You need to learn the concept of the limiting factor. Drop sugar a bit, longevity goes up. Drop it a lot, longevity doesn't go above the maximum of eighty-ish. Hey, what's up, it looked so promising? Well, you solved the worst problem, but now there's all the other problems.
That's essentially what SENS is: having categorized all the problems that cause age related death, it's possible to attack them all at once. Or more accurately, attack the damage they cause, switching from either a "don't cause damage" (what you're advocating here) or a "cope with damage" (conventional geriatrics) model to a "periodically, repair the damage" one.
It will help the averages by bringing up the bottom and middle, but I think anyone seriously going after SENS doesn't care about that as much as he cares about the outliers (ie himself) who presumably do all that stuff already.
We usually come to life-saving diet decisions in our 30-s or 40-s. Imagine the society where people are not eating junk for the first half of their life. Can any SENS do it?
Then go to state department of health and see the stats, where we can dig the eye-opening data, e.g. all the science of last 50 years added only 4 monthes of longevity for those who are already at their sixties.
Do you beleive any SANS is addressing the right problem? I personally do not.
Diets and exercises are good for damage prevention, when proven, sure. However, they are not damage repair toolkit or maintenance tool for the human body, nor could we replace our hearts, organs, and other damaged parts on demand, like a car mechanics. No matter how well you eat, it is inevitable that our parts will get worn out or starts malfunctioning in old age as a result of cumulative damage.
(Yes, we do have artificial hearts, organs transplants, and so on but they have drawbacks until we improve them...)
