User Tag List

Informational! Informational!:  0
Likes Likes:  0
Page 1 of 2 12 LastLast
Results 1 to 8 of 11

Thread: Smoking and obesity are linked to age-related chro

  1. #1

    Join Date
    Nov 2004
    Location
    Jacksonville, Florida
    Posts
    2,154
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    It isn't news that eating fatty foods and smoking can shorten your life expectancy through heart attacks and cancer. But now a study shows that a lifetime of these unhealthy habits can directly 'age' DNA by years.

    Strings of DNA are often capped by highly repetitive sequences known as telomeres. Like the plastic tips on the ends of shoelaces, telomeres help to protect genes against wear and tear. But each time a cell divides, the proteins involved in replicating our DNA fail to copy the telomeres completely. So these sections get shorter as the years pass.

    Tim Spector, director of the twin research unit at St Thomas' Hospital in London, and his team have shown that telomeres shrink dramatically in patients who are obese or heavy smokers. "Shorter telomeres mean you will run out of steam sooner than people with longer ones," adds Edward Louis of the University of Nottingham, UK.

    Obese women in the study were, according to their telomeres, nine years 'older' than slim women of the same age, explains Spector. Heavy smokers, who consumed a pack a day for 40 years, showed seven years of extra biological ageing.

    People do distinguish between growing older and dying earlier.

    Tim Spector
    Director of the Twin Research Unit at St Thomas' Hospital, London



    Researchers already knew that smoking and obesity could cause a kind of stress in cells that produces reactive chemicals, which in turn are known to wear away telomeres. Spector's large study looks directly at this effect to quantify just how much a cigarette can age you.

    Clocking up years

    Spector's team collected information and blood samples from more than 1,100 women aged between 18 and 76 years. Within this group, 11% had a body mass index greater than 30, which classified them as clinically obese. About 18% were active smokers.

    The researchers sequenced the DNA of the women's white blood cells to find the length of their telomeres. Overall, they found that a woman's telomeres shorten by about 27 base pairs a year; a base pair being a single letter of DNA in your genetic sequence.

    But heavy smokers wore an additional 200 base pairs off their telomeres after 40 years of puffing. And obese participants' telomeres were, on average, 240 base pairs shorter than those of their lean counterparts.

    ADVERTISEMENT


    According to the authors of the report, which appears in The Lancet1, this ageing effect might help to explain why these women are at a greater risk of age-related health problems such as heart disease. But, Spector adds, it is important to note that the whole body ages faster under this kind of stress, not just the heart.

    Spector says the immediate impact of such ageing could provide a different motivation to quit smoking or start a diet, alongside the fear of one day contracting cancer or heart disease. "People do distinguish between growing older and dying earlier," he says.

    The research team now plans to examine the effects that exercise, diet and occupation have on telomere length.

  2. #2
    Stay chooned in for more! Clint's Avatar
    Join Date
    Apr 2003
    Location
    Metro Atlanta Area
    Posts
    9,681
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    man, i need to stop smoking!

  3. #3

    Join Date
    Jul 2005
    Location
    WITNESS PROTECTION
    Posts
    26
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I can tell you that I haven't had fast food or a sip of soda since November...a big reason for this was the documentary "Super-Size Me"...I never ate much fast food to begin with and i know "everything in moderation" but that grossed me out so much that I just can't eat it anymore.

    It's definately worth seeing, in fact it should be shown in every health class in the country.
    \"You may know who we are but we know who you are.\"

  4. #4
    StifflerMichael's Avatar
    Join Date
    Aug 2004
    Location
    Dallas, TX
    Posts
    339
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    In humans, telemores shorten (we lack the enzyme telomerase which repairs the shortening) regardless of whether you smoke or are obese, many scientist think it accounts for aging. I studied this a little bit in a course I took at the Harvard Med school last year--the data is pretty inconclusive as to whether or not telomere shortening is involved in aging.

  5. #5

    Join Date
    Mar 2005
    Location
    Evanston, IL
    Posts
    836
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    all I know is a ciggy and a tall frosty coke get me up and going every morning...and I don't look like I'm near 50, either. I look.......38, LOL!

