Checkup: Why Low Testosterone for New Dads?
Time now for this weekís Sound Medicine Checkup. You may have heard of the recent study that found lower testosterone levels among new dads. Sound Medicineís somewhat concerned contributor Eric Metcalf takes a closer look.
So this study followed 600 guys, and it found that not only were the guys with high testosterone more likely to have a partner and a kid four years later, these new daddies had bigger declines in testosterone than the guys who didnít become fathers.
The upshot was that these hormone-deprived daddies might be too busy updating the stick-figure families on the back window of the SUV to go out looking for opportunities to make more babies. But not so fast, says Abraham Morgentaler, a Harvard urologist and author of the book Testosterone for Life.
"We have this idea that is totally mistaken but seems to be assumed by even very accomplished scientists, that a manís behavior is influenced moment by moment almost by what his testosterone level is, and itís simply not true.
The truth is that men have wide variability in their testosterone levels every single day, even the healthiest guys, and especially younger men. As long as guys have a testosterone level within a normal range, which we talk about is somewhere between 350 to 1,000 nanograms per deciliter, you cannot tell the difference in behavior between a guy whose testosterone is 900 compared to a guy whose testosterone is 400."
So if washing baby bottles and wearing barf-stained shirts doesnít shrink your manly testosterone levels, what could explain this finding?
"The whole issue is not whether the testosterone was lowered in some kind of evolutionary way to make these men become better fathers, which I think is the thrust of what the authors were trying to conclude. Loss of sleep, or disordered sleep, can substantially drop testosterone. As can stress. So itís entirely possible, and in my opinion likely, that the young fathers werenít sleeping as well and thatís why their testosterone was lower."
Of course, testosterone does decline with age, and certain medical conditions can be linked to a drop, such as diabetes. Truly low testosterone can lead to a litany of maladies. But thatís another story. So new dads, put on your fanny packs with pride, and keep wearing your ďBecause Iím the Daddy, Thatís WhyĒ t-shirts. We all still know youíre the man.