Low Testosterone and Heart Disease Linked—But What’s Really Causing Them?

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
• Depression
• 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:

“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
• Dyslipidemia
• 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:

"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 Times 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 estroge