Graveyard shift work linked to cancer

Discussion in 'Et Cetera, Et Cetera' started by Principessa, Nov 30, 2007.

  1. Principessa

    Gold Member

    Joined:
    Nov 22, 2006
    Messages:
    19,494
    Likes Received:
    28
    Gender:
    Female
    Graveyard shift work linked to cancer
    By MARIA CHENG, AP Medical Writer
    Thu Nov 29, 8:25 PM ET

    Like UV rays and diesel exhaust fumes, working the graveyard shift will soon be listed as a "probable" cause of cancer. It is a surprising step validating a concept once considered wacky. And it is based on research that finds higher rates of breast and prostate cancer among women and men whose work day starts after dark.

    Next month, the International Agency for Research on Cancer, the cancer arm of the World Health Organization, will add overnight shift work as a probable carcinogen. The American Cancer Society says it will likely follow. Up to now, the U.S. organization has considered the work-cancer link to be "uncertain, controversial or unproven."

    The higher cancer rates don't prove working overnight can cause cancer. There may be other factors common among graveyard shift workers that raise their risk for cancer.
    However, scientists suspect that overnight work is dangerous because it disrupts the circadian rhythm, the body's biological clock. The hormone melatonin, which can suppress tumor development, is normally produced at night.

    If the graveyard shift theory eventually proves correct, millions of people worldwide could be affected. Experts estimate that nearly 20 percent of the working population in developed countries work night shifts.

    Among the first to spot the night shift-cancer connection was Richard Stevens, a cancer epidemiologist and professor at the University of Connecticut Health Center. In 1987, Stevens published a paper suggesting a link between light at night and breast cancer.

    Back then, he was trying to figure out why breast cancer incidence suddenly shot up starting in the 1930s in industrialized societies, where nighttime work was considered a hallmark of progress. Most scientists were bewildered by his proposal.

    But in recent years, several studies have found that women working at night over many years were indeed more prone to breast cancer. Also, animals that have their light-dark schedules switched develop more cancerous tumors and die earlier.

    Some research also suggests that men working at night may have a higher rate of prostate cancer.

    Because these studies mostly focused on nurses and airline crews, bigger studies in different populations are needed to confirm or disprove the findings.

    There are still plenty of skeptics. And to put the risk in perspective, the "probable carcinogen" tag means that the link between overnight work and cancer is merely plausible.
    Among the long list of agents that are listed as "known" carcinogens are alcoholic beverages and birth control pills. Such lists say nothing about exposure amount or length of time or how likely they are to cause cancer. The American Cancer Society Web site notes that carcinogens do not cause cancer at all times.

    Still, many doubters of the night shift link may be won over by the IARC's analysis to be published in the December issue of the journal Lancet Oncology.

    "The indications are positive," said Vincent Cogliano, who heads up the agency's carcinogen classifications unit. "There was enough of a pattern in people who do shift work to recognize that there's an increase in cancer, but we can't rule out the possibility of other factors."

    Scientists believe having lower melatonin levels can raise the risk of developing cancer. Light shuts down melatonin production, so people working in artificial light at night may have lower melatonin levels.

    Melatonin can be taken as a supplement, but experts don't recommend it long-term, since that could ruin the body's ability to produce it naturally.

    Sleep deprivation may be another factor in cancer risk. People who work at night are not usually able to completely reverse their day and night cycles.

    "Night shift people tend to be day shift people who are trying to stay awake at night," said Mark Rea, director of the Light Research Center at Rensselaer Polytechnic Institute in New York, who is not connected with the IARC analysis.
    Not getting enough sleep makes your immune system vulnerable to attack, and less able to fight off potentially cancerous cells.

    Confusing your body's natural rhythm can also lead to a breakdown of other essential tasks. "Timing is very important," Rea said. Certain processes like cell division and DNA repair happen at regular times.

    Even worse than working an overnight shift is flipping between daytime and overnight work.

    "The problem is re-setting your body's clock," said Aaron Blair, of the United States' National Cancer Institute, who chaired IARC's recent meeting on shift work. "If you worked at night and stayed on it, that would be less disruptive than constantly changing shifts."

    Anyone whose light and dark schedule is often disrupted — including frequent long-haul travelers or insomniacs — could theoretically face the same increased cancer risk, Stevens said.

