Human growth hormone and IGF-1 have been shown to play a significant role in:
-Conversion of body fat to muscle mass
-Growth of all tissues
-Energy level
-Tissue repair
-Whole body healing
-Cell replacement
-Bone strength
-Brain function
-Sexual function
-Organ health and integrity
-Enzyme production
-Integrity of hair, nails, skin and vital organs
Basically, anything that goes on in your body is in some way tied to HGH. This is why HGH is often called the "fountain of youth". Elevated HGH levels are what makes you feel young again. - (1*, 2*, 3*)
Does your body always produce HGH?
The good news is that your body must always produce HGH or you would not be able to function. The bad news is that as you get past about 20 years old, your body produces less and less HGH each year. By age 60 you will probably have lost 75% of the HGH that your body produced.
If you are a numbers person, here are some average HGH secretion levels:
At 20 years old we average 500 micrograms/day
At 40 years old we average 200 micrograms/day
At 80 years old we average 25 micrograms/day
Why does the body produce less HGH as we get older?
This is the million-dollar question. It really ties into the bigger question - Is aging a preventable disease? For years people have believed that as we get older our body basically wears out. The theory went that all of our organs, tissues, muscles, bones, etc. have a set life span and will get weaker as we age. When someone is 40 and complains that they can't do what they did at 20, we accepted this as the natural process of getting old.
Research into HGH shows that aging may be preventable to a certain extent. Let me clarify that, I am not saying that we will all become immortal (except for Dick Clark - he never seems to age). What I am saying is that research indicates that our body is very capable at the age of 40 to have the same makeup as we did at the age of 20. Okay, I am getting a little carried away - let's get back to HGH...
It was originally believed that the pituitary gland just didn't have the capacity to produce large amounts of HGH as we get older. However, recent studies have shown that aging pituitary glands are capable of producing as much HGH as young pituitary glands, if it is adequately stimulated. This shows that the somatotrophe cell, the cell in the pituitary gland that releases HGH, does not "lose power" as we age.
The questions still remains, if the problem is not with the pituitary gland, then why does HGH decrease as we age? One theory is that the pituitary gland does not "know" it should be producing more HGH. Our body has a feedback loop that says when the IGF-1 levels decrease, produce more HGH. For some unknown reason it is possible that this loop is broken and the pituitary gland has a harder time getting the signal to produce more HGH as we age.
Another theory is that as we get older our Somatostatin levels increase. Somatostatin is a natural inhibitor to growth hormone. So, as we age the somatostatin levels increase and this leads to a decrease in HGH. - (1*, 2*)
