A PERSPECTIVE ON MALE HORMONES:
THE YIN-YANG OF ESTROGEN AND TESTOSTERONE
The following information is adapted with permission from Women’s International
What Does Testosterone Do?Before we go any further with how estrogen and testosterone complement each other, let’s review the various functions of testosterone in men’s health. Testosterone’s effects can be grouped into two categories: androgenic and anabolic. Androgenic refers to the masculinizing or virilizing effects, including the growth of facial and body hair, sex organ development, deepening of the voice, and male pattern baldness. The anabolic effects are those that stimulate the growth of muscle, bone, and red blood cells. The male body systems affected by testosterone include the brain, voice, hair, muscles and fat, organs, bones, and libido (see figure below). The effects of testosterone on these body systems differ during each stage of life. During fetal development, testosterone and its metabolite, dihydrotestosterone or DHT, are necessary for the formation of the internal and external male genitalia. During puberty, testosterone triggers a deepening of the voice, prompts the growth of facial and body hair, stimulates sexual behavior, and initiates sperm production. In adult males, testosterone is necessary to maintain muscle mass and strength, bone mass, normal hair growth, libido, and sperm production.
What is “Normal”?The “normal” range of testosterone levels is quite broad, which is one of the reasons why an excess or deficiency is difficult to detect. The average adult male has somewhere between 260 and 1,000 nanograms (ng) of testosterone per deciliter (dl) of blood plasma. For comparison, the range for women is approximately 50 to 70 ng/dl. While some reference ranges consider male testosterone levels as low as 193 ng/dL to be considered adequate, Life Extension recommends a “moderately youthful” range of between 700 and 900 ng/dL. Each person’s body chemistry is different, such that a person whose testosterone level is at the low end of the range may still have what is needed for development. On the other hand, someone whose testosterone level is at the high end of the range may still have a slight deficiency with respect to his (or her) “normal” level. In addition, for most men, testosterone secretion surges about eight times per day, with the highest peak around 8 am and the lowest level around 10 pm. Men’s testosterone levels do not seem to have a lunar or monthly cycle. Determining what is “normal” is a critical aspect of hormone therapy so that a deficiency or excess can be treated appropriately. Unfortunately, a baseline representing the normal healthy state is rarely available, and the average age-related decline in male testosterone is so slow that it can be difficult to recognize an imbalance. The manifestations of such an imbalance typically depend on the person’s age, as well as the severity and duration of the imbalance. The reality of a male menopause or “andropause” is gradually gaining recognition. Men do experience hormonal changes as they age, and they usually begin to notice these changes around age 40. However, just as women can begin menopause at an earlier age, men can begin to experience changes sooner than that as well. Between the ages of 25 and 50, a man’s testosterone level decreases by approximately 50%, while his estrogen levels, specifically estradiol, increase by 50%. The yin-yang balance still exists, but its shift results in a variety of symptoms.
What are the Symptoms of a Testosterone Deficiency?A testosterone deficiency can be associated with a number of potentially confusing symptoms, which may lead to misdiagnosis or simply remain unexplained. Dr. Thierry Hertoghe believes that a hormone deficiency should be considered when searching for the cause of any chronic or recurrent condition. Because testosterone affects so many different body systems, the symptoms of testosterone deficiency can span a wide range, including changes in physical characteristics, cardiovascular and circulatory problems, mental and emotional troubles, and sexual dysfunction. In addition, the age-related decline of testosterone can be accelerated by many factors, including:
- Excess weight, especially abdominal obesity
- Insulin resistance
- Low HDL cholesterol
- Low bone density
- Illness or disease
- Stressful events
- Depression or mental illness
- Reduced sexual activity.
- Elevated blood pressure
- Increased insulin levels
- Increased cholesterol and triglycerides
- Diminished coronary artery elasticity
- Weakening of the heart muscle
- Increased abdominal fat, which further increases the risk of a heart attack.
