I'm sure sun exposure also plays a role, everyone wears SPF 8000 sunblock now, while they were putting on tanning oil back in the 50s, 60s, and 70s

Air pollution was worse in the last century https://ourworldindata.org/outdoor-air-pollution

Pollution was worse back then, look up smog in the 70s. We've introduced catalytic converters, emissions standards, etc. Most people now question why we need clean air laws because we have clean air, much like people thinking we don't need vaccines because those diseases aren't around.

https://en.wikipedia.org/wiki/Clean_Air_Act_(United_States)

There's significantly less air and water pollution now than the past, with the only exception being microplastics. We haven't found many short-term impacts from that yet, though

Pollution was probably another contributing factor; I'd be surprised if it wasn't a lot worse in the 60s than it is now: a lot of environmental controls got put in place in the intervening decades. Remember, there was leaded gasoline everywhere, and acid rain scares and the ozone layer depletion in the 80s.

Connery also grew in the wake of WW2, that kind of stress ages you early

It’s a combination of many factors over time. Diet, sun exposure, smoking. Lots of things we have more information about now than we did then. Medicine is better, genetics, etc.

Oh ya, because removing lead from the air made it so much worse. /s