What causes age spots and can you prevent them?
Years of sun exposure is the clearest cause of age spots. Consistent sun protection is the smartest prevention; for existing spots, a pigment-targeting laser works best.
Age spots are caused by years of sun exposure. They typically appear from your thirties onward on areas that catch a lot of sun: the hands, forearms and face. The more sun hours you have accumulated, the greater the risk.
In your skin, a disrupted distribution of pigment plays the central role. Brown pigment (melanin) is produced by specialised skin cells. As you age, fewer of those cells remain, but the ones that do work overtime and distribute the pigment unevenly. At the same time, pigment accumulates in the deepest skin layers because cells are renewed more slowly. The pigment system itself is not switched on extra; it is more a matter of disrupted cell turnover.1,2,3
A chronic low-grade inflammation also plays a part. UV radiation and cellular ageing together raise an inflammatory receptor in skin cells, which prompts pigment cells to form extra projections and deposit more melanin. Cell culture experiments have also shown that a protein that normally keeps cells in balance is less present in age spots, causing more pigment-stimulating substances to be released. This has not yet been confirmed in studies in humans.4,5
Prevention starts with sun protection. Because sun exposure is the direct cause, using sunscreen consistently is the most logical step. Large prevention trials are lacking, but the logic is solid. For existing spots, short-pulse lasers that target pigment specifically are the best-supported treatment. They produce clear improvement with few side effects, although those results rest on case reports and literature reviews, not on large randomised studies.6,7
Supplements and plant-based extracts are not yet ready to be recommended. In one small study, a daily dose of 100 mg of blood orange extract (15 days) substantially reduced the increase in melanin following UV exposure, but that is a single preliminary finding. An extract from a rose species stimulated a protective protein in cell culture experiments, but that is purely laboratory research.8
Based on 9 claims from studies with PMIDs 27621222, 16859612, 2186781, 37522429, 41303453, 27693716, 28911859, 24910279. The role of UV and melanin production is mechanistically well supported. The finer cellular processes have been demonstrated in cell and laboratory research. Laser treatment is supported by case reports and literature reviews. Blood orange extract rests on one small study in humans. Large randomised studies are lacking for both prevention and most treatments.