Um, the article has nothing to do with the health benefits of drinking one over the other, but rather in the energy needed to produce these products.

That being said, anectdotal evidence about your particular grandparents says very little about the relative healthfullness between these products. For a comparison, many smokers live for a very long time, but that doesn't make smoking healthy.

Also if your granparents raised their own chickens and cows, something tells me they did a bit more manual labor than the average american- meaning they burned off a lot of the calories they ate.