Could the low testosterone problem be a mirage?

Low testosterone (a.k.a. “low T”) is caused by worn out glands no longer able to secrete enough T, right? At least this seems to be the most prevalent theory today, a theory that reminds me a lot of the “tired pancreas” theory () of diabetes. I should note that this low T problem, as it is currently presented, is one that affects almost exclusively men, particularly middle-aged men, not women. This is so even though T plays an important role in women’s health.

There are many studies that show associations between T levels and all kinds of diseases in men. But here is a problem with hormones: often several hormones vary together and in a highly correlated fashion. If you rely on statistics to reach conclusions, you must use techniques that allow you to rule out confounders; otherwise you may easily reach wrong conclusions. Examples are multivariate techniques that are sensitive to Simpson’s paradox and nonlinear algorithms; both of which are employed, by the way, by modern software tools such as WarpPLS (). Unfortunately, these are rarely, if ever, used in health-related studies.

Many low T cases may actually be caused by something other than tired T-secretion glands, perhaps a hormone (or set of hormones) that suppress T production; a T “antagonist”. What would be a good candidate? The figure below shows two graphs. It is from a study by Starks and colleagues, published in the Journal of the International Society of Sports Nutrition in 2008 (). The study itself is not directly related to the main point that this post tries to make, but the figure is.



Look at the two graphs carefully. The one on the left is of blood cortisol levels. The one on the right is of blood testosterone levels. Ignore the variation within each graph. Just compare the two graphs and you will see one interesting thing – cortisol and testosterone levels are inversely related. This is a general pattern in connection with stress-induced cortisol elevations, repeating itself over and over again, whether the source of stress is mental (e.g., negative thoughts) or physical (e.g., intense exercise).

And the relationship between cortisol and testosterone is strong. Roughly speaking, an increase in cortisol levels, from about 20 to 40 μg/dl, appears to bring testosterone levels down from about 8 to 5 ηg/ml. A level of 8 ηg/ml (the same as 800 ηg/dl) is what is normally found in young men living in urban environments. A level of 5 ηg/ml is what is normally found in older men living in urban environments.

So, testosterone levels are practically brought down to almost half of what they were before by that variation in cortisol.

Chronic stress can easily bring your cortisol levels up to 40 μg/dl and keep them there. More serious pathological conditions, such as Cushing’s disease, can lead to sustained cortisol levels that are twice as high. There are many other things that can lead to chronically elevated cortisol levels. For instance, sustained calorie restriction raises cortisol levels, with a corresponding reduction in testosterone levels. As the authors of a study () of markers of semistarvation in healthy lean men note, grimly:

“…testosterone (T) approached castrate levels …”

The study highlights a few important phenomena that occur under stress conditions: (a) cortisol levels go up, and testosterone levels go down, in a highly correlated fashion (as mentioned earlier); and (b) it is very difficult to suppress cortisol levels without addressing the source of the stress. Even with testosterone administration, cortisol levels tend to be elevated.

Isn't possible that cortisol levels go up because testosterone levels go down - reverse causality? Possible, but unlikely. Evidence that testosterone administration may reduce cortisol levels, when it is found, tends to be rather weak or inconclusive. A good example is a study by Rubinow and colleagues (). Not only were their findings based on bivariate (or unadjusted) correlations, but also on a chance probability threshold that is twice the level usually employed in statistical analyses; the level usually employed is 5 percent.

Let us now briefly shift our attention to dieting. Dieting is the main source of calorie restriction in modern urban societies; an unnatural one, I should say, because it involves going hungry in the presence of food. Different people have different responses to dieting. Some responses are more extreme, others more mild. One main factor is how much body fat you want to lose (weight loss, as a main target, is a mistake); another is how low you expect body fat to get. Many men dream about six-pack abs, which usually require single-digit body fat percentages.

The type of transformation involving going from obese to lean is not “cost-free”, as your body doesn’t know that you are dieting. The body “sees” starvation, and responds accordingly.

Your body is a little bit like a computer. It does exactly what you “tell” it to do, but often not what you want it to do. In other words, it responds in relatively predictable ways to various diet and lifestyle changes, but not in the way that most of us want. This is what I call compensatory adaptation at work (). Our body often doesn’t respond in the way we expect either, because we don’t actually know how it adapts; this is especially true for long-term adaptations.

