Insulin-like Growth Factor (IGF-1) has become a mainstay for performance enhancement, and is being peddled at an ever increasing rate. Is it the fountain of youth? Will IGF-1 help build muscle? Is there any proof?
IGF-1 is mainly secreted by the liver, stimulated by Human Growth Hormone (HGH). It is surmised that the anti-aging, muscle building, and lipolysis effects attributed to HGH are actually due to the IGF-1 it stimulates.
Just about every cell in the body is affected by IGF-1, and the benefits attributed include:
• Stimulates hyperplasia
• Causes muscle growth (due to hyperplasia)
• Regenerate nerve tissue
• Reduce protein breakdown
• Burn fat
• Improve leukocyte (white blood cell) production
• Decreases LDL
• Improves absorption of Chondroitin Sulfate and Glucosamine Sulfate.
• Slows the aging process by promoting cells to move from the “resting” phase, to “growth” and “repair” phase
Judging by the above benefits, IGF-1 seems to be the hormone everyone should be taking. But studies on IGF-1 are limited, and the vast majority performed with human subjects are with children suffering from a deficiency. With most of the studies being done on mice and other animals, some disregard them saying they’re not transferrable to humans. While I have to say I agree in many cases that some of the conclusions gathered using animals are not transferable, some studies are very impressive.
An editorial published in Circulation Research discusses the problem of skeletal muscle wasting with chronic heart failure. The author sites the research and explains the important role IGF-1 has in enhancing muscle growth, preventing age-related muscle atrophy, and potentiating regeneration after injury. This is a fairly technical article but is worth reading to understand some of the benefits of IFG-1