Now that we know chronic insulin spikes lead to lower Testosterone production, I hope I haven’t sent you running into the low carb camp! There are a few studies out there showing that long term low carb or ketogenic dieting leads to higher cortisol levels (especially with subjects who are training), and decreased testosterone levels (28 & 29). I have used low carb diets in the past with successful results (winning a national bodybuilding title), however the key is to use cyclical carb re-feeds. If you’re going to go on a low carb diet for whatever reason, be sure to work in a large carb reefed once a week.
If men’s brain, muscles, and bones are being affected daily due to low testosterone, and it is what makes men, men, why aren’t we doing more about this serious health problem? Could there be a political correctness crept in the scientific community that is hindering newly invigorated research in this area? I thought that scientific inquiry suppose to go where the evidence leads. It appears that some honest experts are opening their eyes to this truth.
Intramuscular testosterone injections were first used around fifty years ago. Commercially available preparations contain testosterone esters in an oily vehicle. Esterification is designed to retard the release of testosterone from the depot site into the blood because the half life of unmodified testosterone would be very short. For many years intramuscular preparations were the most commonly used testosterone therapy and this is still the case in some centers. Pain can occur at injection sites, but the injections are generally well tolerated and free of major side effects. Until recently, the available intramuscular injections were designed for use at a frequency of between weekly and once every four weeks. These preparations are the cheapest mode of testosterone treatment available, but often cause supraphysiological testosterone levels in the days immediately following injection and/or low trough levels prior to the next injection during which time the symptoms of hypogonadism may return (Nieschlag et al 1976). More recently, a commercial preparation of testosterone undecanoate for intramuscular injection has become available. This has a much longer half life and produces testosterone levels in the physiological range throughout each treatment cycle (Schubert et al 2004). The usual dose frequency is once every three months. This is much more convenient for patients but does not allow prompt cessation of treatment if a contraindication to testosterone develops. The most common example of this would be prostate cancer and it has therefore been suggested that shorter acting testosterone preparations should preferably used for treating older patients (Nieschlag et al 2005). Similar considerations apply to the use of subcutaneous implants which take the form of cylindrical pellets injected under the skin of the abdominal wall and steadily release testosterone to provide physiological testosterone levels for up to six months. Problems also include pellet extrusion and infection (Handelsman et al 1997).
The final two studies looked directly at soy vs testosterone levels. The first looked at introducing consumption of soya flour on testosterone levels. They found that those who ate the Soy flour lowered their T levels during the study (43). And the second study looked at the consumption of soy protein isolates (powder) in healthy men. They found that testosterone levels decreased upon consumption of soy powder (45).
More recently, a study from 2015 noted that consuming 600mg daily of standardized fenugreek extract for eight weeks increased free testosterone levels compared to placebo. The test group also experience an increase the the number of repetitions the could perform in the leg press before reaching failure. And, to top it off, subjects receiving the fenugreek supplement dropped body fat without losing strength.
We also have epidemiologic studies, like the Physicians’ Health Study, the Baltimore Longitudinal Study of Aging, and the Massachusetts Male Aging Study, that include tens of thousands of men who are followed for 5, 10, 15, or even 20 years. At the end of the study period, the researchers see who developed prostate cancer and who didn’t. They can then look at blood samples taken at the start of the study to see if, for example, the group that got prostate cancer had a higher level of testosterone over all. About 500,000 men have been entered in some 20 trials of this type around the world. Not one of those studies has shown a definitive correlation between prostate cancer and total testosterone. Three or four have shown weak associations, but none of those have been confirmed in subsequent studies.
Studies of the effects on cognition of testosterone treatment in non-cognitively impaired eugonadal and hypogonadal ageing males have shown varying results, with some showing beneficial effects on spatial cognition (Janowsky et al 1994; Cherrier et al 2001), verbal memory (Cherrier et al 2001) and working memory (Janowsky et al 2000), and others showing no effects (Sih et al 1997; Kenny et al 2002). Other trials have examined the effects of testosterone treatment in older men with Alzheimer’s disease or cognitive decline. Results have been promising, with two studies showing beneficial effects of testosterone treatment on spatial and verbal memory (Cherrier et al 2005b) and cognitive assessments including visual-spatial memory (Tan and Pu 2003), and a recent randomized controlled trial comparing placebo versus testosterone versus testosterone and an aromatase inhibitor suggesting that testosterone treatment improves spatial memory directly and verbal memory after conversion to estrogen (Cherrier et al 2005a). Not all studies have shown positive results (Kenny et al 2004; Lu et al 2005), and variations could be due to the different measures of cognitive abilities that were used and the cognitive state of men at baseline. The data from clinical trials offers evidence that testosterone may be beneficial for certain elements of cognitive function in the aging male with or without cognitive decline. Larger studies are needed to confirm and clarify these effects.
Consuming high amounts of sugary foods raises your blood glucose levels, which causes your body to release insulin as a response to the raised blood glucose levels. If not managed correctly, the body begins to develop a tolerance to insulin and cannot absorb the sugars in the blood stream as it used to, causing you to become insulin resistant. Being insulin resistant releases cortisol, and as you know, cortisol has extremely negative effects, lowering testosterone by quite a bit.
There are pills in the United States for testosterone supplementation, but their use is strongly discouraged because they cause significant liver toxicity. A safe oral formulation called testosterone undecanoate is available in Canada and in Europe, but not in the United States. What’s quite exciting is that an injectable version of testosterone undecanoate (Nebido) was submitted to the FDA for approval in August 2007. (It’s already approved in many other countries.) It lasts for 12 weeks, so a patient could come in and get a shot about four times a year. [Editor’s note: In December 2009, the brand name of the drug in the United States was changed to Aveed. As of January 2011, it was still awaiting FDA approval.]
Testosterone may fight depression. If you’ve been battling the black dog of depression, it may be because of low testosterone levels. Researchers have found that men suffering from depression typically have deficient testosterone levels. While scientists haven’t been able to figure out whether it’s low testosterone that causes depression or if depression causes low T levels, preliminary research has shown that some men suffering depression report improvement in mood and other factors of depression after undergoing doctor-directed testosterone treatments.
Men who have prostate cancer or breast cancer should not take testosterone replacement therapy. Nor should men who have severe urinary tract problems, untreated severe sleep apnea or uncontrolled heart failure. All men considering testosterone replacement therapy should undergo a thorough prostate cancer screening -- a rectal exam and PSA test -- prior to starting this therapy.