What is the relationship between declining hormones and cognitive abilities?
We all know that testosterone levels are linked to your strength, stamina and physical abilities, but does testosterone also impact your “mental might?”
It is common knowledge that memory and cognitive function decline as we age. Do dropping levels of testosterone, and other critical hormones such as HGH, have a negative impact on brain function? Some of the latest research on testosterone and hormone replacement, seems to indicate that is indeed the case.
Both mental acumen, and testosterone levels decline with age, so it seemed fair to assume that this could be related. We know that testosterone is a necessary precursor to the production of certain neurotransmitters, or “brain chemicals.”
Researchers have observed that men who have depressed testosterone levels due to conditions other than ageing, often exhibit the kinds of cognitive difficulties, and memory issues, typical of old age.
A 2006 study published in the European Journal of Endocrinology indicated, “Chemical castration studies in men with prostate cancer suggest that low serum testosterone may be associated with cognitive dysfunction. Low testosterone levels have also been observed in patients with Alzheimer’s disease, and mild cognitive impairment.”
Two years, later the Harvard Men’s Health Watch published a study that indicated a relationship between low-testosterone and age related memory loss. That study went on to conclude that hormone therapy such as testosterone replacement is “promising” for use as a way to delay the onset of, or even reverse, age-related cognitive difficulties.
The Latest Research on Low-T and Cognition
Picking up where these earlier studies left off, a meta-analysis was released in 2016 that found that most men with Alzheimer’s disease and or related dementia, also had low testosterone or Low-T.
According to multiple cross-sectional studies, known as the OPTIMA trials, lower T levels were found in patients with dementia when compared with controls. Significantly lower levels of total testosterone were found in the older males, (average age, 80 years) with Alzheimer’s disease, than in controls. Those with earlier onset Alzheimer’s, (average age, 66 years), also exhibited “free testosterone” levels that were significantly lower than in the controls.
Growth Hormone and Cognitive Decline
Furthermore, it isn’t just testosterone that is linked to cognition. Growth hormone, or HGH levels also decline as you age, and this loss as well can contribute to the cognitive issues typical of ageing.
A 2012 study tested the effects on brain function of a drug, known as Egrifta (Tesamorelin), that stimulates increased production of HGH.
Tesamorelin is already approved by the FDA for use in combating the weight loss that often accompanies victims of HIV/AIDS. It is also indicated for other conditions that may benefit from increasing levels of Growth Hormone, such as obesity and plaque buildup leading to cardiovascular disease.
Basically, Tesamorelin is a synthetic version of something naturally produced by your body known as growth-hormone-releasing hormone, or GHRH. Just as the naturally produced GHRH does, the drug stimulates the production of HGH.
In a 20 week typical double blind study, the researchers found that supplemental GHRH had a positive effect on cognition and healthy brain function. The study’s authors concluded that, “Our results replicate and expand our earlier positive findings, demonstrating that GHRH administration has favorable effects on cognitive function not only in healthy older adults but also in adults at increased risk of cognitive decline and dementia…”
Since the results of that study, the prescribing information for Tesamorelin suggests it may be useful in treating cognitive decline.
Can Hormone Therapy Improve Cognition and Memory?
While more research is needed, it stands to reason that hormone replacement therapy, or HRT, can help improve cognition and memory in males with low testosterone.
There is a lot of anecdotal evidence and testimony from men undergoing HRT that this is true. For many years, in addition to the many physical benefits, men on HRT have reported an increase in “mental clarity.” This is even true of women, who have said that hormone therapy help clear up the “foggy thinking,” typical of menopause.
In fact, I have had patients that have come in seeking hormone replacement therapy specifically for help with cognitive and not physical issues. I remember one fellow, the owner of a fairly large business who was in his 60s, he felt he had “lost his edge,” and could not be the demon in the boardroom he once was. He could not focus on his business, nor negotiate the kinds of deals he could when he started his business years ago, and the company’s bottom line was suffering.
Today, after being one of our HRT patients for a few years, he recently told me he feels “like a Wolf again,” and is “eating the younger guys for breakfast!”