By Dr. Mercola
Testosterone is an androgenic sex hormone produced by a man's testicles, and to a lesser degree, in smaller amounts, by the ovaries in women. While testosterone is stereotypically associated with virility, it also plays a role in maintaining muscle mass, bone density, red blood cells, and a general sense of well-being.
Beginning around age 30, a man's testosterone levels begin to decline, and continue to do so as time goes on—unless you proactively address your lifestyle.
Chemical exposures, including prescription drugs like statins, can also have an adverse effect on your testosterone production. Symptoms of declining testosterone levels include:
- Decreased sex drive
- Erectile dysfunction and/or problems urinating
- Difficulties with concentration and memory
- Weight gain and/or breast enlargement
According to a recent analysis,1 low testosterone may also increase a man's risk for cardiovascular disease. As reported in the featured article:2
"To arrive at their findings, the research team examined previous studies that analyzed cardiovascular disease and testosterone levels between 1970 and 2013. The review of the studies revealed modest evidence that low testosterone levels are linked to an increased risk of cardiovascular disease.
However, the researchers note there was little evidence of a link between low testosterone and artherosclerosis - the hardening and narrowing of the arteries that can lead to heart attacks and strokes, and there was no evidence of a specific link between heart attacks and testosterone levels."
The Importance of Testosterone for General Health
While the exact mechanism linking low testosterone to heart disease could not be ascertained, the researchers suggest the effect might be related to thrombosis or arrhythmia. Thrombosis is when a blood clot develops, and arrhythmia is basically a condition in which your heart beats erratically. Previous research has linked low testosterone with both of these conditions, plus a number of others, including:
- Increased blood pressure
- Endothelial dysfunction
- Impaired left ventricular function
Interestingly enough however, they also found that testosterone replacement therapy did NOT have any positive effect on cardiovascular health. This could potentially indicate that low testosterone does not in and of itself promote heart disease, but rather that low T and heart disease are both caused by something else. As stated by lead researcher, Dr. Johannes Ruige:3
"Based on current findings, we cannot rule out that low testosterone and heart disease both result from poor overall health."
Indeed, I know first-hand that low testosterone is not an automatic outcome of aging, provided you incorporate certain lifestyle strategies that can naturally boost your testosterone levels, which I'll review below. These strategies are part and parcel of an overall healthy lifestyle, so they also automatically reduce your risk of most chronic disease, including heart disease.
It actually makes logical sense that failure to incorporate these foundational health-promoting strategies could be the root cause of low testosterone, heart disease, and all the heart-related adverse effects listed above.
The Role of Estrogen in the Aging Male
Both men and women make estrogen out of testosterone. As a result, some men can actually end up with close to twice the amount of estrogen found in postmenopausal women. Still, the levels of both testosterone and estrogen both tend to decline with age, and as they do, your body changes. So far, researchers have almost exclusively focused on estrogen's effect on women, and testosterone's impact on men. But that may soon change.
A recent article in the New York Times4 highlighted research demonstrating the intricate play of women's sex hormones in aging men's health—a factor that has so far been largely ignored:
"Estrogen, the female sex hormone, turns out to play a much bigger role in men's bodies than previously thought, and falling levels contribute to their expanding waistlines just as they do in women's. The discovery of the role of estrogen in men is 'a major advance,' said Dr. Peter J. Snyder, a professor of medicine at the University of Pennsylvania, who is leading a big new research project on hormone therapy for men 65 and over. Until recently, testosterone deficiency was considered nearly the sole reason that men undergo the familiar physical complaints of midlife. "
The study in question, published in the New England Journal of Medicine5 (NEJM), found that there were significant individual variations in the amount of testosterone required for any particular man to maintain lean body mass, strength, and sexual function.
However, they were able to determine that testosterone deficiency accounted for decreases in lean mass, muscle size and strength, while estrogen deficiency was the primary culprit when it came to increases in body fat. Both hormones were found to be important for sexual function, and a deficiency in either had a negative impact on the men's libido. According to the lead author, Dr. Joel Finkelstein, an endocrinologist at Harvard Medical School:
"Some of the symptoms routinely attributed to testosterone deficiency are actually partially or almost exclusively caused by the decline in estrogens."
Despite individual variations, Dr. Finkelstein's research offers valuable insight into the function and behavior of estrogen and testosterone at different levels in a man's body. For example, they found that less testosterone is actually needed for muscle maintenance than previously thought. They also found that:
- In young men, the average testosterone level is about 550 nanograms per deciliter (ng/dl)
- Muscle size and strength does not become adversely affected until testosterone levels drop below 200 ng/dl, which has previously been considered extremely low
- Fat accumulation, however, increases at testosterone levels of 300-350 ng/dl, due to its impact on estrogen
- Libido increases steadily with simultaneous increases in testosterone and estrogen
Please note that men are NOT advised to take estrogen replacement therapy, as this could cause feminization, such as enlarged breasts. As your testosterone levels rise, your body will automatically produce more estrogen, so the key is to maintain your testosterone level—ideally by incorporating the strategies I will discuss below.
