"There's no evidence that introducing hormones at levels that existed when you were younger make you live longer," Olshansky said, "This study suggests that you're better off without them."
Testosterone therapy may be recommended for certain men who lack testosterone, Coles said. A source at the National Institutes of Health said a clinical trial is currently underway to see if testosterone is safe and beneficial for elderly men with low testosterone levels.
What advice do experts have for people who want to live to a ripe old age -- and might not be in the frame of mind to consider castration?
Avoid smoking, Coles said, because we know that nicotine is highly addictive and that tobacco smoke causes cancer.
A healthy diet and exercise are also important for longevity, Olshansky said. While there is no universal prescription for exercise, he recommended, "Avoid being horizontal, be vertical, and keep moving!"
But what also really helps when it comes to living longer, he said, is to "choose long-lived parents."