SSS 2011-11-07(在线收听

The early bird gets the worm, and may avoid skin cancer. Because a new mouse study suggests that for humans, tanning in the mornings may be less likely to permanently damage in DNA and cause skin cancer. A mouse’s levels of the DNA repair protein XPA are different from ours. They peaked in the morning and bottom out in the evening. Researchers expose mice to UV radiation when their XPA was at their minimum level, around 4 a.m., and other to the same rays around 4 p.m. when XPA levels peaked. Mice who tanned while low on their repair protein develop skin cancer faster and 5 times more frequently than their evening tanning counterparts. The studies in the Proceeding of the National Academy of Sciences. Unlike mice, humans are nocturnal, so their XPA level raise and fall at different times. In people, XPA at prime DNA repairing levels in the morning, which does look like the safest time for UV exposure. So if you want to avoid skin cancer, probably go to the tanning’s long early, or better yet, don’t go at all

 

  原文地址:http://www.tingroom.com/lesson/sasss/2011/11/163928.html