Re: My two cents
There is more to it than that. People are in closer proximity to each other than they use to be, so viruses are easier to transmit. Same reason that we see more colds and flu when it gets cold than any other time of the year. There is no such thing as cold and flu season, this is just a sales hype tool.
In many ways people tended to be less stressed back in those days and ate healthier including the glands of the animals that could help boost immunity.
They were not taking immune suppressive drugs like Prednisone and cyclosporin.
Antimicrobial spices were used a lot more in the "old days".
And yes, we do have a lot of carcinogens present today, but are they a cause or contributor? Personally, I think many carcinogens actually promote the growth of existing cancers, but do not cause them. For example, xenoestrogens will promote the growth of existing cancers just like our own estrogens can. Our own estrogens do not cause cancers though, they just stimulate the growth of existing cancers.