- Great timidity
- Inner unrest
- Reduced interest in surroundings
- Loss of ability to concentrate
- Memory failure
- Reduced intellectual agility
- Passive attitudes
- General tiredness
- Weak feeling
- Sexual interest or libido is related to spikes in testosterone levels reaching brain receptors.
- Attraction and arousal can be linked with male and female body odors or pheromones. A male who is low in testosterone will no longer be as pungent after a workout.
- Sexual receptivity is at its height for women when estrogen levels peak during the menstrual cycle. Men’s receptivity is not cyclical, but is more closely related to sexual function.
- Sexual function for men is not as dependent upon testosterone as it is on nitric oxide, which is what keeps the blood vessels in the penis open. However, estrogen and testosterone both play a role in women, which is to maintain the lubrication, sensitivity, and integrity of the vagina, labia, and clitoris.
- Sexual pleasure and sensitivity are heightened for both sexes when testosterone levels peak.
- The experience of sexual orgasmis enhanced for both men and women by testosterone. The pituitary hormone oxytocin rises dramatically as well, enhancing skin and sexual organ sensitivity.
- Sexual fulfillmentis accomplished by the rise in oxytocin (sometimes called the “touchy, feely” hormone). Oxytocin is enhanced by estrogen and antagonized by a high testosterone level.
- Finally, sexual bonding, or love and marriage, is mediated in women by the estrogen-induced enhancement of oxytocin. For men, testosterone activates the pituitary hormone vasopressin, which causes them to pursue females and become territorial.
How Does Estrogen Affect Testosterone?The effects of testosterone are further complicated by its relationship to another sex hormone—estrogen, especially estradiol. As discussed earlier, the yin-yang balance between the estrogen hormones and testosterone is key for both men and women; together, they define our sexuality. Fortunately, the human body is amazingly adept at converting what it has to what it needs. In the male body, an abundant supply of testosterone combines with a plentiful enzyme called aromatase to produce estrogen when and where it is needed. Dr. Shippen believes that “men’s bodies would not have a process for making estrogen if it were useless to them.” He identifies many estrogen-sensitive areas of the male body, including the brain, and explains that estrogen is an extremely important aspect of the brain chemistry that triggers natural sexual functions. He states, “Too little estrogen will neuter a man just as effectively as too little testosterone.” However, for most adult men, the problem is not too little estrogen, but too much! A primary cause of hormone imbalance in men as they age is that testosterone is increasingly converted to estrogen, resulting in an excess of estradiol. Life Extension recommends that men maintain estradiol levels between 21.8 and 30.1 pg/mL. Similar to how women react to minute amounts of testosterone, men have a very small window of optimum effectiveness when it comes to estrogen. Because the estrogen derived from aromatase actually displaces testosterone at the receptor sites, it has the effect of “turning off” testosterone-driven activities or regulating the force of those actions. In this way, estrogen and testosterone exist in a delicate yin-yang balance. Estrogen is necessary to complete the whole, but it also keeps testosterone in check. While men need estrogen to make sexuality possible, it is also the complementary off switch. Unfortunately, that switch can get stuck in the off position. As Shippen puts it, “Like so many things that work well when we are young, the control mechanism aspect of estrogen can get out of hand as we grow older. Illness, drugs, dietary imbalances, lifestyle, and certain aspects of normal aging help accelerate this process and raise estrogen levels to unhealthy heights.” According to Shippen, common causes of elevated estrogen levels in men are:
- Age-related increase in aromatase activity
- Changes in liver function
- Alcohol abuse
- Drug abuse (amphetamines, marijuana, or cocaine)
- Zinc deficiency
- Ingestion of estrogen-enhanced foods or substances
What are the Treatment Options?The scientific and medical literature is ripe with evidence that testosterone therapy can successfully reduce or eliminate most (if not all) of the symptoms mentioned. The benefits of testosterone therapy include increases or improvements in:
- Energy and overall well-being
- Strength and stamina
- Muscle mass
- Bone density
- Body hair and beard growth
- Mood, confidence, self-esteem, and motivation
- Ability to concentrate and focus on tasks
- Libido and sexual function.