“Um, why does my son have boobs?”
Parents sometimes ask this question about their newborn babies. After floating around in mom’s estrogen-rich womb for nine months, it’s normal for newborn babies to have little breast buds. This is both normal and temporary, and resolves with time.
What is gynecomastia?
Gynecomastia – or “man boobs,” as it’s more commonly called – is also normal in teenage males. About half of all teenage boys experience gynecomastia at some point during puberty.
As the testicles develop and produce more testosterone, a young man may notice more facial hair, increased muscle mass, a deeper voice, or more oily skin. He may also notice growth of his penis, as well an increased interest in exploring what he can do with it.
Why does gynecomastia happen in puberty?
Although testosterone is described as a male sex hormone, both males and females produce them. The same holds true for estrogen; we typically think of estrogen as a female hormone, but males also have estrogen in their bodies. Rising estrogen levels during puberty result in the growth of breasts in females and can likewise cause transient breast buds in males. This can happen on one or both sides of the chest. The breast tissue may feel a little rubbery, the nipples might feel tingly, and the chest may be tender to touch.
Is it normal?
This is a completely normal, temporary change in males going through puberty. No surgery, medication, or treatment other than reassurance is necessary in most cases. Pubertal gynecomastia almost always resolves within a few months to two years.
There are, however, certain substances that can increase estrogen levels in males, causing gynecomastia to be more dramatic or more persistent.
What else causes gynecomastia?
Certain plants are known as phytoestrogens. Because of their structural similarity with estradiol (a potent form of estrogen), phytoestrogens can mimic the effects of estrogen at receptor sites. For this reason, guys who smoke pot on a regular basis are more likely to have man boobs, even if they’re generally fit. The same goes for guys who drink beer, as beer is made from hops, another potent phytoestrogen.
Soy is another phytoestrogen. Although eating soy products like tofu, edamame, and soymilk on occasion is likely harmless, daily intake of soy products may contribute to gynecomastia. When purchasing soy products, it is best to choose organic: unless labeled otherwise, soy products are almost always genetically modified.
Certain antidepressants and anti-anxiety medications may also cause gynecomastia.
If a young man is overweight, the accumulation of adipose (fat) tissue in the chest can also look like breast tissue. This is called pseudogynecomastia. Exercising, losing weight, and increasing muscle mass will all help burn the fat tissue in the breasts, thus yielding a flatter chest. Furthermore fat produce an enzyme known as aromatase, which converts testosterone to estrogen in the body. This means the more fat you have on your body, the higher your estrogen levels will be. Overweight and obese males therefore typically have higher estrogen levels than thin males, which can result in gynecomastia.
In the overwhelming majority of cases, gynecomastia in teenage males is self-limiting. Staying fit, eating healthy, and avoiding marijuana, beer, and certain pharmaceutical drugs all help speed up the process.