What initially feels like a burst of energy soon turns into something a bit more unpleasant. At first the unpleasantness takes the form of psychological phenomena, which were probably the “cheapest” for our bodies to employ in our evolutionary past. Feeling irritated is not as “expensive” a response as feeling physically weak, seriously distracted, nauseated etc. if you live in an environment where you don’t have the option of going to the grocery store to find fuel, and where there are many beings around that can easily kill you.

Soon the responses take the form of more nasty body sensations. Nearly all of those who go from obese to lean will experience some form of nasty response over time. The responses may be amplified by nutrient deficiencies. Obesity would have probably only been rarely, if ever, experienced by our Paleolithic ancestors. They would have never gotten obese in the first place. Going from obese to lean is as much a Neolithic novelty as becoming obese in the first place, although much less common.

And it seems that those who have a tendency toward mental disorders (e.g., generalized anxiety, manic-depression), even if at a subclinical level under non-dieting conditions, are the ones that suffer the most when calorie restriction is sustained over long periods of time. Most reports of serious starvation experiments (e.g., Roy Walford’s Biosphere 2 experiment) suggest the surfacing of mental disorders and even some cases of psychosis.

Emily Deans has a nice post () on starvation and mental health.

But you may ask: What if my low T problem is caused by aging; you just said that older males tend to have lower T? To which I would reply: Isn’t possible that the lower T levels normally associated with aging are in many cases a byproduct of higher stress hormone levels? Take a look at the figure below, from a study of age-related cortisol secretion by Zhao and colleagues ().



As you can see in the figure, cortisol levels tend to go up with age. And, interestingly, the range of variation seems very close to that in the earlier figure in this post, although I may be making a mistake in the conversion from nmol/l to ηg/ml. As cortisol levels go up, T levels should go down in response. There are outliers. Note the male outlier at the middle-bottom part, in his early seventies. He is represented by a filled circle, which refers to a disease-free male.

Dr. Arthur De Vany claims to have high T levels in his 70s. It is possible that he is like that outlier. If you check out De Vany’s writings, you’ll see his emphasis on leading a peaceful, stress-free, life (). If money, status, material things, health issues etc. are very important for you when you are young (most of us, a trend that seems to be increasing), chances are they are going to be a major source of stress as you age.

Think about individual property accumulation, as it is practiced in modern urban environments, and how unnatural and potentially stressful it is. Many people subconsciously view their property (e.g., a nice car, a bunch of shares in a publicly-traded company) as their extended phenotype. If that property is damaged or loses value, the subconscious mental state evoked is somewhat like that in response to a piece of their body being removed. This is potentially very stressful; a stress source that doesn’t go away easily. What we have here is very different from the types of stress that our Paleolithic ancestors faced.

So, what will happen if you take testosterone supplementation to solve your low T problem? If your problem is due to high levels of cortisol and other stress hormones (including some yet to be discovered), induced by stress, and your low T treatment is long-term, your body will adapt in a compensatory way. It will “sense” that T is now high, together with high levels of stress.

Whatever form long-term compensatory adaptation may take in this scenario, somehow the combination of high T and high stress doesn’t conjure up a very nice image. What comes to mind is a borderline insane person, possibly with good body composition, and with a lot of self-confidence – someone like the protagonist of the film American Psycho.

Again, will the high T levels, obtained through supplementation, suppress cortisol? It doesn’t seem to work that way, at least not in the long term. In fact, stress hormones seem to affect other hormones a lot more than other hormones affect them. The reason is probably that stress responses were very important in our evolutionary past, which would make any mechanism that could override them nonadaptive.

Today, stress hormones, while necessary for a number of metabolic processes (e.g., in intense exercise), often work against us. For example, serious conflict in our modern world is often solved via extensive writing (through legal avenues). Violence is regulated and/or institutionalized – e.g., military, law enforcement, some combat sports. Without these, society would break down, and many of us would join the afterlife sooner and more violently than we would like (see Pinker’s take on this topic: ).

Sir, the solution to your low T problem may actually be found elsewhere, namely in stress reduction. But careful, you run the risk of becoming a nice guy.

Ancestral Health Symposium 2012: Evolutionarily sound diets and lifestyles may revolutionize health care

The Ancestral Health Symposium 2012 was very interesting on many levels. Aaron Blaisdell and the team of volunteers really did a superb job at organizing the Symposium. Boston is a great city with an excellent public transportation system, something that is always great for meetings, and a great choice for the Symposium. Needless to say, so was Harvard. Even though the program was packed there were plenty of opportunities to meet and talk with several people during the breaks.

