A folk medicine adage is that nature always has a purpose. If men produce estrogen, they do so for some specific purpose. Most scientists think estrogen has something to do with the maturation of sperm cells. Others suggest that it may offer some cardiovascular benefits. Indeed, one reason that younger women, who produce the highest levels of estrogen, rarely show significant signs of cardiovascular disease, may be the protection that their higher estrogen levels provide. A recent study traced that to the promotion of COX-2 enzymes, which produce prostacyclin, a prostaglandin that inhibits internal blood clotting linked to heart attacks and strokes.1 The study implies that women who use COX-2 inhibitor drugs to treat joint pain or arthritis are especially vulnerable to cardiovascular complications, possibly even heart attacks or strokes. The same scenario may also occur in men who stay on aromatase-inhibiting drugs too long, but more on that later.
Estrogen boosts levels of high-density lipoprotein (HDL) in women. It also maintains vascular flexibility, along with higher rates of nitric oxide synthesis, which helps control blood pressure. Those protective benefits are apparent, however, only with natural estrogen. Synthetic estrogens—specifically, those given to older women for hormone-replacement therapy—increase the incidence of cardiovascular disease in women who are already at risk of cardiovascular disease because of their declining estrogen levels. That explains why cardiovascular disease shows up mainly in postmenopausal women.
In men synthetic estrogen promotes the internal blood clotting that’s the cornerstone of most heart attacks and strokes. Natural estrogen, however, as produced in a man’s body or in food such as soy, appears to offer protective effects against cardiovascular disease, likely because of the COX-2 effect, along with higher HDL levels and antioxidant effects that estrogen promotes.
From a bodybuilding standpoint, estrogens are considered undesirable. Several types of anabolic steroid drugs, including testosterone, convert to estrogen through the actions of the enzyme aromatase, which converts the normal output of testosterone to estrogen at a rate of about 20 percent daily. It’s found in various parts of the body, including the brain, liver, muscles and particularly in bodyfat, especially peripheral bodyfat stores in legs and arms.
Excess estrogen leads to a number of side effects, including gynecomastia, or male breast development, water retention and increased subcutaneous fat stores, meaning the fat that’s stored just under the skin. Estrogen is even more potent than testosterone in signaling the brain to inhibit gonadotropins, or hormones that control the production of testosterone in the body, mainly luteinizing hormone (LH). The lack of endogenous testosterone production can result in such conditions as lower sperm counts and shrunken testicles.
Bodybuilders who use anabolic steroids are aware of the estrogen problem. In years past they used a drug called tamoxifen citrate, or Nolvadex, which was designed to treat estrogen-responsive breast cancer in older women. Similar in structure to estrogen, Nolvadex could displace estrogen at cellular estrogen receptors. Since Nolvadex exerted weak or no estrogenic activity, by displacing estrogen, it blocked the effects of estrogen at the cellular level.
Many bodybuilders didn’t realize that Nolvadex could either work against estrogen (antagonist) or work like it (agonist). The latter occurred if they used too high a dose or if they took the drug for too long. In addition, Nolvadex blocked two enzymes the testes required for generating testosterone—which led to a further reduction in testosterone.
Not long after Nolvadex became popular, another drug that could be used to block estrogen’s effects was introduced. Called testolactone (Testlac), it worked differently from Nolvadex. Testlac went beyond just blocking the effects of estrogen; it inhibited aromatase. But Testlac was expensive and hard to obtain. Like other aromatase-inhibiting drugs, it also seemed to promote fatigue and lethargy.
Since then far more effective aromatase inhibitors have been introduced, chiefly to treat breast cancer in older women. A few studies, however, show that those drugs can also dramatically increase testosterone levels in men who are clinically low in the hormone. Block aromatase, and you get an automatic boost of testosterone. An added bonus is that the testosterone affected is usually the free, or active, form, the one not bound to blood proteins. Only the free form is biologically available to interact with cellular androgen receptors.
The newest aromatase-inhibiting drugs have trade names such as Arimidex, Aromasin and Femara. They’ve largely displaced such older drugs as Nolvadex, Testlac, Clomid and Cytadren. They’re extremely effective—and very expensive. Arimidex sells for about $10 for a single one-milligram pill.
Cheaper alternatives are available without a prescription. Like the prescription versions, over-the-counter estrogen-blocking supplements block the effects of aromatase. Estrogen-blocking supplements are legal because the main ingredients occur naturally in some foods, and they don’t directly convert into testosterone or other hormones.
On the other hand, if you look at the advertisements for those products, you’ll note that the main benefit touted for them is their ability to increase natural testosterone levels. The health benefits of controlling estrogen are rarely mentioned. The question is whether such supplements work as advertised.
