But they were a hardier group of people with a less toxic environment. They also lived in less densely populated areas, thus reducing the spread of contagious diseases.
During the age of the patriarchs, most people started life with heartier constitutions because the detrimental effects of sin hadn't yet passed thru multiple generations. With each passing generation, the effects became worse.
Other than the results of accidents, assault and warfare, the patriarchs didn't require much medical intervention. We are much more dependent on doctors and hospitals now because our bodies have become so fragile, compared to those of the patriarchs.
Babies that were born with serious genetic problems usually died young, and therefor didn't pass on as many genetic problems to later generations. It's only been since "modern medicine" has kept these children alive into adulthood that these physical hereditary disabilities have increased. In the far past, how many children with diabetes or hemophaelia lived to reproductive age? Now, people are kept alive longer thru artificial means. Long ago, people stayed alive longer thru having less degraded bodies.
If it weren't for modern medical care, our current life spans would probably be a lot less than they are now. Our bodies are on a downward spiral, not an upward rise. The effects of sin over the centuries have progressively broken down the human body, not built it up.