How to Raise Your Testosterone Levels Naturally Through Exercise
Personally, I do not recommend using testosterone hormone replacement. If you indeed have low testosterone, you can consider trans rectal DHEA cream, which I'll discuss below. DHEA is the most abundant androgen precursor prohormone in the human body, meaning it's the largest raw material your body uses to produce other vital hormones, including testosterone in men and estrogen in women. However, I believe many of you may not even need that, were you to take full advantage of your body's natural ability to optimize hormones like testosterone and human growth hormone (HGH).
Just like testosterone, your HGH levels also sharply decline after the age of 30, as illustrated in the graph above. Both of these hormones are also boosted in response to short, intense exercise. As I do not take any hormone or prohormone supplements, I've been doing Peak exercises for just over three years now, and at the age of 59, my testosterone level (done last month) are still well within the normal range for a young adult male without the aid of ANY prescriptions, hormones and hormone precursor supplements:
- Total testosterone: 982 ng/dl (normal test range: 250-1,100 ng/dl)
- Free testosterone: 117 pg/ml (normal test range: 35-155 pg/ml)
Below is a summary and video demonstration of what a typical high-intensity Peak Fitness routine might look like. As you can see, the entire workout is only 20 minutes, and 75 percent of that time is warming up, recovering or cooling down. You're really only working out intensely for four minutes. It's hard to believe if you have never done this, that you can actually get that much benefit from only four minutes of intense exercise, but that's all you need!
- Warm up for three minutes
- Exercise as hard and fast as you can for 30 seconds. You should feel like you couldn't possibly go on another few seconds
- Recover at a slow to moderate pace for 90 seconds
- Repeat the high intensity exercise and recovery 7 more times
Four Additional Ways to Boost Testosterone and HGH
Besides high intensity exercise, there are several other strategies that will also boost your testosterone levels naturally. These are appropriate for virtually anyone, male or female, as they carry only beneficial "side effects." For even more tips, please see my previous article, "9 Body Hacks to Naturally Increase Testosterone."
- Weight training. When you use strength training to raise your testosterone, you'll want to increase the weight and lower your number of reps. Focus on doing exercises that work a wider number of muscles, such as squats or dead lifts. You can take your workout to the next level by learning the principles of Super-Slow Weight Training. For more information on how exercise can be used as a natural testosterone booster, read my article "Testosterone Surge After Exercise May Help Remodel the Mind."
- Whole body vibration training (WBVT) using a Power Plate. In addition to the Peak Fitness exercises, I do 10 minutes of Power Plate training twice a day and this likely also improved my hormones. WBVT in some ways simulate high intensity exercise by stimulating your white (fast-twitch) muscle fiber. This kick-starts your pituitary gland into making more growth hormone, which helps you build lean body mass and burn fat.
- Address your diet. This is critical for a number of reasons. First of all, if you're overweight, shedding the excess pounds may increase your testosterone levels, according to recent research.6 Testosterone levels also decrease after you eat sugar. This is likely because sugar and fructose raise your insulin level, which is another factor leading to low testosterone. Ideally, keep your total fructose consumption below 25 grams per day. If you have insulin resistance and are overweight, have high blood pressure, diabetes or high cholesterol, you'd be well advised to keep it under 15 grams per day.
The most efficient way to shed excess weight and normalize your insulin levels at the same time is to strictly limit the amount of sugar/fructose and grains in your diet, and replace them with vegetables and healthy fats, such as organic pastured egg yolks, avocado, coconut oil, butter made from raw grass-fed organic milk, and raw nuts.
Saturated fats are in fact essential for building testosterone. Research shows that a diet with less than 40 percent of energy as fat (and that mainly from animal sources, i.e. saturated) lead to a decrease in testosterone levels.7 My personal diet is about 70 percent healthy fat, and other experts agree that the ideal diet includes somewhere between 50-70 percent fat. I've detailed a step-by-step guide to this type of healthy eating program in my optimized nutrition plan.
- Intermittent fasting. Another effective strategy for enhancing both testosterone and HGH release is intermittent fasting. It helps boost testosterone by improving the expression of satiety hormones, like insulin, leptin, adiponectin, glucacgon-like peptide-1 (GLP-1), cholecystokinin (CKK), and melanocortins, which are linked to healthy testosterone function, increased libido, and the prevention of age-induced testosterone decline.
