Insulin-like growth factor-1 (IGF-1) plays a key role in supporting growth, tissue repair, and metabolism. But new research is shedding light on a more complex reality: both too much and too little IGF-1 may increase your risk of chronic diseases and early death.
A large study from the EPIC-Heidelberg cohort followed over 7,000 people for nearly 18 years. Researchers found a U-shaped relationship between IGF-1 levels and mortality—meaning people with very low or very high IGF-1 were more likely to die from cancer, cardiovascular disease, or any cause. Interestingly, the risks linked to low IGF-1 were even stronger in individuals with liver disease, as the liver is the main producer of IGF-1.
These findings are echoed by data from the UK Biobank, where elevated IGF-1 was linked to a higher risk of several cancers, including thyroid, breast, prostate, and colorectal. However, for some cancers like lung and kidney, the association was weaker or nonexistent, suggesting not all tumors are equally sensitive to IGF-1.
A 2019 meta-analysis of 30,000+ participants confirmed the pattern: IGF-1 levels in the middle range (120–160 ng/mL) were associated with the lowest risk of death. Both very low and very high levels increased mortality.
What can you do? Diet and lifestyle seem to play a role. High intake of dairy, animal protein, and carbohydrates can raise IGF-1 levels. Managing these through balanced nutrition might help keep IGF-1 in the “just right” range.
The bottom line: IGF-1 isn’t all good or all bad. Like many things in health, balance is key. And understanding your IGF-1 levels—especially if you have liver issues or a family history of cancer—might offer useful insight into your long-term health risks.