It pays to sleep in

Hey, all you ‘early birds’ out in the morning sun, running your laps and digging in the garden!

Yeah, you! It’s bad for your health and you are putting your life at risk. You’d be better off sleeping in and doing those things in the afternoon. At least, when its a sunny morning…

Control of skin cancer by the circadian rhythm

Shobhan Gaddameedhia,b,
Christopher P. Selbya,
William K. Kaufmannb,c,d,
Robert C. Smarte, and
Aziz Sancara,b,d,1

+ Author Affiliations

Departments of aBiochemistry and Biophysics,
cPathology and Laboratory Medicine,
bLineberger Comprehensive Cancer Center, and
dCenter for Environmental Health and Susceptibility, University of North Carolina School of Medicine, Chapel Hill, NC 27599; and
eCell Signaling and Cancer Group, Department of Environmental and Molecular Toxicology, North Carolina State University, Raleigh, NC 27695

Contributed by Aziz Sancar, September 16, 2011 (sent for review August 24, 2011)


Skin cancer is the most common form of cancer in the United States. The main cause of this cancer is DNA damage induced by the UV component of sunlight. In humans and mice, UV damage is removed by the nucleotide excision repair system. Here, we report that a rate-limiting subunit of excision repair, the xeroderma pigmentosum group A (XPA) protein, and the excision repair rate exhibit daily rhythmicity in mouse skin, with a minimum in the morning and a maximum in the afternoon/evening. In parallel with the rhythmicity of repair rate, we find that mice exposed to UV radiation (UVR) at 4:00 AM display a decreased latency and about a fivefold increased multiplicity of skin cancer (invasive squamous cell carcinoma) than mice exposed to UVR at 4:00 PM. We conclude that time of day of exposure to UVR is a contributing factor to its carcinogenicity in mice, and possibly in humans.

Full text here:

I always knew it was a good idea to sleep in and those folks up making all the noise in the morning were indulging in silly and risky business ;-)

Subscribe to feed


About E.M.Smith

A technical managerial sort interested in things from Stonehenge to computer science. My present "hot buttons' are the mythology of Climate Change and ancient metrology; but things change...
This entry was posted in Human Interest, Science Bits and tagged , , , . Bookmark the permalink.

7 Responses to It pays to sleep in

  1. Scarlet Pumpernickel says:

    Awesome. And I think staying out of the sun too much also causes cancer. As vitamin D drops your immunity does too = more cancer…

  2. adrianvance says:

    The vitamin D issue is quite real as it seems to be very involved with immunity, especially in older people. Perhaps the solution is to stay inside and smoke Marijuana as that is supposed to be a natural cancer fighter. That what they are saying now in California now that “pot” is regarded as medicine.

    See The Two Minute Conservative at has political analysis, science and humor. Now in the top 2% on Kindle.

  3. adolfogiurfa says:

    ….and now you are enjoying a brand new “Ozone Hole” up there in the northern hemisphere.

  4. P.G. Sharrow says:

    All of those years my parents and others forcing me to go to bed early to get up early were damaging my health when I knew better! After 65 years I can’t seem to stay in bed even when I may. Darn!
    I have been dealing with squamous cell carcinoma for 40 years, Consumption of peppers seem to help dry up and shrink the carcinomas.
    maybe I should try Canibis cookies. :-0 pg

  5. Pascvaks says:

    I know this doesn’t make sense, but think about it –
    there are morning people and there are the rest of us. I’m not a morning person but I’m married to one. I hate getting up in the morning, always have, takes forever to focus and hear anything. The Mrs. on the other hand is just the opposite, she’s wide awake in the early morning. Now here’s the point, or more properly, the Question: Is is best for Morning People to have AM UV since they’re obviously geneticaly conditioned for it and NOT PM UV? And, on the other side of the issue, is it best for Non-AM people to have PM UV and NOT AM UV? Wonder if there are AM Rats and Non-AM Rats, just like us? Now that would be worth a few billion in Federal Research money, imagine, AM Rats and Non-AM Rats, just like people. Hummmmmm….

  6. Scarlet Pumpernickel says:
  7. larrygeiger says:

    Yes! Truly I am one with nature. Here it is 9:39 in the morning and I am just coming back around to life. I have some outdoor plans for this afternoon that I think will fit very nicely into my recommended UV regime :-)

Comments are closed.