Well a higher protein intake increases the “turnover rate” (it both increases the protein breakdown, and the protein synthesis so there is actually both a building and “destructive” power from eating more protein. Net effect is though, that the building effect is bigger than the destructive effect.)
It’s the same subject as when some talk about how severe kcal restriction might make you age slower …
But I doubt there is any evidence which in a solid way show those results, the way it’s shown here.
Though there is more and more evidence that kind of claim that way to much protein, perhaps have not been as harmless as we used to think … I have to honestly say that the research I have seen on the area have still not changed my evaluations/believes, – so I still stand by the recommendations I have given in here so far.
The old men I know, that is in the best shape, also all eat plenty of protein (perhaps around 180-200 grams a day), – that is what I would use myself, also if I where at an old age…
One thing also is to be weak and skinny, and perhaps have a little slower ageing … especially when I get older, I would personally rather die of cancer a week before I otherwise would, and then be able to actually have just a tiny bit of muscle mass and actually function.
But it’s actually a lot more complicated topic than just the things I have mentioned here.
A more real life explanation is to look at the trends and effect for people eating more protein: does it make them eat less veggies and fruit, does it make them eat more saturated fat, more sauce, fried food and so on …
There is a huge difference between someone who goes on an Atkins diet, or eat more protein rich burgers at Burger King or a hard training man who also increases his energy need. so on, there is many things to consider here.
And a high protein diet where u eat 7 meals each with 30 grams of protein is different than a high protein diet where you eat 2 smaller meals with 25 grams of protein and one larger meal with 160 grams of protein. Turnover rates should not be neglected.
What I understood from the China Study was that high protein intake indeed speeds up aging, the book mentions that around 1900 girls and boys would in the US would reach puberty around 16/17, whereas nowadays the average age is 12/13, quite a big difference!
In my, of course over-simplistic understanding, protein makes things grow inside of you. Anything. If a tumor were to be discovered inside of me I would probably switch to a vegan diet. But for muscle growth and a neat physique you need protein intake.
Protein may be a correlation but there’s so many other factors, so much other trash, antibiotics/hormones in our food. Seems a bit simplistic to me.