There is a certain order in the universe. Patterns repeat the way they always have, except when they don’t. Every rule has its exception. Male lactation is an exception to the "got milk" rule in humans.
One known medical condition that can cause lactation in a man or a non parous woman is a prolactin secreting pituitary tumor called a pituitary adenoma or prolactinoma. These tumors can establish the hormonal milieu that leads to the body making milk, because the pituitary gland is the seat of the hormonal control of lactation. Pituitary adenomas are usually not cancerous. It is possible that a man, lactating because of a pituatary tumor, could live a normal lifespan.
Problems other than cancer can exist because of pituitary adenomas. In addition to the secretion of milk there is the possibility of brain compression from a growing tumor. The severity of this problem can vary. If large enough, pituitary adenomas can lead to blindness due to the proximity of the optic nerve to the pituitary gland and even to death if the brain compression is severe enough. On the other hand, these tumors sometimes remain stable at a size that causes lactation but not significant other problems.
Sparse anecdotal reports of men who lactated and who fed infants do exist . Scientific study of the phenomenon does not. One has to wonder if at least some of the anecdotal cases reported in the literature of human males nursing children were not cases of mild to moderate but untreated pituitary adenomas. Published reports are usually of the sensationalizing nature and do not attempt to look at the science behind this rare finding or worse, make claims or recommendations that sound scientific based on ???, they never say.
MEDICATION and HERBS:
Lactation may also be induced by medications or herbs. Phenothiazines, Metaclopromide, Domperidone, estrogen (or phytoestrogens), prolactin, fenugreek, and blessed thistle, all can contribute to initiating and then maintaining lactation in a male (or in a female who has not recently given birth for that matter).
INDUCED LACTATION and RELACTATION:
The phenomena of induced lactation in women who have not recently (or in some cases ever) given birth or relactation in a woman who recently gave birth but whose mammary glandular tissue has involuted to a non or minimally lactating state is well known and better studied. It can be intentionally accelerated through the use of exogenous hormones and/or other medications and/or herbs (typically those mentioned above with the exception of the Phenothiazines) and/or regular, effective stimulation of the areolar/nipple complex. Even the woman who has never been pregnant possesses the basic equipment needed. As milk begins to be produced the regular removal of that milk stimulates more production.
The milk of lactating males has not been studied in terms of its compositional adequacy for raising a child, or at least such studies are not documented in peer reviewed medical journals. It is probably accurate to assume it is similar in composition to the milk of a female who has induced lactation. That has been studied and the medical literature supports it is similar in composition to the milk of a post partum woman.
The interesting and challenging thing about studying the composition of breastmilk however is that breastmilk is not a static fluid. It is constantly changing. This is one of the multitudes of reasons it is superior to any substitute for infant nutrition.
Some of the known ways breastmilk varies are:
Time of day (most hormones and the rate of synthesis vary on a daily circadian rhythm)
Time within a given feeding or expression (foremilk is typically higher in carbohydrates and hind milk is typically higher in fat)
Rate of synthesis (the emptier the breast the faster the synthesis of more milk but the lactating breast is never truly empty of milk as synthesis is constant on at least a base level)
Time since birth (colostrum, the first milk is higher in protein and has less fat, and little to no lactose)
Gestational age of the infant at birth (milk of a mother who has given birth prematurely is higher in protein for the first month or so)
Degree of involution (weaning milk has higher sodium)
Immune factors present (if the mother is exposed to certain illnesses her milk will have more antibodies specific to that illness)
Dietary factors (the type of fat in the mother’s diet influences the type of fat in her milk.
Vitamin content can vary according to mother’s diet
Color, smell and flavor of breastmilk can vary with the mother’s diet. Orange milk after the ingestion of large amounts of Beta-carotene, smoke smelling milk after mother smokes, maple syrup smelling milk when mother takes fenugreek, and babies showing a preference for milk after mothers ingested garlic have all been documented.
