Optimum Testosterone Levels Give Men the Mental Edge

Noel Peterson, N.D.

We know that optimal levels of the male sex hormone testosterone can play an important role in healthy sexual function in men, especially as they age. Testosterone also appears to improve the function of the brain, and may even help to protect against age-related dementia.

Researchers in the Rancho Bernardo study measured both testosterone and estradiol levels in over 500 men between the ages of 55-89 who were not receiving hormone replacement. Dr. Elizabeth Barrett-Connor and her colleagues at the University of California then compared estrogen and testosterone levels with the men's cognitive performance on various standardized tests.

First, they found that men with lower estrogen levels performed better on two commonly used cognitive function tests. It is interesting that while the sex hormone estrogen is associated with positive cognitive effects in women, it appears to have a reverse effect on men.

Second, they found that men with moderately high levels of bioavailable testosterone scored significantly better in long-term memory and mental control. This relationship was independent of age, education level, alcohol use, and other possible factors influencing cognitive function.

When it comes to testosterone and brain function, more is not always better. While previous studies have linked higher testosterone levels with improved spa-tialization and mathematical skills in men, this study found that as bioavailable testosterone levels increased, cognitive performance followed a bell-shaped curve. At very high or low levels, mental performance declined, "suggesting an optimal hormone level for certain cognitive tasks."

How do sex hormones influence the brain's ability to think? "Sex hormones play a role in the organization of the nervous system and memory," researchers explained, modulating the activity of im-portant neural receptors associated with cognition.

More is not always better, as this study demonstrates. Optimal levels, not simply higher levels, of bioavailable testosterone are associated with increased cognitive ability in aging men. Similarly, other research has shown that testosterone replacement has the greatest clinical efficacy for treating sexual dysfunction in men only when pretreatment levels are low, emphasizing the need for baseline testing.

At the Center, we provide an accurate, convenient assessment that evaluates bioavailable testosterone activity in men. The test is indicated for sex-related dysfunction such as prostate problems, low libido, impotence and hypogonadism, and for use in anti-aging treatment programs to address hormonal imbalances behind increasing fatigue, depression, obesity and cognitive decline. Call the Center for more information.



Source: Barrett-Connor E, Goodman-Gruen D, Patay B. Endogenous sex hormones and cognitive function in older men. J Clin Endocrinol Metab 1999;84(10):3681-85.