Top 10 Bad Things That Are Good For You | LiveScience

Sunlight

Exposure to the sun's rays is necessary to survive, but can also kill you in gross, cancerous quantities. Asthmatics, at least, could benefit from measured doses of ultraviolet rays, according to scientists. Sunlight suppressed the immune reactions that cause asthma in some lab studies with mice and could be used to treat humans afflicted with the disease in the future. And sunlight--even if indirect, such as on a shaded porch--is known to boost the mood. Extra sunlight can help office workers avoid afternoon drowsiness, a recent study found. There's still no excuse to head outside and bake, however.

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