    It's a good article, though. I read it. Nature is one of the magazines I get where I work.
    \"People place their hand on the Bible and swear to uphold the Constitution; they don't put their hand on the Constitution and swear to uphold the Bible,\" Jamie Raskin, to Senator Nancy Jacobs.

  6. #6
    Let's positive thinking! seedjar's Avatar
    Join Date
    Dec 2004
    Location
    Olympia, Washington
    Posts
    4,064
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by [b
    Quote[/b] (StifflerMichael @ July 06 2005,6:23)]In humans, telemores shorten (we lack the enzyme telomerase which repairs the shortening) regardless of whether you smoke or are obese, many scientist think it accounts for aging. I studied this a little bit in a course I took at the Harvard Med school last year--the data is pretty inconclusive as to whether or not telomere shortening is involved in aging.
    But isn't it true that loss of telomeres is a cause of cancer and genetic disorders? Telomeres wear off on all DNA at vary speeds; it's the end of a polymer chain, so naturally it's subject to decay. Once transcription errors start cutting into the ends of coding sections of DNA, there's going to be trouble, no matter how you look at it. I think it's important to distinguish that while telomere shortening may not cause the physical manifestations of aging, it is a significant cause of disease.
    And Clint, yes, please do quit! You're still young enough that it might be easy. I was a heavy smoker at the beginning of high school and feel very lucky that I was able to quit after two and a half years. A lot of kids I know and knew from back then are pretty much hooked for good, after as little as a year. One of my friends acts like such a jerk without cigarettes that I've given up on letting him quit - he's just too intolerable and I know he's never going to stick it out anyways, so I give him packs when he starts to talk about quitting (somebody else will if I don't.) Don't let yourself get to the point where you're unbearable.
    ~Joe
    o//~ Livin' like a bug ain't easy / My old clothes don't seem to fit me /
    I got little tiny bug feet / I don't really know what bugs eat /
    Don't want no one steppin' on me / Now I'm sympathizin' with fleas /
    Livin' like a bug ain't easy / Livin' like a bug ain't easy... o//~

  7. #7
    War. War never changes. Est's Avatar
    Join Date
    Apr 2004
    Location
    Champaign, IL
    Posts
    3,935
    Mentioned
    3 Post(s)
    Tagged
    1 Thread(s)
    While the research implacations are interesting, this should in no way be life-shattering for anyone. Smoking is bad for you, being very overweight is bad for you. We already knew that, didn't we? Dunno, I'm all for people quitting smoking and eating a healthy diet, but I'm somewhat surprised by some of the reactions I've seen simply because we know smoking is very bad for you, we know what it can do and someone telling you that you'll be losing basepairs faster than other people doesn't seem to be the "usual suspect" in terms of people changing their ways. Dunno, I just find it mildly perplexing. Oh well, if it helps as an incentive to quit, then the more power to you.

    Transcription errors during the synthesis of new DNA templates are pretty durn uncommon (only one in several million or something in that ballpark IIRC) and even then the chances that the error will occur in a coding area is extremely slim. Still, since pase pair changes can be catastrophic, it can shift an entire sequence (codons are sections of 3 basepairs(bp) and if just one bp gets left out, it shifts what the entire following sequence codes for, or it can signal a "stop" so the rest of the sequence is not even "read.") While telomeres do increase the numbers of bps in a DNA strand, their purpuse isn't to prevent transcription errors (IIRC) but rather to protect coding DNA from oxidation. Eat your fruits and veggies to make sure you get antioxidants that (are beleived to) aid in the prevention of oxidation. I beleive that smokes have lower telomere bp counts because smoking kills some cells so other cells have to go through mitosis (means more transduction, translation, and transcription!) and that means more wear on the telomeres! Hence, the areas where the smoke goes (eg lungs, or mouth) are sites to higher rates of cancer and other problems.

    So, all in all, fun to read and it made me remember telomeres, though it doesn't change anything (ie, smoking and obesity were always known to be unhealthy) it's still an interesting prospect.
    \(_o)/ ಠ_ಠ
    My Growlist
    NASC Website Come join in on the fun!

  8. #8
    StifflerMichael's Avatar
    Join Date
    Aug 2004
    Location
    Dallas, TX
    Posts
    339
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I don't think there is any association between telomere shortening and disease either--seems logical that there might be, but there is none discovered to date.

Page 1 of 2 12 LastLast

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •