Life in the Fast Lane Kills: Mitochondria and Longevity

A fascinating interview, and not too technical, by an expert who studies longevity.  Please read the whole thing, but these two excerpts below bring up some interesting concepts that might be counter-intuitive.  The first is that anti-oxidants if taken as a supplement can actually lead to more free radicals.  The second is that fruits and veggies actually confer health benefits, in part, because they have toxins in them (to deter animals from eating them).  This stimulates cell turn over. Exercise, also, increases cell turnover.
So no magic bullets.  Exercise and fruits and vegetables. But don’t load up on antioxidants since they may interfere with the healthy hormetic effect of stress on cells.

They interfere with signaling. We now know that free radicals signal a stress state in the cell. There are all kinds of subtle distinctions, but if something is going wrong, they are behaving like a smoke detector, or at least they are the smoke, and the cell is set up to detect the smoke and react accordingly. The trouble with antioxidants is they’re in effect disabling the smoke detector, and that’s not a good thing to do. The smoke detector sets off a stress response and that stress response changes the expression of all kinds of genes, which are protective for the cell. So very often more free radicals produces a stress response which is protective, which battens down those hatches and allows a cell to go on living for longer. Messing around with that signal by throwing antioxidants at it really doesn’t help…

How might scientists, then, harness the manifold functions of mitochondria to expand human lifespan?

This is tough. The simplest way to replace bad mitochondria with good ones is to induce selection at the level of the cell—cells with bad mitochondria die, those with good mitochondria survive. So the first thing you need is cell turnover. Exercise can do that, even a good diet: Fruit and vegetables may be good for us in part because they contain toxins that stimulate cell turnover, and have little to do with antioxidants. The age-old advice is good—eat well and exercise. But that won’t help us extend our lives much further.