We had our panel “New Technologies and New Opportunities”, which Paul Jaminet moderated. The panelists were Chris Keller, Chris Kresser, Dan Pardi, and myself. The first photo below, by Bobby Gill, shows Chris Keller speaking; I am on the far left looking at the screen. The second photo, by Beth Mazur, shows all the panelists. The third photo, also by Bobby Gill, shows a group of us talking to Stephan Guyenet after his presentation.

I talked a bit toward the end of the panel about the importance of taking nonlinearity into consideration in analyses of health data, but ended up being remembered later for saying that “men are women with a few design flaws”. I said that to highlight the strong protective effect of being female in terms of health, which was clear from the model I was discussing.

There is a good evolutionary reason for the protective effect of being female. Evolution is a population phenomenon. Genes do not evolve; neither do individuals. Populations evolve through the spread or disappearance of genotypes. A healthy population with 99 men and 1 woman will probably disappear quickly, and so will its gene pool. A healthy population with 99 women and 1 man will probably thrive, even with the drag of inbreeding depression. Under harsh environmental conditions, the rate of female-to-male births goes up, in some cases quite a lot.

I was able to talk to, or at least meet briefly face-to-face with, many of the people that I have interacted with online on this blog and other blogs. Just to name a few: Miki Ben-Dor, Aaron Blaisdell, Emily Deans, Andreas Eenfeldt, Glenn Ellmers, Benjamin Gebhard, Stephan Guyenet, Dallas Hartwig, Melissa Hartwig, Paul Jaminet, Chris Keller, Chris Kresser, Mathieu Lalonde, Robert Lustig, Chris Masterjohn, Beth Mazur, Denise Minger, Jimmy Moore, Katherine Morrison, Richard Nikoley, Dan Pardi, Kamal Patel, David Pendergrass, Mark Sisson, Mary Beth Smrtic, J. Stanton, Carlos Andres Toro, and Grayson Wheatley.

It would have been nice to have Peter (from Hyperlipid) there, as I think a lot of the attendants are fans. I attended Jamie Scott’s very interesting talk, but ended up not being able to chat with him. This is a pity because we share some common experiences – e.g., I lived in New Zealand for a few years. I did have the opportunity to talk at some length with J. Stanton, who is an inspiration. It was also great to exchange some ideas with my panelists, Miki Ben-Dor, Emily Deans, Stephan Guyenet, Chris Masterjohn, Kamal Patel, and David Pendergrass. I wish I had more time to talk with Denise Minger, who is clearly a very nice person in addition to being very smart. Talking about a smart person, it was also nice chatting a bit with Richard Nikoley; a successful entrepreneur who is in the enviable position of doing what he feels like doing.

I could not help but notice a tendency among some participants (perhaps many, judging from online threads) to pay a lot of attention to how other people looked in a very judgmental way. That person is too fat, his/her face is too red, she/he looks too old etc. So was this supposed to be the Ancestral Health Pageant 2012? There is nothing wrong with looking good. But many people adopt an evolution-inspired lifestyle because they are quite unhealthy to start with. And this includes some of the presenters. It takes time to change one’s health, relapses occur, and no one is getting younger. Moreover, some of the presenters’ ideas and advice may have much more dramatic positive effects on people other than themselves, because of their own pre-existing conditions. The ideas and advice are still solid.

A message that I think this Symposium conveyed particularly well was that an evolutionarily sound diet and lifestyle can truly revolutionize our health care system. Robb Wolf’s talk in particular, based on his recent experience in Nevada with law enforcement officers, made this point very effectively. The title of the talk is “How Markets and Evolution Can Revolutionize Medicine”. One very interesting idea he put forth was that establishments like gyms could expand the range of support activities they offer their customers, officially becoming the beginning of the health care chain. There are already health insurance plans that offer premium reductions for those who go to gyms. Being part of the health care chain would be different and a significant step forward - diet and exercise are powerful "drugs".

