The sun’s harmful effects on the skin: antioxidants are your greatest weapon

We always hear how the sun has numerous benefits and is essential for life on Earth. However, the position of the sun changes from one season to another, and the sun’s radiation is more intense in the summer, so its harmful effects on your skin are also increased. This is because the Earth is closer to the sun and the rays strike the northern hemisphere more perpendicularly, so in the summer there are more hours of daylight and greater exposure to the sun.

Your skin is the organ that is most exposed to the environment and therefore to its effects, which include the effects of the sun.

Fortunately, short-wavelength solar radiation, UVC rays, which are regarded as the most dangerous, do not pass through the atmosphere and are absorbed by the ozone layer, so they have no effect on your health.

UVB radiation is mostly absorbed by the ozone layer, but some of it reaches the earth’s surface. This allows your body to synthesise vitamin D, which is essential for proper metabolic function, not only in your bones but also in your immune system, and it also helps to prevent diabetes, cardiovascular diseases and cancers. This radiation is less able to penetrate the skin, but it causes sunburn and indirect pigmentation of the skin by activating melanosomes to produce additional melanin, your skin’s natural protector.

UVA rays are not absorbed by the atmosphere and have a greater capacity to penetrate the skin and reach the dermis. UVA radiation is responsible for immediate tanning. It is capable of oxidising the existing melanin as a natural protective measure, so sunspots are more visible after a small amount of exposure to the sun. It also causes the skin to thicken, leading to dryness and wrinkles.

UVB and UVA radiation cause oxidative stress in the body, both directly and indirectly. Sunburn is triggered by reactive oxygen species, which stimulate the inflammation process. Proteins, lipids and even DNA are also oxidised. Changes in skin pigmentation are promoted by reactive oxygen species that can destroy melanocytes and trigger vitiligo, but melanogenesis is also activated and skin pigmentation is increased. UV radiation causes immunosuppression of the skin, leading to skin infections and the formation of tumours. The sebaceous glands are also stimulated and acne may occur in some cases. Collagen and extracellular matrix degradation mechanisms are also activated as a side effect of the radiation, resulting in what is known as photoageing of the skin.

We must not forget that we also get infrared (IR) and visible radiation. Most of the IR radiation that reaches us is infrared A (IR-A). This radiation is capable of penetrating to the hypodermis, causing stress in the skin. It increases the effects of free radicals, causing collagen loss which leads to deep wrinkles in the skin, and it also strengthens the oxidative effects of UV rays.

Visible light, or what we call blue light, can cause skin damage due to oxidative stress, so one of its effects is to activate melanocytes to increase skin melanin, resulting in signs of skin ageing that are similar to those caused by UVA radiation. This radiation comes not only from the sun but also from the devices we use regularly, screens, fluorescent lights and any LED that emits white light.

Antioxidants:  your greatest weapon to combat the sun’s negative effects on your skin in the summer

Most of the sun’s effects on the skin are caused by oxidative stress, so it is best to prevent these effects through an antioxidant-rich diet and supplements.

To counteract the harmful effects of the sun on your skin, the summer provides us with fruits and vegetables that can help us to eliminate free radicals from the body. Oral supplementation with powerful antioxidants has been shown to promote immunoprotection, decrease skin erythema, and therefore help to slow down photoageing.

Antioxidants that you can get through your diet or by taking natural supplements:

• Punicalagins: which are found in pomegranates, will reduce the effects of radiation on your skin, preventing photoageing.
• Hydroxytyrosol: is found in olive oil and olive extract.
• Ferulic acid: contained in vegetables, pulses, cereals, fruits and the seeds of plants such as rice, pineapple, oats and wheat.
• Glutathione: found in spinach, watermelons, grapefruit, asparagus, avocados, strawberries, pumpkins, broccoli, cauliflower, walnuts, garlic and tomatoes.
• Vitamins C and E: contained in berries, citrus fruits, broccoli, avocados, olive oil, tomatoes, etc.
• Superoxide dismutase: found in barley, broccoli, Brussels sprouts, cabbage and wheat.
• Coenzyme Q10: contained in meat, fish, fruits, vegetables, etc.

Remember to combine sunscreen with supplements or an antioxidant-rich diet to protect your skin from photoageing.

Bibliography:

Marianne Gosch C et al. The role of oxidative stress in skin ageing. Rev. Chilena Dermatolo. 2010; 26(4): 351-357

Nora Alejandra Zuluaga Espinosa et al. Vitamin D: new paradigms. Medicina & Laboratorio 2011, Vol 17, N 5-6.

Yuya Nakashima et al. Blue light-induced oxidative stress in live skin. Free Radic Biol Med. 2017 jul; 108:300-310

Claire Regazzetii et al. Melanocytes sense blue light and regulate pigmentation through opsin-3. J Invest Dermatol. 2018 Jan;138(1):171-178