The components of breastmilk are currently known at about 300 separate ingredients. It seems new components are always being discovered.
The constant variation in the composition of breastmilk and the fact that we do not have a definitive list of ALL components of breastmilk make proving or disproving the normality of male milk difficult, if not impossible. Having said that, personally I would expect it to be fairly close to female milk in a similar circumstance. There is no logical reason to expect otherwise, but we do not KNOW this as a research based fact.
BREAST DEVELOPMENT male and female:
Embryonic development of the male and female breast is identical. Newborns - both male and female are well known to sometimes secrete a milk commonly called “witches milk” in the first week of life due to the influence of maternal hormones still in circulation in their body. If that milk is expressed production continues so the treatment of the little tykes is to leave them alone. Normal involution of the mammary glandular tissue follows.
The nascent breast remains dormant until it falls under the influence of the hormones of puberty. Girls develop breasts as a normal course of events. Before pregnancy the female breast has some glandular tissue along with fat. Each menstrual cycle furthers glandular development. Pregnancy nearly completes glandular development. The hormonal changes following the birth of the placenta initiate lactation, sometime a bit more glandular developement follows.
The rudimentary breasts of adolescent boys do not normally develop much fat or glandular tissue. When they do, the condition is known as gynecomastia. In adolescence this can be seen most often in overweight boys as excessive fat increases estrogen levels which in turn encourages the development of breasts. For some boys this can be a severe problem and is sometimes treated surgically. For others it is self resolving as adolescent hormones calm or androgen levels overwhelm estrogen levels. Weight loss or stabilization (as height catches up with girth) can also help to reduce gynecomastia.
MAKING MILK all sorts of ways:
In a post partum woman the control of milk production gradually switches from endocrine to autocrine. This means that although hormones return to the non pregnant non postpartum level, if milk removal is regular and effective production can theoretically continue indefinitely. This is how some wet nurses were able to continue producing milk for decades past the birth of their last biological child. It is conceivable that a male, once lactation has ensued could also continue to lactate regardless of the original cause if regular milk removal continued.
Male to female transsexuals or otherwise transgendered individuals may develop breasts (including glandular tissue) with hormonal treatment. There is no reason to think that their breasts could not lactate with adequate stimulation. Certainly it is understandable that such an individual might want to know if her breasts function in terms of lactation and anecdotal reports exist of successful induced lactation just for this purpose. Such an individual may want to nourish their child at the breast as well.
HOWEVER, even in a biologically born female who is inducing lactation the results are not consistent. She has had the benefit of monthly glandular growth since her menarche. It doesn’t always work and if milk is produced it is not always an adequate volume to completely nourish an infant. However, any breastmilk is better than no breastmilk.
SO? just pondering …:
Should a male try to lactate? Suppose he wants to lactate in order to feed a baby? Suppose the mother does not? Is any breastmilk better than no breastmilk in this case? Suppose the mother is lactating adequately. Is the man’s attempt to also feed the baby likely to interfere with the mother’s production (if the baby is the means of stimulating the breast the answer is yes). Could his energies be better placed in assisting the more likely to succeed scenario of the mother lactating? Is this a case that even involves a baby? Does it matter or is this just weird science?
At the Breast
Breastfeeding: A guide for the medical profession
Breastfeeding and Human Lactation
by Riordan and Auerbach
Breastfeeding: Biocultural Perspectives
by Stuart-Macadam and Dettwyler
Breastfeeding the Newborn: Clinical Strategies for Nurses
Dr. Susan Love’s Breast Book
Fresh Milk: The Secret Life of Breasts
Lactation:Physiology, Nutrition, and Breast-Feeding
by Neville and Neifert
Medications and Mothers' Milk
by Thomas Hale
Milk, Money, and Madness: The Culture and Politics of Breastfeeding
http://www.unassistedchildbirth.com/milkmen.htm (cute "Baby Blues" comic strip at the very bottom of this one)
2016 updated resource