Low Testosterone, Obesity and Alzheimer’s Disease Are Linked

Do not take testosterone supplements! Eat fewer calories instead.

Posted Sep 17, 2014

As men get older two things usually happen: testosterone levels fall and the waistline grows. Testosterone levels fall by about one percent every year after age 30 while obesity among the aged has grown from about 8% in 1980 to about 25% today. These two phenomena negatively influence the normal function of the brain. Low testosterone has been associated with age-associated cognitive impairment which may be due to changes in how neurons interact with each other at the cellular level and whether certain neurons survive exposure to toxins or injury. Furthermore, low testosterone levels are a risk factor for developing Alzheimer’s disease. In men who suffer with diabetes, those who also have low testosterone levels tend to show more neuropathies.

Obesity, particularly in the aged, is a major risk factor for the development of the dreaded metabolic syndrome that includes elevated blood lipids and insulin levels as well as glucose intolerance.  Obesity also increases the level of inflammatory proteins and, ironically, endocrine changes that result in lowered testosterone levels. Obesity coupled with a high fat diet has also been shown to accelerate a decline in thinking, learning and memory and the ability to pay attention.

A recent study published in the Journal of Neuroinflammation by scientists from the University of Southern California investigated the relationship between aging, obesity, low testosterone and mental decline associated with dementia. Simply stated, a high fat diet that leads to obesity will exacerbate the negative consequences of low testosterone upon brain function. The results of the study also indicated that one important feature of brain and body aging, i.e. the impaired regulation of inflammation, links the consequences of obesity and low testosterone levels to Alzheimer’s disease. Interestingly, their study did not find that low testosterone levels significantly affected body weight.

These findings suggest two possible therapeutic approaches: testosterone replacement therapy is controversial, while the other, a caloric restriction diet, is not. Last year a study published in the Journal of the American Medical Association found that testosterone supplements place men at increased risk of death, heart attacks and strokes. Today, the only groups who support using these supplements are the manufacturers who hope to make a profit off ignorance and confusion, regardless of how much risk this brings to the men taking the supplements. We all remember how well this anti-science approach once worked for the tobacco industry.

So what’s an older obese man to do? Do not take testosterone supplements! A much better solution is to lose the excess weight by consuming far fewer calories. Unfortunately, exercise alone is not going to be very effective because low testosterone levels are often associated with muscle weakness and atrophy. Today, an overwhelming body of scientific evidence across a wide spectrum of medical disciplines strongly argues that obesity accelerates the aging process, impairs overall cognitive function and, ultimately, is responsible for numerous processes that kill us. The good news is that the consequences of inflammation due to obesity likely develop slowly and require many years to be fully expressed. Therefore, no matter what your age, the sooner you lose the fat the sooner your brain and body can begin to recover. This risk factor is preventable!

© Gary L. Wenk, Ph.D. Author of Your Brain on Food (Oxford University Press)

TED talk: youtube.com