Oh, good heavens! It cracks me up. No one my age should have lived over 40 by some health standards. I'm not saying to go out of your way to do things that are unhealthy, but I never ate butter as a child, and my parents (77 and 81) rarely do. Margarine is what we could afford, and that is what we had. I also, as every person I know over the age of 40, lived in homes with asbestos in floors and ceilings and lead in walls and cupboards. Yet we're living longer than our "all natural" grandparents did, and it seems that children now, who live with newer safety measures, have more medical problems that children did when I was young. Yes, some of that is simply that we didn't know about a kid across the country or world who died of these problems.
Yes, do your best by your family by whatever means. Every body is individual. What will kill one person won't hurt another, with obvious exceptions (don't think anyone ever benefited from a heroin or tobacco addiction) you can only do the best you can.