"Whole and nutrient rich foods"

This is really the key. I'm not a fan of protein powders because consuming a whole protein source whether it be a glass of milk or a ribeye steak is a much more nutrient dense option.

Honestly, a lot of the Blue Zones data we have is very sketchy. For example if you look at Okinawa, they actually consume a moderate to large amount of pork...but they are eating more of the animal.

The only reason some nutrition studies have shown high protein diets negatively influence longevity is because many of them used purified protein sources. The high methionine content is problematic if glycine is too low.

I would also add that muscle is a really important metabolic tissue and protein intake is critical to maintain muscle, especially as we age.