Well we found out since X-mas that one of my friends who has been veggie, slim and fit for 20 years, is 46 years old has terminal cancer. So I have to say, in some cases NO.
I always come back to the “we don’t get issued a best by date”. I do get wound up at times by the “doing this/no doing that” will add 4 years to your life. On a statistical analysis of a population this could well be true. On a person to person case NO ONE can honestly say. We all know that certain things will increase your chances of dying “early” and other things may decrease your chances. The trouble is you don’t have a bench mark for you to base your calculation on.
You pays your money and makes your choice. If being a veggie makes you feel better/happier I say do it. But don’t make yourself miserable for an outcome that you have no real control over.