Turns out it's not exactly the caloric restriction that extends the life of people. It's the lowered amount of methionine as a result of the restriction since adequate levels of protein are not provided. Fruits and vegetables have considerably lower amounts of methionine essential amino acid. In large amounts, fruit and veg provide just enough methionine that's not high when consuming enough calories, equal to a calorie restriction SAD diet! The overall methionine content of plant-derived foods is lower than animal-derived foods
Lower methionine intake:
Lower levels of insulin --> lower IGF-1, glucose, and thyroid hormones
Delayed onset of clouding of the lens in the eye (cataracts)
Livers more resistant to oxidative stress
Decreased levels of mitochondrial oxidative damage
Encourages hormesis which leads to less corticosteroids (stress hormone)
Changes in glutathione (glutathione is protective against oxidative damage)
General decline in protein synthesis (may be protective against age-related decline)
In other words, calorie-restrictors cut their methionine intake simply by eating fewer calories...
Which means, when we eat enough calories of fruit and veg, we get low methionine and don't have to calorie restrict.
Of course, methionine is essential, as its biosynthesis provides for non-essential amino acids such as cysteine, carnitine, taurine, and lecithin.
I read about that too in New Scientist once. See a little summary I wrote here:
Good thing a brazil nut, soy protein and sesame flour salad doesn't sound the least bit appetizing! ;)
Soy protein concentrate, sesame flour are not accessible in nature.
Very little amounts of Brazil nuts are needed to exceed 10% fat, not providing enough methionine regardless. I never said that methionine is neccessarily harmful, as it is an essential amino acid, but provides benefit in lower amounts compared to SAD.
Great resource Eli, very good stuff man! It always seemed logical that the less crap you eat ie. calorie restriction, the better, but it just didn't seem like it would apply if you're exlusively eating what your physiologically designed to. It's nice to have a resource backed by science! :)
I provided one sample of a scientific study, you can always proofread and review whether physiological effects via biochemistry are presented correctly. These are two more if you wanted a non-gov source.
It's always intersting to read these things and connect it to our daily lives :)