Sunlight - free nutrients for life.

   As early as the 1960s, Dr. Albert Szent-Gyorgyi, who won the Nobel Prize in Medicine for discovering vitamin C, once said: "All the energy in our body comes from sunlight."

Sunlight has a balanced and complete wavelength and energy of red, orange, yellow, green, cyan, blue, and purple. It can penetrate the skin and enter the human body, interact and react with various chemicals and minerals, assist in the synthesis of various essential nutrients in the body, and decompose and excrete various types of waste.

Therefore, in addition to affecting plant growth and photosynthesis, sunlight also plays a key role in human health. . All nutrients, minerals and vitamins we take have their own unique energy absorption spectra.

Life without natural sunlight

The sun has existed since the birth of the earth. Early humans lacked adequate clothing to protect themselves, so their bodies were in the closest contact with the sun, and the operation of life was closely coordinated with the rise and fall of the sun. From the endocrine system to the biological clock, all are inseparable from the energy and signals given by sunlight.

Sunlight converts carbon dioxide in the air into plant nutrients through photosynthesis in chloroplasts, which in turn nourishes all kinds of life on earth. From this point of view, the energy that supports the growth of all things and drives our thinking, action and planning ultimately comes from the sun.

Today, I Our clothes cover most of our skin, and sometimes we use parasols or full sun protection equipment to block the sun. In addition, most people work indoors during the day, so the time for sun exposure is extremely limited.

At night, the lights are on everywhere, and we often hold our mobile phones. This mode of receiving light stimulation is exactly the opposite of the needs of the body's biological clock. Insufficient rest at night and lack of energy during the day are a burden on metabolism, immunity, and the mind's cognition and emotions.

Different spectra of sunlight and artificial light

In modern society, we spend more and more time in front of the screen and less and less time outdoors. Indoor artificial lighting has almost replaced natural light. The human body not only abandons the health benefits of full-spectrum natural light, but also loses the health benefits of full-spectrum natural light.

The benefits of watching movies on the Internet are also due to the fact that we often spend too much time in front of the screen, which puts great pressure on our eyes. Moreover, the indoor lighting sources generally used can usually only provide three spectra of orange, green and cyan.

If we are under unbalanced indoor light sources for a long time, it will not only be unhelpful to our physical health, but also make people feel difficult to concentrate, tired, stressed and even anxious.

The spectrum of sunlight is complete, while artificial light such as light bulbs, fluorescent lamps, halogen lamps, and LED lamps can only present a part of the spectrum, and the proportion is also different from that of natural light. Long-term lack of exposure to sufficient natural light is an important factor affecting the health of modern people.

What effects does sunlight have on our health?

1. Synthesis of vitamin D

Vitamin D is known as the "sunshine vitamin" because it is an important nutrient synthesized by the human body after directly absorbing ultraviolet B (UVB) light through the skin. Vitamin D is essential for bone health.

It can promote the absorption and utilization of calcium and help build a strong bone system. Lack of vitamin D can lead to a series of bone problems such as osteoporosis and rickets. In addition, vitamin D is also involved in multiple physiological processes such as immune regulation, cardiovascular health, and blood sugar control.

Its importance is self-evident. However, with the change of modern lifestyle, people's opportunities to bask in the sun have been greatly reduced, and vitamin D deficiency has become a global health problem.

2. Regulate biological clock and mood

The blue light component in sunlight has a powerful regulating effect on human biological clock. It can help us calibrate the circadian rhythm in the body and maintain a normal sleep-wake cycle.

Long-term lack of natural light, especially during the day, will interfere with this natural mechanism, leading to insomnia, day and night reversal, seasonal affective disorder (SAD) and other problems.

SAD patients often experience symptoms such as depression and decreased vitality when there is insufficient sunlight in winter, and increasing sunlight time can effectively alleviate symptoms. In addition, sunlight can promote the release of neurotransmitters such as serotonin in the brain, improve mood, and reduce depression and anxiety.

3. Enhance immune function

Adequate sunlight exposure can enhance the body's immune function. Studies have shown that vitamin D can not only promote the generation and function of immune cells, but also regulate immune responses and reduce inflammation.

During the flu season, people with higher vitamin D levels have a relatively lower risk of contracting the virus. In addition, the ultraviolet rays in the sun also have a certain bactericidal effect.

Although this effect is limited when directly irradiating the skin, it can effectively kill bacteria and viruses attached to them through indirect methods, such as drying clothes and bedding, and reduce the risk of infection.

4. Promote cardiovascular health

There is also a close relationship between sunlight and cardiovascular health. Vitamin D deficiency is associated with an increased risk of cardiovascular diseases such as high blood pressure, heart disease, and stroke.

Vitamin D can regulate blood pressure, reduce the risk of arteriosclerosis, and protect the cardiovascular system through anti-inflammatory effects. At the same time, sunlight exposure can also promote the production of nitric oxide, a gas molecule that can dilate blood vessels and improve blood circulation, which is essential for maintaining cardiovascular health.

5. Improve skin health

Although excessive exposure to the sun can cause sunburn, aging, and even increase the risk of skin cancer, moderate sunlight exposure is beneficial to the skin. Moderate ultraviolet A (UVA) can promote the synthesis of melanin in the skin, which is a natural skin protection barrier that can prevent ultraviolet damage.

At the same time, sunlight can also promote blood circulation in the skin, increase skin elasticity, and improve uneven skin color. The key is to find a balance in sun exposure and avoid direct exposure to strong sunlight at noon.

How to sunbathe correctly

1. Determine the time to sunbathe based on the length of the shadow. Different latitudes, altitudes, seasons and other factors make the time to sunbathe different. You can try to choose the time to sunbathe based on the length of the shadow.

When the shadow is twice or more than the height, the UV index is relatively safe; when the shadow is 1 to 2 times the height, it is safest to control the sunbathing time to about 20 minutes; when the shadow is shorter than the height, ultraviolet rays may cause damage to the skin within 30 minutes.

2. Most people sunbathe for 20 to 30 minutes at a time. Children can sunbathe for a shorter time, and the elderly can sunbathe for a slightly longer time, but it is generally recommended to control it within 30 minutes to prevent sunburn.

For people living at high altitudes and in long-term hypoxic environments, because hypoxia itself will aggravate bone loss, they need to extend the sun exposure time to 30 to 60 minutes a day.

3. Outdoors is the best place for sunbathing. Studies have shown that the transmittance of the required band of ultraviolet rays through window glass is less than 50%. If it is 4 meters away from the window, it is only 2% of that outdoors. Therefore, if you have to choose to sunbathe indoors, you should open the window to let your skin directly contact the sun.

4.  You can wear shorts and short sleeves in summer and expose your hands in winter. Generally speaking, the skin on the trunk is more sensitive to sun exposure than the limbs, and the skin on the upper limbs is more sensitive than the lower limbs.

The skin on the face is relatively thin and needs to be protected. The skin thickness of the back of the hand, extremities (arms, legs) and other places is moderate, which is a good place to receive ultraviolet rays.

5. You should also pay attention to your diet. Some foods or medicines can increase or decrease the skin's sensitivity to light.

Sunlight can be said to be a "free nutrient" given by God to humans. When you have time, you must go out often and bask in the sun together~