The initial answer to that pertinent question is provided by two recently published studies. The first examined the effects of two unnamed but naturally occurring aromatase inhibitors in 15 men over a 28-day period.2 The ages of the men in the study ranged from 21 to 71, for an average age of 39. None of the subjects had taken any type of testosterone-boosting supplements or medications in the three months prior to the study. The aromatase inhibitors were combined in one capsule, taken as three single caps once daily.
After 10 days total and free testosterone increased by 244 percent and 358 percent from baseline levels. At the 28-day mark total levels had jumped to 314 percent above baseline, while free levels increased to 492 percent. Estrogen, meanwhile, was undetectable in 10 out of 15 subjects by the 10th day. By the 28th day it was undetectable in 13 out of 15 subjects. No significant alterations in lipid, liver or other blood chemistry values occurred in the men while they were using the supplement.
The second study was sponsored by a company that advertises and sells products in the magazines.3 Normally, that sponsorship would raise some degree of skepticism, since the company has something to gain from favorable study results. The study’s scientific protocols, however, were up to par, and there’s no reason to suspect any rigging. Besides, someone has to pay for such studies, and no drug company would, since it’s a natural product; it does have a use patent.
The study featured five men, average age 31, who took four capsules of the aromatase-inhibiting supplement before bed for 28 days. As in the first study, using the supplement significantly increased both total and free testosterone levels. Total test increased 145 percent, 183 percent, 232 percent and 240 percent over the first four weeks of the study. Free test likewise increased from baseline levels, 300 percent, 402 percent, 511 percent and 528 percent during that time. Even so, no significant conversion to estrogen occurred. Blood chemistry tests showed no adverse changes, nor were any other side effects observed.
Some might complain that the small experimental sample—only five subjects—calls the study’s validity into question. On the other hand, it was just a look-see trial to determine whether OTC estrogen inhibitors might be effective. The dramatic results would tempt many to use the supplement year-round, but even the manufacturer advises using it for no longer than eight weeks, then stopping use altogether.
Advice like that makes sense from a health-and-performance perspective because estrogen may have cardiovascular benefits for men, such as helping maintain vital HDL levels. It may also help maintain the androgen receptors without which testosterone is worthless. Plus it has a relationship with growth hormone and insulinlike growth factor 1 (IGF-1); women release greater levels of growth hormone during exercise because of their higher estrogen levels. Indeed, some studies suggest that estrogen protects against excessive muscle breakdown during exercise.
If that doesn’t convince you that estrogen offers men some benefits, consider recent research suggesting that it may play a role in male sexual response. Male mice and rats absolutely need a certain level of estrogen to have normal sexual relations. For humans the picture is less clear, but recent studies of men whose bodies can’t produce aromatase show that they have better sexual response when they get both testosterone and estrogen onboard.4
My Ironman feature on the top 10 food supplements [August ’05], included aromatase-inhibiting supplements on the list. My reasoning was that they appeared to work exactly as advertised. They appear to be a safe way to significantly increase testosterone and, more important, increase free test—the active, true anabolic version of the hormone. OTC aromatase inhibitors offer a good alternative for those who want to increase their testosterone levels while reducing estrogen.
That scenario would appeal to a man of any age, but especially to men 40 or over who are showing lower testosterone and higher estrogen levels. Guys who have higher levels of bodyfat would also likely benefit. That’s because of the link between lots of bodyfat and increased aromatase activity, which equals more conversion of testosterone into estrogen, which in turn signals the brain’s hypothalamus to release less gonadotropin—and even less testosterone. Although it’s still a subject of debate in medicine, the weight of evidence shows that maintaining higher levels of testosterone as they age brings men numerous health benefits, such as maintaining muscle and brain functions.
One other thing to consider about men and estrogen: a recently published study found that stimulating estrogen receptor-B (there are two known estrogen receptors) appears to promote muscular hypertrophy. Stimulating this same estrogen receptor also protects against the onset of prostate cancer by interfering with the "bad" estrogen receptor (estrogen receptor-A) known to promote prostate cancer. Soy works by selectively binding to estrogen B receptors.I would interpret this new research as suggesting that the notion of blocking all estrogen activity in men may not be good for men who seek added muscle and strength.
References
1 Shah, B.H. (2005). Estrogen stimulation of COX-2-derived PGI-2 confers atheroprotection. Trends in Endocrin Metab. 5:199-201.
2 Trimmer, R., et al. (2005). Effects of two naturally occurring aromatase inhibitors on male hormonal and blood chemistry profiles. J Int Soc Sports Nutr. 2:14.
3 Ziegenfuss, T., et al. (2005). Safety and efficacy of a commercially available, naturally occurring, aromatase inhibitor in healthy men. J Int Soc Sports Nutr. 2:28.
4 Carani, C., et al. (2005). Sex steroids and sexual desire in a man with a novel mutation of aromatase gene and hypogonadism. Psychoneuroendocrinology. 30:413-17.
©,2013 Jerry Brainum. Any reprinting in any type of media, including
electronic and foreign is expressly prohibited.
