Finally: a nightshift study that considers natural rhythms

I just read this study: Night Shift Might Boost Women's Breast Cancer Risk. As usual it says I'm going to die young of chronic diseases because of shift work. But I am intrigued because it's the first such study I've seen that considers the participants' natural biorhythms. The people who said they were "morning people" were sick MORE than the others. It's one study, but I've always pondered whether this factor would change the data. When I work days, I have trouble sleeping at night, and I'm sick constantly, feel terrible, get zits, and gain weight. I would rather work nights, die young, and feel good in the meantime, I guess. I'm glad to see that researchers are addressing whether natural night owls are subject to the same ills as sun-lovers forced to work nights.