Why I Recommend DHEA Over Testosterone Replacement
If you choose to use hormones it is really crucial to use bioidentical versions. There are synthetic and bioidentical hormone products out on the market, but I advise using bioidentical hormones like DHEA if you opt for this route. DHEA is a hormone secreted by your adrenal glands. Again, this substance is one of the most abundant precursor hormones in your body, and it's crucial for the creation of hormones, including testosterone and other sex hormones.
Production of this prohormone peaks during your late 20s or early 30s. With age, DHEA production begins to decline, right along with your testosterone and HGH levels. Your adrenal glands also manufacture the stress hormone cortisol, which is in direct competition with DHEA for production because they use the same hormonal substrate known as pregnenolone. Chronic stress basically causes excessive cortisol levels, thereby impairing DHEA production, which is why stress is another factor for low testosterone levels.
It's important to use DHEA of any kind strictly under the supervision of a professional. Find a qualified health care provider who will monitor your hormone levels and determine if you actually require supplementation.
Also, rather than using an oral hormone supplementation, I recommend trans-mucosal (vaginal or rectal) application. Skin application may not be wise, as it makes it difficult to measure the dosage you receive. This may cause you to end up receiving more than what your body requires. Applying a trans-mucosal DHEA cream to your rectum (or if you are a woman, your vagina) will allow the mucous epithelial membranes that line your mucosa to perform effective absorption. These membranes regulate absorption and inhibit the production of unwanted metabolites of DHEA. That said, I do NOT recommend prolonged supplementation of hormones, even bioidentical ones. Doing so can trick your body into halting its own DHEA production and may cause your adrenals to become impaired.
Other Helpful Supplements
Besides DHEA, there are also nutritional supplements that can not only address some of the symptoms commonly associated with low testosterone, but may help boost your testosterone levels as well. These include:
- Saw palmetto. Besides addressing symptoms of low testosterone, this herb may also help to actually increase testosterone levels by inhibiting up-conversion to dihydrotestosterone.8 Research has also shown it can help reduce your risk of prostate cancer. When choosing a saw palmetto supplement, you should be wary of the brand, as there are those that use an inactive form of the plant. According to industry expert Dr. Rudi Moerck, what you want to look for is an organic supercritical CO2 extract of saw palmetto oil, which is dark green in color. Since saw palmetto is a fat-soluble supplement, taking it with eggs will enhance the absorption of its nutrients.
- Astaxanthin in combination with saw palmetto. There is also solid research indicating that if you take astaxanthin in combination with saw palmetto, you may experience significant synergistic benefits. A 2009 study published in the Journal of the International Society of Sports Nutrition found that an optimal dose of saw palmetto and astaxanthin decreased both DHT and estrogen while simultaneously increasing testosterone.9
- Ashwagandha. This ancient Indian herb is known as an adaptogen, which can help boost stamina, endurance, and sexual energy. Research published in 201010 found that men taking the herb Ashwagandha experienced a significant increase in testosterone levels.
Ashwagandha also helps promote overall immune function, and can help increase your resistance to occasional stress.11 It also supports healthful levels of total lipids, cholesterol, and triglycerides already in the normal range. While some adaptogens are stimulants in disguise, this is not the case with Ashwagandha. It can give your morning exercise routine a boost, and when taken prior to bed, it can help you get a good night's sleep as well. I recommend using only 100% organic Ashwagandha root, free of fillers, additives and excipients, to ensure quality.
Low Testosterone Is Not an Inevitable Fate for Aging Men
I strongly recommend implementing lifestyle strategies that are known to optimize testosterone levels naturally before you do anything else to address the symptoms associated with low testosterone. If you're still deficient in testosterone after implementing high intensity exercise and strength training, along with the dietary strategies detailed above and, ideally, intermittent fasting, then you could try trans-mucosal DHEA. Again, remember to confer with a qualified health care practitioner and get your levels tested before supplementing with DHEA or any other hormone, including testosterone.
Personally, I've been able to maintain both testosterone and HGH levels comparable to that of a young healthy male, simply by implementing high intensity exercise, Power Plate exercises, and intermittent fasting, along with my standard dietary recommendations. I would strongly encourage you to review my nutrition plan if you haven't already done so.
Add to that some regular sun exposure, and you'll be well ahead of most people. Vitamin D, a steroid hormone, also helps to naturally increase testosterone levels. In one study,12 overweight men who were given vitamin D supplements had a significant increase in testosterone levels after one year. As in most instances, given half a chance, your body will actively and automatically strive to maintain optimal health. So as long as you incorporate the foundational basics of a healthy lifestyle, you can stay healthy and strong well into your old age.