feels like a correlation/causation thing once again. If you are in good enough health to lift weights at an older age by definition you are healthier because you aren't suffering from a debilitating illness. People who are dedicated enough to lift weights are also probably following a much better diet than the average person

regardless it's good to see strength training getting some love instead of the cult of cardio. People associating fitness/working out with misery on a treadmill is why so few people workout