Can Men Give Milk? The Riddle of Male Lactation
Recently I have encountered some questions and claims that men can, or may be able to lactate. Now, I had heard of men whose wives have recently had babies lactating a little bit, it would seem because of hormonal changes which have sympathetically taken place in their bodies during their wife's pregnancy.
Newborn male and female babies can also give milk due to the hormones which have been raging through the mother's body which have subsequently been transmitted to the baby in the hours before and during their own birth. This is usually a small amount of milk and dries up quickly, however it proves that we are primed from our very births to be able to give milk whether we are male or female. Indeed, most males and females are born with the necessary equipment to create milk, the mammary glands.
Male lactation can occur when a man is being treated with drugs that stimulate the mammary gland, when he is experiencing hormonal imbalances, when he is under extreme stress (there are reports of prisoners of war producing milk due to the stress and lack of food present in POW camps,) and possibly after stimulation of the breasts.
You don't hear about male lactation much, possibly because it is relatively rare, and possibly because not many men would admit to it had they experienced it. However male lactation is real and possible, even to the point where Darwin himself posited that at one time, both male and female mammals may have been responsible for feeding their young.
The article 'Father's Milk, Male Mammal's Potential For Lactation' (a worthy read if you are interested in the subject) reveals that the 'secret' ingredient involved in all lactation is called 'prolactin, and that it can be released in both male and female mammals.
Prolactin is naturally released in pregnant and nursing women, though production of prolactin can also be caused simply by stimulation. It is a well known fact that women can begin to produce milk after presenting an infant to the breast on several occasions. The evolutionary reasons for this are obvious, if a species is to survive, it is advantageous if any individual is capable of nourishing the young. Women obviously have an easier time of it when it comes to producing milk for their young, though it should be noted that not all women can produce milk. Some women and some men are simply unable to do so. Nowadays infants whose mothers do not produce milk are simply bottle fed, in the past, a wet nurse would have been employed to fulfill the role.
So, yes, males can produce milk, though it is unlikely that a modern human male would be able to produce sufficient milk to provide for an infant, it is possible that he may be stimulated either physically, hormonally, through medication or through terrible environmental conditions to enter lactation and produce male milk.
For more information check out the Wikipedia page on male lactation, as well as the sources.