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From a medical or skin care perspective, “sun damage” usually refers to the effects of sun exposure on the skin’s appearance over a lifetime.
Sunlight is paradoxically necessary and useful for the skin at times. It helps in the formation of vitamin D, (1) which is required to keep your bones strong and healthy.
UV energy in small incremental doses also stimulates the production of melanin, (2) which helps protect the skin from excessive and harmful future doses of sunlight. However, excessive sunlight UV energy can cause permanent skin damage.
Mechanism of Sun Damage
Every time that skin is excessively exposed to solar energy, it undergoes some permanent change. The effect of damage is mostly on the proteins that manage the production, repair, and metabolism of cells.
Cumulative sun damage over a lifetime results in the development of free radicals. These free radicals give off damaging energy to other healthy structural molecules such as collagen, elastin, DNA, and chromosomes.
- Collagen is a structural protein that gives skin both strength and thickness. (3) New collagen formed from damaged templates will not be strong enough to prevent stretching, resulting in skin laxity.
- Elastin is another protein that allows the skin to resume its original dimension after being stretched/pulled out. (4)
Damaged elastin results in skin that has effectively “lost” its ability to return to its unstretched form.
Symptoms of Sun Damage
The many signs of sun damage include those that are visible to the eye as well as some effects of actual damage to the internal skin structure that can only be seen through a microscope.
Externally, the skin gradually shows the appearance of aging. It is estimated that 80% of the damage to skin that causes an aging appearance is from unavoidable UV exposure! (5)
The multiple signs of damage include:
- Skin laxity (stretching out of the skin), especially in the uncovered areas such as the face and neck
- Irregular melanin pigmentation
- Localized darker pigmented areas called sunspots
- Precancerous rough, flaky surfaces
What Is Hyperpigmentation?
However, hyperpigmentation can also result from other causes, including:
- Hormonal imbalances from diseases such as Addison’s disease
- Melasma, (7) which often occurs during pregnancy and when taking birth control pills or receiving hormone replacement therapy
- Skin injuries such as abrasion, burns, and reactions to chemical peels and laser treatments
Reversing Sun Damage
Sun-damaged skin cannot be “reversed” in terms of the chemical damage to each molecule and cell. However, with the progress in medical science, synthetic peptides and actual growth factors from a culture medium/broth of healthy skin are now available.
These can be incorporated into medical-grade topical skin care products to promote new growth of skin cell types and collagen and, in effect, “rebuild” damaged skin.
While moderate amounts of sunlight are beneficial to your health, excessive exposure to the harmful UV rays can cause skin damage. This damage generally presents itself in the form of skin aging. However, at the cellular level, it can cause permanent change and can even lead to cancer.
Therefore, it is best to avoid harsh sun by using protective clothing and applying sunscreen. You can also consult your dermatologist for existing sun damage or future prevention.