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Showing posts with the label cortisol

Could the low testosterone problem be a mirage?

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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 to...

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

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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 nonli...

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

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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 d...

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

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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 with...

Cortisol, stress, excessive gluconeogenesis, and visceral fat accumulation

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Cortisol is a hormone that plays several very important roles in the human body . Many of these are health-promoting, under the right circumstances. Others can be disease-promoting, especially if cortisol levels are chronically elevated. Among the disease-promoting effects of chronically elevated blood cortisol levels are that of excessive gluconeogenesis, causing high blood glucose levels even while a person is fasting. This also causes muscle wasting, as muscle tissue is used to elevate blood glucose levels. Cortisol also seems to transfer body fat from subcutaneous to visceral areas. Presumably cortisol promotes visceral fat accumulation to facilitate the mobilization of that fat in stressful “fight-or-flight” situations. Visceral fat is much easier to mobilize than subcutaneous fat, because visceral fat deposits are located in areas where vascularization is higher, and are closer to the portal vein. The problem is that modern humans often experience stress without the violent musc...

Cortisol response to stress is much more elevated with ingestion of glucose than with protein or fat

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Cortisol is a hormone that does a number of different things; a jack of all trades among hormones, so to speak. It tells the liver to produce glucose, preventing hypoglycemia. It also tells the liver to synthesize glycogen, which is in some ways the opposite of producing glucose. It tells the stomach to secret gastric acid. It is an anti-diuretic hormone. It suppresses the immune system, which is why it is frequently used to reduce inflammation, and treat allergies and various autoimmune diseases. It jump-starts an increase in free fatty acids in circulation, thus helping provide an important source of energy for endurance exercise. Cortisol, together with epinephrine (a.k.a. adrenaline), even contributes to the creation of surprise-induced memories. 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 th...

Growth hormone may rise 300 percent with exercise: Acute increases also occur in cortisol, adrenaline, and noradrenaline

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The figure below (click to enlarge) is from the outstanding book Physiology of sport and exercise , by Jack H. Wilmore, David L. Costill, and W. Larry Kenney. If you are serious about endurance or resistance exercise, or want to have a deeper understanding of exercise physiology beyond what one can get in popular exercise books, this book should be in your personal and/or institutional library. It is one of the most comprehensive textbooks on exercise physiology around. The full reference to the book is at the end of this post. The hormonal and free fatty acid responses shown on the two graphs are to relatively intense exercise combining aerobic and anaerobic components. Something like competitive cross-country running in an area with hills would lead to that type of response. As you can see, cortisol spikes at the beginning, combining forces with adrenaline and noradrenaline (a.k.a. epinephrine and norepinephrine) to quickly increase circulating free fatty acid levels. Then free fatty...

Niacin and its effects on growth hormone, glucagon, cortisol, blood lipids, mental disorders, and fasting glucose levels

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Niacin is a very interesting vitamin. It is also known as vitamin B 3 , or nicotinic acid. It is an essential vitamin whose deficiency leads to a dreadful disease known as pellagra . In large doses of 1 to 3 g per day it has several effects on blood lipids, including these: it increases HDL cholesterol, decreases triglycerides, and decreases Lp(a) . Given that this is essentially a reversal of the metabolic syndrome, for those who are on their way to developing it, niacin must really do something good for our body. Niacin is also a powerful antioxidant. The lipid modification effects of niacin are so consistent across a broad spectrum of the population that some companies that commercialize niacin-based products guarantee some measure of those effects. The graphs below (click to enlarge) are from Arizona Pharmaceuticals, a company that commercializes an instant-release niacin formulation called Nialor (see: arizonapharmaceuticals.com). The graphs show the peak effects on HDL cholestero...