Do I have to starve myself now or is there an age where the benefits really start to kick in?
Most longevity research targets older people because they are the group that is most interested.. and unfortunately by that time it's mostly too late to do anything significant, so of course the best thing is to start now.
If anything you'll benefit more by starting now, because as you get older your body becomes more difficult to change (for lack of a better phrase)
At any rate, forget the research, focus on yourself.
The most important thing you can do is get regular exercise. Use your body, let your body naturally work it's way to better health. A sedentary lifestyle will kill you quicker than anything else.
Second most important thing (IMHO) is trying to limit the amount of stress in your life. Get out of stressful situations, focus on yourself, meditate, don't let yourself get bothered by things that you can't change or aren't worth your time. This is not only good for yourself mentally, but will help your immune system, lower your body's inflammation levels, etc.
If you do these things you'll be well on your way to living a long healthy life. Then you can add whatever other health recommendations come along your way, olive oil, the occasional glass of red wine, etc.
It's like looking at all the classrooms in the US and picking the one with the best grades. Then noticing that there is a higher than normal occurrence of the letter "M" in the students' names. Finally we conclude that using the letter "M" in your child's name will lead to a better outcome in their schooling.
Like I said, I haven't read the paper, but I've seen so many similar studies with biased sampling (or with absolutely no mention of their sampling techniques) that I'm highly suspicious.
While it is interesting (and possibly merits further study), I don't think you will find an answer to your question in your lifetime, unfortunately. Experiments that would provide good results will take a long time, if they are ever even attempted.