Well, shit.
Turns out caloric restriction doesn’t do a whole lot for humans. Does for mice… but we’re not mice. We’re frontloaded as a species (which is apparently what helped us edge out the Neanderthals in the resource race), but not so severely front-loaded as mice, who won’t survive more than a year in the wild no matter how good shape they’re in, and thus need to live hard and fast if they want to continue to survive.
But they ARE finding that protein may be contributing to IGF-1, which causes a lot of the aging problem. Given that we get most of our protein from red meat, it may also explain the “excess iron” problem most adults have in their mitochondria (which, given the way women tend to lose iron in menopause, may actually explain the lifespan difference).
So now we’re looking at .7 to .8 grams per kilogram of body weight, per day, as a possible (and possibly much more comfortable) longevity path.
I’m 6′, 180. 180/2.2 = ~81kg. 81*.7 = ~56 grams of protein per day.
Pulling this back into units I actually deal with on a daily basis… 56*.0353 = just under two ounces of protein per day. In other words, the porkchop I just had at lunch just did it.
Serious tradeoffs, folks. On 2 ounces of protein per day, you may be perfectly healthy (and vegans they’ve checked out doing this apparently have been). In addition, this dovetails with some startling evidence suggesting that specific kinds of primarily vegetarian diet can be VERY good for you.
On the other hand, you’re not going to be a strength athlete on that little protein per day, and there may be variations due to genetic diversity going on, as well. Bottom line: if you need the muscle, you’d better get the protein, but if you don’t… it’s probably a good idea to munch more veggies and less critters.
What is not explained here is the protein source, and that may count — would a low-iron protein source result in different IGF-1 levels than a high-iron source? Fish for the win?
Happycrow's Eyeball Factory 
Anna
/ September 25, 2008Iinteresting. One cup of yogurt (I just had my mid-afternoon snack) has about 7 grams of protain in it; you might want to recheck those calculations, it seems just a mite too low for me.
Alex
/ September 25, 2008I think the source of protein will turn out to be very important. There are several types of food that may be rich in a particular nutrient, but not all of it is easily accessible by our digestive system.
convivialdingo
/ September 25, 2008Either that… or IGF-1 levels are not in a 1:1 relationship with extending life.
Makes you wonder if there every could have been a biological basis for an actual “fountain of youth.”
Mike
/ September 25, 2008This sounds like junk science to me, or something like global warming. This MUST be a front for veggens and PETA and ALF.
Yes I am kidding, but NO I am not going to change my eating habits. I may die 10 years earlier, but I will die happy and well fed.
Alex
/ September 26, 2008I just read in my local paper yesterday about two restaurant signs next to each other:
(Vegan/Organic Restaurant) “Eat at Jae’s and Live Forever!”
(BBQ Joint): “Eat at Sammy’s and Die Happy!”
Hard to say which is better isn’t it? Still, I like a balanced diet because of the flavors, even though I know its good for me, it’s not my primary reason for why I eat.
Mike
/ September 26, 2008Everytime you eat meat, you make a hippie cry. And you make me happy. First, anything that makes hippies cry is great, and two, since I grew up on the farm and had to deal with every kind of meat in its rawest form, eating meat is tasty revenge for every kick, butt, stomp, bite and stupid “how you be dumb enough to get caught in THAT?!?” moment I have ever dealt with.
Meat: Its fantastic.