stronger, and our hair becomes thicker and more shiny. Sunlight also exerts a positive effect on the pineal gland through the optic nerve. Therefore, our eyes will get a wonderful luster and at the same time our vision will be enhanced. Under the sunlight, the metabolism will also be promoted, the blood supply of the stomach will become better, and the calorie consumption will increase, helping us to maintain a slim and fit body. The blood supply to the skin will also become better due to sunlight, and it will look healthier and ruddy.

3. What about "enemy and friend"?

Since many skin problems are related to sunlight, the importance of sun protection for healthy and beautiful skin is self-evident. The damage of ultraviolet rays to the skin is cumulative. In other words, every time you receive unprotected sunlight, you take a step closer to aging. Therefore, sun protection must be as early as possible, and children should start sun protection. Sunscreen has no seasonality, so it must be "prevented from time to time".

At present, the most effective sun protection methods are mainly physical shielding, such as parasols, hats, long-sleeved clothes, etc., and applying full-spectrum sunscreen. Sunscreen should pay attention to choosing the appropriate sun protection factor and applying thickness and time. If you are outdoors for a long time, you should reapply sunscreen every 2 hours to 3 hours. In addition to the face, sun protection on the neck, hands, eyes and lips is also very important, which is prone to photoaging.

4. Be exquisite in the sun

Sunlight is so important to health, we need to bask in the sun to replenish energy, strengthen our physique, and heal ourselves. So how can we effectively bask in the sun so that we can absorb "nutrition" from it without being hurt by it? Mainly pay attention to two points: timing and time. Scientific research shows that sunlight has different effects on the human body at different times of the day.

6 am to 9 pm: Sunlight contains a lot of infrared rays that make people feel warm, which is good for the skin. It is a good time to exercise outdoors.

9 am to 12 pm: This is the best time to sunbathe. The beneficial ultraviolet A will quickly tan the skin instead of black.

12:00 ~ 16:00: Do not bask in the sun. During this time, the content of ultraviolet B, which is harmful to the skin, is the highest. At this time, the damage of sunlight far outweighs its benefits.

16:00~19:00: The proportion of ultraviolet A that tans the skin is higher. At this time, going to the sun will increase the vitamin D in the body.

Exposure to the sun should be moderate, 30 to 60 minutes a day in the sun is an elixir for the body and mind. But letting ultraviolet light irradiate directly for 3 hours will turn the positive effect of sunlight to the opposite side.

Correctly understand the advantages and disadvantages of sunlight, seek advantages and avoid disadvantages, and promote health.