Chronic Jet-Lag Conditions Hasten Death in Aged Mice
Researchers at the University of Virginia have found that aged mice undergoing weekly light-cycle shifts - similar to those that humans experience with jet lag or rotating shift work - experienced significantly higher death rates than did old mice kept on a normal daylight schedule over the same eight-week period. The findings may not come as a great surprise to exhausted globetrotting business travellers, but the research nonetheless provides, in rather stark terms, new insight into how the disruption of circadian rhythms can impact well-being and physiology, and how those impacts might change with age.
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As someone who worked 6/2 shiftwork for years, I can say that it does get harder as you get older. I worked it last 20 years ago, and I don't know that I could do it now, though at the time it didn't bother me much - and the bother was because it cut into my ability to go to movies, plays, and ballgames more than anything else (our shifts started at 6am, 2pm and 10pm, so eve or mid shifts sliced right through the real world's evenings). However a lot of my coworkers hated the rotating shifts ... even when we went to just day/eve with a permanent mid shift of volunteers.
What about people with phase disorders? I've been wondering how all this circadian rhythm disruption research applies to people with delayed/advanced sleep phase syndrome.
Larks find it very difficult. Owls find it easier. There are some people whose clocks are just more flexible than others, easily moved around (not strong larks or owls) and they tend to enjoy night shifts. Rotating shifts are hard on anyone in the long run, though, especially if they are going the "wrong way", i.e., advancing every week instead of delaying every week.
I'm sorry I guess I wasn't clear. I didn't mean I wanted to know with what relative ease someone with a phase disorder could adjust to non-standard shifts. I was wondering about the whole hastening-death-will-give-you-cancer reports that have been coming out about shift work.
Oh, there has been quite a lot of data on night-shift workers (nurses) and their highly increased incidences of breast cancer, peptic ulcer, etc. You may also want to read this.
Those reports never say if the nurses are naturally night people.
What I'm wondering is if being an owl (which I am), and working a night shift that coincides with your body clock, is better or worse than forcing yourself into daytime shift.
The articles always say working night shifts is bad but they never say if it's bad because the people working them are day people or if it matters what their clocks are naturally set to.
Those studies usually cover nurses who worked night-shifts for 20 years or longer. People who remain on this schedule for so long are largely self-selected, people who can stand it, or even like it, yet, they still suffer negative health consequences.
I don't buy it. I've been a natural night owl since I was seven years old. I've been working the afternoon/evening and night shifts ever since I graduated from high school. I tried a few different times throughout the years to adjust to a "normal" schedule -- each time for several months in a row. The first time I tried it -- at 23 years old, I slept from 11:00pm till 7:00 am and worked from 8:30 am till 5:00 pm (a typical daytime schedule). As the months passed, I started to feel pain in my knees that just wouldn't subside. At first, I thought I must be getting some kind of chronic illness. Then it happened that I found a new job on the afternoon/evening shift. Lo and behold -- my very first day of sleeping till noontime, the knee pain was gone and didn't return until several years later when, for the second time, I tried to adjust to a so-called "normal" schedule. After several months of feeling like I had arthritis in my knees, I decided to go back onto an evening shift again. Sure enough -- the excruciating knee pain disappeared again from the very first day of sleeping later. The third and most recent time I tried to adjust to a morning start time was four-and-a-half years ago. It was even worse than the first two tries. Not only did the pain in my knees return, but as the months passed, I felt increasingly more run-down until I started to become physically depressed. Again, the very first day I slept later, the knee pain vanished and I felt nineteen years old again.
Apparently, later work hours have been very good for my health. I say this because I'm a forty-six year old female who has always effortlessly maintained a perfect body mass index, I've never had an illness, and have never needed medication of any kind. I know if I had stayed on the day shift, I would definitely have ruined my health.
I truly believe that some day health researchers will be advising the public that the best way for people to maintain good health is for each of us to work and sleep on our own individual ideal schedules whenever possible.
Well, if you read my blog regularly, you know that I emphasize how much variation there is in the human population - some are larks, some are owls, some are rigid, some are flexible - thus I often argue that every individual person has to find his/her own best schedule and the employees will need to adjust to it.