One thing that caught me a bit off-guard was Robb’s strong advocacy of the use of a drug, namely metformin (a.k.a. glucophage); even preventively in some special cases, such as with sleep-deprived law enforcement officers. I have to listen to that talk again when it is up online, to make sure that I understood it correctly. It seems to me that changing the nature of shift work among law enforcement officers, at least partially, may be a better target; current practices appear not only to impair the officers’ health but also their effectiveness in law enforcement activities. Besides, I think we need to better understand the nature and functions of cortisol, which is viewed by many as a hormone that exists only to do us harm.

Sleep deprivation is associated with an elevation in cortisol production. Elevated cortisol levels lead over time to visceral fat accumulation, which promotes systemic inflammation. Systemic inflammation is possibly the root cause of most diseases of civilization. But cortisol itself has powerful anti-inflammatory properties, and visceral fat is generally easy to mobilize through intense exercise – probably one of the key reasons why we have visceral fat. I think we need to understand this situation a bit better before thinking about preventive uses of metformin, which nevertheless is a drug that seems to do wonders in the treatment of type 2 diabetes.

Beth Mazur was kind enough to put up a post with links to various Ancestral Health Symposium 2012 summary posts, as well as pictures. Paul Jaminet has a post with an insightful discussion of our panel at the Symposium.

Strength training plus fasting regularly, and becoming diabetic!? No, it is just compensatory adaptation at work

One common outcome of doing glycogen-depleting exercise (e.g., strength training, sprinting) in combination with intermittent fasting is an increase in growth hormone (GH) levels. See this post for a graph showing the acute effect on GH levels of glycogen-depleting exercise. This effect applies to both men and women, and is generally healthy, leading to improvements in mood and many health markers.

It is a bit like GH therapy, with GH being “administered” to you by your own body. Both glycogen-depleting exercise and intermittent fasting increase GH levels; apparently they have an additive effect when done together.

Still, a complaint that one sees a lot from people who have been doing glycogen-depleting exercise and intermittent fasting for a while is that their fasting blood glucose levels go up. This is particularly true for obese folks (after they lose body fat), as obesity tends to be associated with low GH levels, although it is not restricted to the obese. In fact, many people decide to stop what they were doing because they think that they are becoming insulin resistant and on their way to developing type 2 diabetes. And, surely enough, when they stop, their blood glucose levels go down.

Guess what? If your blood glucose levels are going up quite a bit in response to glycogen-depleting exercise and intermittent fasting, maybe you are one of the lucky folks who are very effective at increasing their GH levels. The blood glucose increase effect is temporary, although it can last months, and is indeed caused by insulin resistance. An HbA1c test should also show an increase in hemoglobin glycation.

Over time, however, you will very likely become more insulin sensitive. What is happening is compensatory adaptation, with different short-term and long-term responses. In the short term, your body is trying to become a more efficient fat-burning machine, and GH is involved in this adaptation. But in the short term, GH leads to insulin resistance, probably via actions on muscle and fat cells. This gradually improves in the long term, possibly through a concomitant increase in liver insulin sensitivity and glycogen storage capacity.

This is somewhat similar to the response to GH therapy.

The figure below is from Johannsson et al. (1997). It shows what happened in terms of glucose metabolism when a group of obese men were administered recombinant GH for 9 months. The participants were aged 48–66, and were given in daily doses the equivalent to what would be needed to bring their GH levels to approximately what they were at age 20. For glucose, 5 mmol is about 90 mg, 5.5 is about 99, and 6 is about 108. GDR is glucose disposal rate; a measure of how quickly glucose is cleared from the blood.

As you can see, insulin sensitivity initially goes down for the GH group, and fasting blood glucose goes up quite a lot. But after 9 months the GH group has better insulin sensitivity. Their GDR is the same as in the placebo group, but with lower circulating insulin. The folks in the GH group also have significantly less body fat, and have better health markers, than those who took the placebo.

There is such a thing as sudden-onset type 2-like diabetes, but it is very rare (see Michael’s blog). Usually type 2 diabetes “telegraphs” its arrival through gradually increasing fasting blood glucose and HbA1c. However, those normally come together with other things, notably a decrease in HDL cholesterol and an increase in fasting triglycerides. Folks who do glycogen-depleting exercise and intermittent fasting tend to see the opposite – an increase in HDL cholesterol and a decrease in triglycerides.

So, if you are doing things that have the potential to increase your GH levels, a standard lipid panel can help you try to figure out whether insulin resistance is benign or not, if it happens.