    He advises workers to sleep in a darkened room once they get off work. "The balance between light and dark is very important for your body. Just get a dark night's sleep."
    Meanwhile, scientists are trying to come up with ways to reduce night workers' cancer risk. And some companies are experimenting with different lighting, seeking a type that doesn't affect melatonin production.

    So far, the color that seems to have the least effect on melatonin is one that few people would enjoy working under: red.
    ___

    American Cancer Society's list of known and probable carcinogens from IARC and National Toxicology Program: ACS :: Known and Probable Carcinogens
    International Agency for Research on Cancer: IARC - INTERNATIONAL AGENCY FOR RESEARCH ON CANCER
     
  2. Northland

    Gold Member

    Joined:
    Oct 22, 2007
    Messages:
    6,082
    Likes Received:
    4
    Most of my working career has been spent working nights. Starting back in the 1970s I worked as a ticket agent at the Port Authority (well now, it was actually for Greyhound Bus), that lasted until the April of 1985. Then I moved up in the world and spent 6 months as a desk clerk for a midtown hotel (part of an international chain). Even when I entered the exciting field of accounting, I managed to find corporations who desired night workers. More recently I have crafted some of my best stories during the quiet night hours- all while drinking coffee and eating sugary foods and burgers. Amazingly, I have decent health. I wonder if it would have worked out differently if I had worked days and been forced to interact with stressed out white collar workers. For me there was less stress from the people around me during the graveyard shifts and that in turn meant less stress to me, which may be what has saved my health. Also to be considered in my situation is that I thrive on the night air and cringe when I see too much sunlight in the forecast- rainy days can be soothing.

    When I go to the all night place at 4 a.m. for a Reuben sandwich and fried onion rings, the atmosphere is much more serene than when I have noontime meetings with my agent at the same place. Clearly I can go out during the sunny daylight hours- as is seen in my avatar image- I just am not as comfortable then, and that to me (stress and uncomfortablility), would be a contributing factor to illness.



    Thank you for posting the information.
     
  3. SpeedoGuy

    Gold Member

    Joined:
    May 18, 2004
    Messages:
    4,229
    Albums:
    1
    Likes Received:
    10
    Gender:
    Male
    Location:
    Pacific Northwest, USA
    As one who worked night shifts as well as rotating shifts, I got out of it just as soon as I could. I'm glad to say I don't have to live that wretched, miserable type of life anymore. It has to be endured to be believed.
     
  4. earllogjam

    Gold Member

    Joined:
    Aug 15, 2006
    Messages:
    5,027
    Likes Received:
    21
    There is something about sunlight that keeps me from going into the dark depths of depression. I need that light. It is essential like water, food, sleep. The short days and long nights of winter bring that feeling of glum into my life every year. I used to live in a god forsaken place weatherwise in upstate New York where the sun barely came out in the winter and I just hated it. It just drains all the color in your life. I had 3 lifetimes of rain living in that place.

    If I slept during the day and worked during the dark I definitely would have psychological and health problems without a doubt.
     
  5. Mr. Snakey

    Gold Member

    Joined:
    Apr 9, 2006
    Messages:
    24,702
    Likes Received:
    25
    I worked many a Graveyard shift and any other shift. Very interesting.
     
  6. B_Think_Kink

    B_Think_Kink New Member

    Joined:
    Oct 25, 2006
    Messages:
    10,742
    Likes Received:
    17
    Gender:
    Female
    I fail to see how working a certain set of hours will determine if you get cancer. It's got to be a marketing ploy.
     
  7. whatireallywant

    Gold Member

    Joined:
    Jun 4, 2007
    Messages:
    3,587
    Likes Received:
    7
    Gender:
    Female
    I've worked all shifts and while I prefer the usual Monday-Friday day shift (except for that getting up in the mornings part!), I actually did prefer graveyard shift over second shift. With second shift I could not have a life outside of work, because all the social things were on weekday evenings while I was at work. When I worked graveyard shift, I went to school part time (in the evenings! :eek:) and slept in the daytime.

    My body seems to like second shift best though - I'm a night owl and always have been. But I like that shift the least of all - the only thing I'd hate worse is that rotating shift where you can't get used to any one shift without going to a different one!
     
Draft saved Draft deleted