Epidemiological studies have also assessed links between serum testosterone and non-coronary atherosclerosis. A study of over 1000 people aged 55 years and over found an inverse correlation between serum total and bioavailable testosterone and the amount of aortic atherosclerosis in men, as assessed by radiological methods (Hak et al 2002). Increased intima-media thickness (IMT) is an early sign of atherosclerosis and has also been shown to predict cardiovascular mortality (Murakami et al 2005). Cross-sectional studies have found that testosterone levels are negatively correlated with carotid IMT in independently living men aged 74–93 years (van den Beld et al 2003), diabetic men (Fukui et al 2003) and young obese men (De Pergola et al 2003). A 4-year follow up study of the latter population showed that free testosterone was also inversely correlated with the rate of increase of IMT (Muller et al 2004).
The amount of testosterone synthesized is regulated by the hypothalamic–pituitary–testicular axis (see figure to the right). When testosterone levels are low, gonadotropin-releasing hormone (GnRH) is released by the hypothalamus, which in turn stimulates the pituitary gland to release FSH and LH. These latter two hormones stimulate the testis to synthesize testosterone. Finally, increasing levels of testosterone through a negative feedback loop act on the hypothalamus and pituitary to inhibit the release of GnRH and FSH/LH, respectively.
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.6 Also, in order to block the synthesis of excess estrogen (estradiol) from testosterone there are excellent foods and plant extracts that may help to block the enzyme known as aromatase which is responsible producing estrogen. Some of these include white button mushrooms, grape seed extract and nettles.7
A: According to the NIH, normal values for testosterone levels in men can range from 300 to 1,200ng/dL. There can be many different causes of low testosterone including age, diseases, accidents, and medications. Symptoms of low testosterone may include: loss of sex drive, erectile dysfunction, depressed mood, and difficulty concentrating. Low testosterone levels may also bring around body changes including: hair loss, decrease in blood cells possibly leading to anemia, fragile bones, and a decrease in muscle mass. There are different testosterone replacement therapies including patches, such as Androderm; gels, such as Androgel and Testim; and injections, such as testosterone cypionate. Only your health care provider can decide if and what kind of testosterone replacement therapy is appropriate for you. Testosterone replacement therapy is not right for everyone. Patient with certain prostate issues or breast cancer should not take testosterone. For more specific information, consult with your doctor for guidance based on your health status and current medications, particularly before taking any action. Kristen Dore, PharmD
In general, the normal range in males is about 270 to 1070 ng/dL with an average level of 679 ng/dL. A normal male testosterone level peaks at about age 20, and then it slowly declines. Testosterone levels above or below the normal range are considered by many to be out of balance. Moreover, some researchers suggest that the healthiest men have testosterone levels between 400 - 600 ng/dL.
Most Americans today are sleep deprived, which may be a contributing factor to declining testosterone levels in men. See, our body makes nearly all the testosterone it needs for the day while we’re sleeping. That increased level of T that we experience at night is one of the reasons we wake up with “Morning Wood.” (If you don’t have Morning Wood on a consistent basis, you might have low T).
Many studies demonstrate an improvement in mood of hypogonadal men treated with testosterone (Wang et al 1996; Azad et al 2003). The relationship between testosterone status and mood, particularly depression, remains unresolved. Using Beck’s Depression Inventory, Barrett-Connor and colleagues found that the depression score worsened as men aged, exactly at a time when testosterone levels are decreasing (Barrett-Connor et al 1999). Pope and colleagues found that testosterone treatment in men with refractory depression lowered the Hamilton Depression rating scale and the Clinical Global Impression severity rating (Pope et al 2003). The Beck Depression Inventory remained unchanged in Pope’s study.
At the present time, it is suggested that androgen replacement should take the form of natural testosterone. Some of the effects of testosterone are mediated after conversion to estrogen or dihydrotestosterone by the enzymes aromatase and 5a-reductase enzymes respectively. Other effects occur independently of the traditional action of testosterone via the classical androgen receptor- for example, its action as a vasodilator via a cell membrane action as described previously. It is therefore important that the androgen used to treat hypogonadism is amenable to the action of these metabolizing enzymes and can also mediate the non-androgen receptor actions of testosterone. Use of natural testosterone ensures this and reduces the chance of non-testosterone mediated adverse effects. There are now a number of testosterone preparations which can meet these recommendations and the main factor in deciding between them is patient choice.
Vitamin D supplementation may potentially boost testosterone levels, but further research is needed to determine if it really has an effect on the testosterone levels of young people and athletes. The truth is likely similar to zinc and magnesium — being in a deficient state causes your testosterone levels to drop below baseline, and supplementing it just takes you right back to baseline (but not any higher).
Every ingredient can be harmful when taken in significant quantities (we go more into that below), so we pored over each booster’s ingredient list to make sure that they weren’t serving up an overdose. In particular, we took a close look at magnesium and zinc, which have enough scientific background behind them to offer hard upper limits on how much you can safely consume.
"A lot of the symptoms are mirrored by other medical problems," Hedges says. "And for a long time, we were not attributing them to low testosterone, but to diabetes, depression, high blood pressure, and coronary artery disease. But awareness and appreciation of low testosterone has risen. We recognize now that low testosterone may be at the root of problems."