IGF-1 and Life Expectancy in the Elderly

Insulin-like growth factor 1, IGF-1, is one of a number of items of great interest for the mainstream of gerontology, those researchers focused on the workings and manipulation of metabolism. It also remains an area of uncertainty at this time, with apparently contradictory results abounding:

it has become apparent that single gene mutations in the insulin and insulin-like growth-factor signalling pathways can lengthen lifespan in worms, flies and mice, implying evolutionary conservation of mechanisms. Importantly, this research has also shown that these mutations can keep the animals healthy and disease-free for longer and can alleviate specific ageing-related pathologies. These findings are striking in view of the negative effects that disruption of these signalling pathways can also produce. ... The underscored passage brings up an issue that we've discussed here previously: Why is it that IGF-I pathway mutations can confer long healthy lives on organisms, even though supplementation with IGF-I is often quite beneficial, and depletion of IGF-I is often bad for individual organ systems? Indeed, according to another recent study, low doses of IGF-I appear to protect the mitochondria in aging rodents - why then do completely IGF-I-deficient animals enjoy extended and healthy lives?

Adding more IGF-1 in an unmodified metabolism seems to be good, but modifying metabolism to completely remove it seems to be much better. To add to these results in animals, an improved testing methodology for humans shows that more IGF-1 activity is apparently better in the elderly:

Elderly men with higher activity of the hormone IGF-1 - or insulin-growth factor 1 - appear to have greater life expectancy and reduced cardiovascular risk


In this study, researchers evaluated 376 healthy elderly men between the ages of 73 and 94 years. A serum sample was taken from each subject at the beginning of the study and researchers were contacted about the status of the participants over a period of eight years.

Subjects with the lowest IGF-1 function had a significantly higher mortality rate than subjects with the highest IGF-1 bioactivity. These results were especially significant in individuals who have a high risk to die from cardiovascular complications.

These new findings come as a result of a new form of testing for IGF-bioactivity. Researchers in this study used a new method, a bioassay, to measure the function of IGF-1 in the blood. Compared to commonly used methods to measure IGF-1, the IGF-1 bioassay gives more information about the actual function (bioactivity) of circulating IGF-1 in the body.

What this doesn't tell us is whether IGF-1 activity is a cart or a horse in this correlation - cause, consequence, or a little of both? I suspect that levels of IGF-1 activity are greatly influenced by obesity, metabolic syndrome, diabetes, general aerobic fitness, risk of atherosclerosis, levels of oxidative stress, and other line items of biochemical damage and poor choice that correlate with a lowered life expectancy.

So eating yourself into an early grave and hoping to dig your way out with hormone supplementation is not the way to go, as always. Neither life nor your metabolism works that way.


I dont know what to think, in the UK a documentary was shown on the BBC stating that fasting for a few days reduces IGF-1 and causes cells to repair themselves rather than multiply which intern dramatically reduces risks of cancers and CV problems resulting in extended longevity. I am a natural bodybuilder and consume over 300g of protein a day , now to increase IGF-1 in the body protein is the key so not so good for me, if you have a low carb and very low protein diet then the documentary stated you will live to an old age. hopefully some facts will come out soon as this affects everyone. and i know i am not ready for the grave yet

Posted by: Phillip at August 13th, 2012 8:25 AM

I saw that programme too, and afterwards watched some programmes about bodybuilders thinking these guys are really messing themselves up. I don't think you need 300 grams of protein a day unless you weigh 300 pounds. But it's not the protein itself that makes you stronger it's the amino acids in the protein which can also be obtained from non protein sources like fruit and veg

Posted by: marc at September 10th, 2012 7:06 PM

All amino acids (also in fruits and vegs) comes in the form of: PROTEIN.

It is the amino acids in fruits and vegs that raises your IGF-1.

Posted by: AntonO at March 3rd, 2013 3:30 PM

telomeres and telomerase

Hello, i am not an expert in anything, but i think that i know why something as beneficial as IGF-1 accelerate your death,( different to your elderliness, phenomenon that not happen whit igf-1, because is going to make you feeling young and so on, right?)-(whit new and fresh cells)

so how something that makes you younger and healthy, can accelerate the time of your death (ho beautiful moment of ascension and freedom!!!) ok, so how something as hgh that use hollywood starts for look younger, can accelerate the death? something that makes you stretch whit more energy sexual potency and continues the list of attributes of an young animal, and don't forget growth!!!
the typical characteristic in young specimens. it look like a joke right.

ok, so i believe i have the answer to this contradiction, the answer is this:

TELOMERES: every time that a cell get divided the telomere in his chromosomes got shorted, when is to short the cell doesn't get divided any more. when your cells can get divided any more you died.

igf-1 promote cell duplication.

here it comes recipe for immortality: there is a enzyme call telomerase the enlarges telomeres, is it said that tumor cells produce that enzyme and is for that that they can get divided infinitely in contrast whit normal cells that in vitro get divided 21 times or something.



Posted by: Alberto at November 19th, 2013 9:07 PM

"Why is it that IGF-I pathway mutations can confer long healthy lives on organisms, even though supplementation with IGF-I is often quite beneficial, and depletion of IGF-I is often bad for individual organ systems?"

The mutations affect the IGF-1 receptor, so if you have a mutated receptor the IGF-1 uptake is impaired leading to a high IGF-1 concentration in plasma.

SO HIGH IGF-1 CONCENTRATIONS ARE BENEFICIAL. you will cycle the repairing mechanism of you body faster, and you will be better.

The bad thing: If you use IGF-1 in order to body-build you will have a boost for sure, but being strong like a bull pays a big toll: your metabolism will also boost, and the body will live less due to this increase: just think about the body as a motor... it has mileage limit, if you speed the metabolism you will arrive to that limit sooner ( is for that reason that people on low carb diet will live far more).

But those two things are different matter. use IGF-1 to extend your life not to boost your metabolism far beyond a healthy body.

Posted by: victor at March 12th, 2015 6:27 PM

Actually, what is going on as a discussion here. can anyone firmly tell that IGF-1 is bad or good. Kindly if anyone who has used this material can come forward and share their experience. Only genuine user.

Posted by: Salim at June 26th, 2015 11:19 AM

I am about to administer IGF1 to my Maine Coon. He is fifteen years old. He has slowed down and has lost lots of muscle. Lower energy and some mood detrrioration. It is on the recommendation of a vet. I believe it will improve his mood and energy. Restore muscle tone. Improve his liver and kidney function. And extend not inly his life but the quality of his life.

Posted by: Wendy at December 18th, 2015 3:31 AM
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