Dr. Rhonda Patrick

Among healthy people,

this association disappeared.

So does a high animal protein diet really pose a health risk, or is it more about what unhealthy lifestyle factors exist in someone's life?

This is where it gets interesting.

Protein, particularly from animal sources, spikes levels of a hormone called IGF-1, which can help build muscle, support brain health,

It enhances muscle repair.

But high IGF-1 levels also come with potential downsides, like promoting the survival of precancerous cells and potentially allowing them to form cancer.

Numerous studies have found an association between elevated IGF-1 levels and an increased risk of various cancers.

So should we cut protein drastically to lower IGF-1 levels?

Not necessarily.

Lowering IGF-1 too much can come with its own set of risks.

For example, calorie restriction, which significantly drops IGF-1, has been linked to brain matter loss and non-human primates.

This raises questions about whether low IGF-1 might have trade-offs in terms of brain health.

So is it better to significantly cut protein intake and avoid these risks, or is there a balance to be struck that gives us the best of both worlds?

Muscle strength, muscle repair,

cognitive health, and protection against cancer.

A recent meta-analysis by Dr. Walter Longo and colleagues highlighted this idea, showing a U-shaped relationship between IGF-1 levels and mortality.

Both very high and very low IGF-1 were linked to higher death rates.

What was the optimal range?

It was actually around 120%