Published on June 2, 2004 at 8:17 PM
There is no getting around the fact that sunlight is hard on your skin. But what about the positive benefits of sun exposure? The June Harvard Health Letter discusses the good and the bad of the sun. The sun's short UVB wavelengths that cause sunburn can damage DNA and suppress the skin's immune system.
The longer, more penetrating UVA wavelengths may create highly reactive oxygen molecules capable of damaging skin cell membranes and the DNA inside. According to the Harvard Health Letter, skin cancer risk is affected by both a person's genes and skin type. Additionally, the "dose" and the timing of sun exposure are crucial elements to the likelihood of developing skin cancer.
Suddenly getting lots of sun is more dangerous than steady exposure over time. Although sun exposure usually gets a bad rap, the UVB wavelengths also do some good for your skin. These wavelengths kick off the chemical and metabolic chain reaction that produces vitamin D, which may promote bone health. Some people also receive another benefit from letting some sun hit their skin: it helps reverse seasonal affective disorder (SAD), which is usually caused by lack of sunlight.
The Harvard Health Letter says that the key to sun exposure is finding a middle ground between being a "solar-phobic" person and a sun worshiper.
It's important to protect your skin with sunscreen that has an SPF of at least 15 and to wear a hat and shirt around midday if you are outside for an extended period of time. Harvard Health Letter is available from Harvard Health Publications, the publishing division of the Harvard Medical School.
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