Declining testosterone has been widely reported for decades. It would be interesting to see if the same trend is measurable outside the western world - one would suspect not but Coca-Cola and others have wide markets.
https://www.reuters.com/article/health-testosterone-levels-dc-idUKKIM16976320061031
https://academic.oup.com/jcem/article/92/1/196/2598434?searchresult=1
Crude mean TT concentrations, by MMAS study wave (T1, T2, T3) with confidence bands (dotted lines). Estimates are obtained from a generalized additive model with a lowess smoothing term.
