- 1 What Causes Gynecomastia?
- 1.1 Physiological Gynecomastia
- 1.2 Pharmacological Gynecomastia – Drugs that Cause Gynecomastia
- 1.3 Pathological Gynecomastia
What Causes Gynecomastia?
Gynecomastia is a benign proliferation of male breast tissue triggered by an imbalance between the stimulatory effect of estrogen and inhibitory effect of androgens on breast tissue and is a general reflection of the relative estrogen to androgen ratio in the body. This can either be attributed to increased estrogen synthesis, reduced androgen production, or an amalgamation of both.
The causes of gynecomastia have been traditionally divided into three categories depending on the mechanism involved. These categories are responsible for different types and grades of gynecomastia and include:
- Physiological causes,
- Pharmacological causes and
- Pathological causes.
Physiological gynecomastia, as the name suggests, is development of man boobs due to normal processes occurring in the body. It is relatively common, with a prevalence rate as high as 36%. In fact, most cases of unilateral as well as asymmetric gynecomastia occur due to physiological rather than pathological processes.
Newborn Male Breast Enlargement
Physiological gynecomastia is often seen in both male and female newborns as a residual effect of androgens to estrogens conversion by the placenta. This temporary gynecomastia usually subsides within two to three weeks.
Gynecomastia in Puberty
Adolescents between 10-12 years of age are also prone to developing physiological gynecomastia. Gynecomastia in boys is usually the result of a surge in the levels of estradiol and testosterone, with the former reaching much higher levels than the latter.
What is Senescent Gynecomastia?
Aged men, owing to decrease in testosterone and a relative increase in the fatty tissue (which converts androgens to estrogens), may experience senescent gynecomastia.
These individuals may concomitantly have pathological processes which may act in conjunction with the physiological processes to cause development of man boobs.
Zinc Deficiency and Gynecomastia
Other causes of physiological gynecomastia include malnutrition in the form of both starvation and obesity. This is especially true in the case of zinc deficiency, which is known to facilitate aromatization of testosterone to estrogens.
Does Soy Cause Man Breasts?
In contrast, excess consumption of foods containing estrogen-like substances known as phytoestrogens may also cause gynecomastia. These include soy products which are particularly high in phytoestrogens, along with other legumes and certain red meats obtained from animals fed artificial hormones.
Pharmacological Gynecomastia – Drugs that Cause Gynecomastia
More than 25% of all cases of man boobs are due to direct or indirect consequences of drug use. Medications that cause gynecomastia are diverse and include the ketoconazole, human chorionic gonadotropin (hCG), human growth hormone (hGH), gonadotropin-releasing hormone analogs, calcium channel blockers (e.g. verapamil, amlodipine) and anti-peptic ulcer drugs such as cimetidine. Herbal products and natural supplements such as lavender oil and Tribulus terrestris have also been implicated.
Gynecomastia Caused by Spironolactone
Spironolactone, a steroidal drug prescribed for hypertension or heart failure, is undoubtedly the prototype drug for drug induced gynecomastia. The mechanism behind development of man boobs as a due to spironolactone usage occurs as a result of binding to androgen receptors and lowering circulating androgens.
Does Omeprazole Cause Gynecomastia?
Prilosec (omeprazole), a drug which is prescribed for heartburn and gastric reflux, is also known to cause gynecomastia by inhibiting enzymes that are involved in the metabolism of estrogens, thereby causing increased levels in the blood.
Gynecomastia Caused by Risperdal
Risperdal (risperidone) is a second-generation atypical antipsychotic drug primarily used in the management of schizophrenia, bipolar disorder and autism.
Risperdal acts as an antagonist at dopamine receptors, and inhibition of dopamine action is associated with a consequent increased levels of prolactin in the blood, a hormone that normally promotes breast development milk production in women.
High levels of prolactin can, in turn, lead to galactorrhea, infertility, gynecomastia and reduced bone mineral density in men.
Other Drugs that Cause Male Breast Enlargement
Antidepressants such as Zoloft (sertraline) have also been implicated in the development of gynecomastia mediated by alterations in the levels of dopamine via mechanisms similar to those discussed before.
Another class of drugs that is often mentioned in relation to development of man boobs are those used in the management of benign prostatic hyperplasia and prostate cancer.
Among these, 5-alpha-reductase inhibitors such as Propecia (finasteride) and dutasteride take the limelight, along with antiandrogens such as bicalutamide and estrogen therapy.
Propecia, also prescribed for the treatment of male pattern baldness, decreases the conversion of testosterone to its active metabolite dihydrotestosterone, causing increased conversion of testosterone to estrogens in peripheral tissues thereby leading to gynecomastia.
Majority of cases of gynecomastia in bodybuilders are due to use of synthetic anabolic steroids. Gyno from steroids such as Winstrol (stanozolol) occurs as a result of increased androgens in the body which are inevitably aromatized to estrogens in peripheral tissue, thereby disturbing the balance between the two.
What Causes Gynecomastia in Bodybuilders?
The severity of gynecomastia in bodybuilders is associated with the duration and dosage. Extreme gynecomastia is often observed with long-term use of anabolic steroids, and may prove to be counter-productive for these gym fanatics.
Similarly, bodybuilders using human growth hormone can experience gynecomastia due to similar mechanisms.
A common misconception in bodybuilders is that creatine supplements cause gynecomastia. Use of creatine supplements may cause retention of water, which may look like man boobs but, in actuality, are not as there is no development of glands.
How does Alcohol Cause Gynecomastia?
Alcohol abuse is also associated with the development of gynecomastia. Excessive alcohol consumption lowers testosterone levels in the blood, promotes aromatization of androgens to estrogens and causes hypogonadism, all of which have been linked with the development of gynecomastia.
Other drugs of abuse such as marijuana and amphetamines have also been implicated in the development of man boobs. Smoking weed may cause gynecomastia by decreasing testosterone levels and reducing testicular size. Use of Adderall may cause man boobs by similar mechanisms
Pathological gynecomastia is defined as the development of man boobs in patients with a pre-existing disease such as liver failure or cirrhosis, kidney failure, testicular tumors e.g. Leydig/Sertoli cell tumors, or hCG-secreting choriocarcinoma.
Tumors that arise in other glands and are involved in disturbing the androgen-estrogen hormonal balance, may also result in gynecomastia. These include, but are not limited to, pituitary gland tumors, adrenocortical tumors, and bronchogenic carcinoma.
Hyperthyroidism can also cause development of male breasts. Thyroid hormones have been known to have a role in stimulating the liver to produce a sex hormone binding protein. This protein causes increased binding of testosterone relative to estradiol, resulting in a decrease in free testosterone relative to estrogen.
Gynecomastia is also a feature of Klinefelter Syndrome, a genetic disorder caused by an extra X chromosome. These individuals have low testosterone levels, high FSH and LH, and may suffer from hypogonadism, all of which are implicated in the development of gynecomastia.
Most cases of gynecomastia are managed conservatively. Surgical or medical management is warranted if conservative management fails.
Medicine for gynecomastia includes aromatase inhibitors that include testolactone and selective estrogen receptor modulators such as tamoxifen and raloxifene, although the latter have not been approved by FDA.
Gynecomastia gland removal via surgery is often reserved for chronic severe gynecomastia that does not respond to medical therapy. Temporary options such as compression shirts are also used frequently.