Little Stereo skrev:
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> Barnis skrev:
> --------------------------------------------------
> -----
> > Det är många idrottare som har riskerat
> hälsan
> > med doping. Armstrong höll som bekant på att
> dö
> > av cancer, var det en tillfällighet att
> cancern
> > spred sig som en löpeld i kroppen ?
> >
> > GH Enhancers: Are They Worth the Risk?
> >
> > by Hans R. Larsen, MSc ChE
> >
> >
> > Growth hormone (GH) enhancers are getting a
> great
> > deal of attention these days especially among
> > bodybuilders. An 8-week course of GH enhancer
> is
> > reputed to produce 15 or more pounds of solid
> > muscle when combined with regular weight
> > training(1).
> >
> > Human growth hormone is necessary for growth and
> a
> > deficiency produces short people. GH does not
> > actually stimulate growth directly, but causes
> the
> > release of insulin-like growth factors,
> > particularly insulin-like growth factor 1 or
> > IGF-1. It is IGF-1 that is responsible for
> growth
> > and it stimulates the synthesis of lean muscle
> > mass in particular. Human IGF-1 levels vary
> with
> > age; they are particularly high during puberty
> and
> > by the age of 60 years they are only about half
> > the average value (200 micrograms/liter) of a
> > younger adult(2,3).
> >
> > Experiments to increase IGF-1 levels in older
> men
> > through injections of recombinant (synthetic)
> GH
> > produced astounding results. An 8.8% increase
> in
> > lean body mass, a 14.4% decrease in fatty
> tissue,
> > a 1.6% increase in vertebral bone density, and
> a
> > 7.1% increase in skin thickness were reported
> by
> > American medical researchers in 1990. Their
> trial
> > lasted a year and although the 21 participants
> all
> > remained healthy except for one who developed
> > prostate cancer, the researchers warned that
> side
> > effects such as edema, hypertension, diabetes,
> and
> > enlargement of the heart could occur with
> > prolonged use of synthetic GH. Other
> researchers
> > found that GH injections in young people
> produced
> > larger muscles and kidneys. More recently GH
> > injections have become popular among athletes as
> a
> > super- efficient way to increase muscle mass
> and
> > strength(1,4).
> >
> > Growth hormone is naturally secreted by cells
> in
> > the pituitary gland and acts on the liver to
> > produce IGF- 1. IGF-1 levels are normally quite
> > steady, but increase during periods of
> excessive
> > stress, through exercise, and by consuming a
> diet
> > rich in certain amino acids especially
> arginine,
> > ornithine, glycine, and lysine. These amino
> acids
> > act directly on the pituitary gland to
> stimulate
> > the production of GH and its downstream fellow
> > hormone, IGF-1. So why not just eat a lot of
> these
> > amino acids if you want to grow bigger muscles?
> > Unfortunately, or perhaps fortunately as we
> shall
> > see later, stomach acid is very tough on amino
> > acids and only 10% or less of them actually
> > survive long enough to get into the blood
> stream.
> > This is where GH enhancers play a role. These
> > products use a patented process to protect the
> > amino acids in the stomach and as a result 90%
> or
> > more of them are absorbed into the blood
> stream.
> > It is claimed that the resulting flooding of
> the
> > pituitary gland with the raw materials it needs
> to
> > produce growth hormone can result in IGF-1
> level
> > increases of 200% or more. Surprise, surprise!
> The
> > body has a built- in mechanism to prevent IGF-1
> > levels from going too high. Somatostatin is
> > released by the hypothalamus and its major role
> is
> > to keep IGF-1 levels under control. Another
> > challenge for supplement purveyors? Not really
> > since GH enhancers also contain special
> peptides
> > which suppress the natural release of
> > somatostatin(1-3).
> >
> > Now, why would the body go out of its way to
> > prevent high IGF-1 levels when they result in
> > rippling muscles, sculpted bodies, and virtual
> 10
> > to 20 year age reversal in older men? Why
> indeed?
