Too Long; Didn't Read
The impact of what we consume on a daily basis is often only felt many years later — and can be an accident of birth. Life expectancy has increased in most of the world over the last century due to many factors, a big one being lower infant and child mortality. Some populations have a natural advantage in the way they age, as the percentage of a population that is “old” grows larger. The disadvantages are only noticed once enough of the population lives long enough for the dietary effects to be felt.