I’ll fall back on my default null hypotheses here.
The effect is probably minimal if it exists at all. If there is any effect, it is probably negligible if you are doing the big things right. Your body is smart, and responds to changes in its environment with an eye towards improved survival and fitness. It is not a simple CICO machine.
you could hypothesize and these rambling thought experiments…or you could watch the video, and see there are several studies saying the effect exists and isn’t minimal
Supposedly this is (of course) a lie/mischaracterization by RFK, that the study is comparing t/sperm levels of kids from the 70s with kids now, and so the kids from the 70s might have had higher levels but now they are in their 60s so…