> > The answer is simple, excessive IGF-1 levels
> can
> > make you very, very sick and yes, they can
> > actually kill you! High IGF-1 levels in
> children
> > who are not yet fully grown cause gigantism and
> > excessive levels in adults are associated with
> > acromegaly. Acromegaly is not a fun thing with
> > such manifestations as fatigue, coarse facial
> > features, headaches, decreased vision,
> congestive
> > heart failure, kidney stones, joint pains, and
> of
> > particular interest to young men, impotence and
> a
> > lack of sexual desire. It is said that
> > acromegalics look more like each other than
> like
> > their own family members. As a matter of fact,
> > some pictures of bodybuilders on GH enhancers
> look
> > suspiciously like the classic depictions of
> > acromegalics. Acromegalics also have higher
> > incidence of cancer especially colon cancer and
> > pituitary tumors(2,5).
> >
> > OK you may say, I can live with this as long as
> I
> > have the largest muscles on the block. But can
> you
> > also live with prostate, lung, and colon
> cancer?
> > Researchers at the National Institutes of
> Health
> > reported a connection between cancer risk and
> high
> > IGF-1 levels in 1995. In 1998 researchers at
> the
> > Harvard School of Public Health reported that a
> > high IGF-1 level is the single most important
> risk
> > factor for prostate cancer and that high IGF-1
> > levels were present many years before the
> cancer
> > was actually diagnosed. Other researchers have
> > found that high IGF-1 levels combined with high
> > testosterone levels are a potent risk. High
> IGF-1
> > levels have also been implicated as strong risk
> > factors in breast and colon cancers and now
> lung
> > cancer is about to be officially added to this
> > list. Recent research has shown that
> artificially
> > increasing IGF-1 levels in mice accelerates the
> > growth of cancerous tumors(5-10).
> >
> > Dr. Samuel Epstein, MD, a professor at the
> > University of Illinois School of Public Health
> > says that "Taking supplements to increase your
> > IGF-1 levels is reckless, extreme, and
> bordering
> > on the criminal". Dr. Derek LeRoith of the
> > National Institutes of Health agrees and says
> that
> > there is now enough evidence that taking GH
> > supplements when you are not deficient will
> > increase the risk of cancer and acromegaly.
> Says
> > Dr. LeRoith "If you ask me if I would take
> them,
> > the answer is a definite no". Dr. Michael
> Pollak,
> > a member of the Harvard team who reported the
> > prostate cancer connection also condemns the
> use
> > of GH enhancers by normal, healthy individuals.
> > Dr. Pollak points out that growth hormone
> > supplementation has a definite place in
> medicine
> > in cases where people are deficient and need to
> > increase their IGF-1 levels from sub-normal to
> > normal. However, people who have normal levels
> > would run a significantly increased risk of
> > acromegaly and prostate cancer if they were to
> > take GH enhancers on a sustained basis. Dr.
> Pollak
> > is also concerned about giving IGF-1 to older
> > people with normal levels for their age. He
> says
> > the benefits are uncertain and the risks
> > unknown.(5,11-13).
> >
> > A distinguished group of researchers at the
> > University of Bristol in the UK recently voiced
> > their concern about the increasing use of IGF-1
> > and growth hormone enhancers by bodybuilders
> and
> > elderly people trying to recapture their youth.
> > Says Dr. George Davey Smith "People using
> growth
> > hormone and IGF-1 enhancers are unlikely to be
> > aware of their potentially harmful
> effects".(14)
>
> Det är ingen nyhet, fast canser fick ju just
> arstrong väldigt tidigt i karriären, störst
> risk löper dom som var aktiva i slutet på 70 och
> början av 80 talet och som flertalet har gått
> bort senaste åren i canser (typ Fignon mfl) :-/ T
Bra fråga, ber om ursäkt.