By the way, GH and cortisol levels are correlated, which is often why some associate responses to glycogen-depleting exercise and intermittent fasting with esoteric nonsense that has no basis in scientific research like “adrenal fatigue”. Cortisol levels are meant to go up and down, but they should not go up and stay up while you are sitting down.

Avoid chronic stress, and keep on doing glycogen-depleting exercise and intermittent fasting; there is overwhelming scientific evidence that these things are good for you.

Cortisol, surprise-enhanced cognition, and flashbulb memories: Scaring people with a snake screen and getting a PhD for it!

Cortisol is a hormone that has a number of important functions. It gets us out of bed in the morning, it cranks up our metabolism in preparation for intense exercise, and it also helps us memorize things and even learn. Yes, it helps us learn. Memorization in particular, and cognition in general, would be significantly impaired without cortisol. When you are surprised, particularly with something unpleasant, cortisol levels increase and enhance cognition. This is in part what an interesting study suggests; a study in which I was involved. The study was properly “sanctified” by the academic peer-review process (Kock et al., 2009; full reference and link at the end of this post).

The main hypothesis tested through this study is also known as the “flashbulb memorization” hypothesis. Interestingly, up until this study was conducted no one seemed to have used evolution to provide a basis on which flashbulb memorization can be explained. The basic idea here is that enhanced cognition within the temporal vicinity of animal attacks (i.e., a few minutes before and after) allowed our hominid ancestors to better build and associate memories related to the animals and their typical habitat markers (e.g., vegetation, terrain, rock formations), which in turn increased their survival chances. Their survival chances increased because the memories helped them avoid a second encounter; if they survived the first, of course. And so flashbulb memorization evolved. (In fact, it might have evolved earlier than at the hominid stage, and it may also have evolved in other species.)

The study involved 186 student participants. The participants were asked to review web-based learning modules and subsequently take a test on what they had learned. Data from 6 learning modules in 2 experimental conditions were contrasted. In the treatment condition a web-based screen with a snake in attack position was used to surprise the participants; the snake screen was absent in the control condition. See schematic figure below (click on it to enlarge). The “surprise zone” in the figure comprises the modules immediately before and after the snake screen (modules 3 and 4); those are the modules in which higher scores were predicted.

The figure below (click on it to enlarge) shows a summary of the results. The top part of the figure shows the percentage differences between average scores obtained by participants in the treatment and control conditions. The bottom part of the figure shows the average scores obtained by participants in both conditions, as well as the scores that the participants would have obtained by chance. The chance scores would likely have been the ones obtained by the participants if their learning had been significantly impaired for any of the modules; this could have happened due to distraction, for example. As you can see, the scores for all modules are significantly higher than chance.

In summary, the participants who were surprised with the snake screen obtained significantly higher scores for the two modules immediately before (about 20 percent higher) and after (about 40 percent higher) the snake screen. The reason is that the surprise elicited by the snake screen increased cortisol levels, which in turn improved learning for modules 3 and 4. Adrenaline and noradrenaline (epinephrine and norepinephrine) may also be involved. This phenomenon is so odd that it seems to defy the laws of physics; note that Module 3 was reviewed before the snake screen. And, depending on the size of a test, this could have turned a “C” into an “A” grade!

Similarly, it is because of this action of cortisol that Americans reading this post, especially those who lived in the East Coast in 2001, remember vividly where they were, what they were doing, and who they were with, when they first heard about the September 11, 2001 Attacks. I was living in Philadelphia at the time, and I remember those details very vividly, even though the Attacks happened almost 10 years ago. That is one of the fascinating things that cortisol does; it instantaneously turns short-term contextual memories temporally associated with a surprise event (i.e., a few minutes before and after the event) into vivid long-term memories.

This study was part of the PhD research project of one of my former doctoral students, and now Dr. Ruth Chatelain-Jardon. Her PhD was granted in May 2010. She expanded the study through data collection in two different countries, and a wide range of analyses. (It is not that easy to get a PhD!) Her research provides solid evidence that flashbulb memorization is a real phenomenon, and also that it is a human universal. Thanks are also due to Dr. Jesus Carmona, another former doctoral student of mine who worked on a different PhD research project, but who also helped a lot with this project.

Reference:

Kock, N., Chatelain-Jardón, R., & Carmona, J. (2009). Scaring them into learning!? Using a snake screen to enhance the knowledge transfer effectiveness of a web interface. Decision Sciences Journal of Innovative Education, 7(2), 359-375.