Research Blogging - Health - English

Nutrition and protein: training, performance and long-term health.

2012-05-25T20:18:03Z

These are interwoven issues. The aim of training is improve the body’s ability to perform certain tasks (and in the case of CrossFit it is to achieve a high degree of effectiveness and competence in a wide range of skills and efforts). The goal of nutrition in training is to help the body (the entire thing) adapt and remodel, or at least maintain what you have and can do. Bodies like efficiency. Your body will see no point in maintaining bone or muscle that does not look like it’s going to be used any time soon and will let it go. That’s why people who have been ill and disabled for a long time become so frail. When challenged your body (which means here not only muscle and bone, but brain, nerves, biochemical pathways and efficiency, cell proliferation and organelle numbers and function, and neurotransmitters) changes to meet that particular challenge. Protein is important here for repair, strengthen and reinforcement of stressed tissue. Strength-oriented athletes have traditionally made efforts to increase protein intake and there is some evidence that this is effective in increasing muscle mass. There is also evidence that increasing protein intake can reduce the rate of loss of muscle mass seen in aged people. Not all of the protein you can consume will be used to increase mass. Your body will use what it needs, or what it anticipates needing in the near future (in case you persist in doing all those squats, jerks, kettle bell swings and pushups.) Consuming a lot of protein will probably not hurt you. Not consuming enough will slow repair and limit your ability to adapt to physiological and mechanical stress. Endurance athletes have long been encouraged to eat plenty of carbohydrates since availability of carbs can be a limiting factor in performance. This is why consuming dilute fruit juice (or sugar water) can delay exhaustion and allow an athlete to continue to run, bike or whatever longer than they would if they had been drinking plain water. However if you are always running on carbohydrates you may not adapt biochemically speaking. Normally, if you are low on carbohydrates (or glycogen) your body will attempt to increase the rate at which is uses its own fat stores for energy. Being habitually low on carbs will increase your ability to generate energy by other means. You will probably be uncomfortable for at least a while, but you should improve at this the longer you train. So . . . while training, remember that you are training more than muscles. A lot of people involved with CrossFit advocate some interesting dietary approaches. It probably won't hurt you, and for a lot of people it will be better than what they were eating before. Keeping with the program helps people bond and gives them a sense of control. That can be very good, as long as it doesn't get too rigid or ridiculous. There are really too many unknowns floating around at present to know exactly what is best. What is best probably varies by individual, situation, stage of life, and training goals. New information becomes available. We'll see how things fall out. Churchward - Venne, T., Burd, N., Phillips, S., & Research Group, E. (2012). Nutritional regulation of muscle protein synthesis with resistance exercise: strategies to enhance anabolism Nutrition & Metabolism, 9 (1) DOI: 10.1186/1743-7075-9-40 Logan-Sprenger, H., Heigenhauser, G., Killian, K., & Spriet, L. (2012). The effects of dehydration during cycling on skeletal muscle metabolism in females Medicine & Science in Sports & Exercise DOI: 10.1249/MSS.0b013e31825abc7c Symonsi, T., Sheffield-Moore, M., Mamerow, M., Wolfe, R., & Paddon-Jones, D. (2010). The anabolic response to resistance exercise and a protein-rich meal is not diminished by age The journal of nutrition, health & aging, 15 (5), 376-381 DOI: 10.1007/s12603-010-0319-z...

Churchward - Venne, T., Burd, N., Phillips, S., & Research Group, E. (2012) Nutritional regulation of muscle protein synthesis with resistance exercise: strategies to enhance anabolism. Nutrition , 9(1), 40. DOI: 10.1186/1743-7075-9-40

Logan-Sprenger, H., Heigenhauser, G., Killian, K., & Spriet, L. (2012) The effects of dehydration during cycling on skeletal muscle metabolism in females. Medicine , 1. DOI: 10.1249/MSS.0b013e31825abc7c

Symonsi, T., Sheffield-Moore, M., Mamerow, M., Wolfe, R., & Paddon-Jones, D. (2010) The anabolic response to resistance exercise and a protein-rich meal is not diminished by age. The journal of nutrition, health , 15(5), 376-381. DOI: 10.1007/s12603-010-0319-z

Brain Connectivity Alterations in OCD

2012-05-25T11:51:41Z

Obsessive compulsive disorder (OCD) is an anxiety disorder characterized by intrusive thoughts interfering with everyday activities. The prevalence of OCD is estimated to be between 1 to 2 percent of the population. Despite several approved drug treatments and the availability of behavioral therapy, many individuals with OCD find their symptoms resistant to treatment. A better understanding of the underlying pathophysiology of OCD is needed for the development of more effective treatment.A recent brain imaging study provides some additional insight into the connectivity alterations found in those with OCD. In this study, 30 subjects with OCD were compared to a group of 32 control subjects using functional magnetic resonance imaging. The subjects were studied for functional connectivity of the default mode network (DFM) as well as the fronto-parietal network (FPN).The default mode network is the working network of brain regions typically active "at rest" when no specific brain-related task is being performed. You might think of this as what brain regions are in synchronization with each other during rest. We know that individuals with OCD commonly find their resting brain state is disrupted by their intrusive obsessional thoughts. This makes study of the default mode network promising for understanding OCD.The key findings in OCD from this study were:Reduction in the typical negative correlation between the DFM and the FPNAltered connectivity between the anterior insula and multiple DFM regions including the parahippocampus, medial frontal cortex, posterior cingulate cortex, and the posterior inferior parietal lobeIncreased connectivity of the FPN with regions outside the DFM including the thalamus, lateral frontal cortex and somatosensory/motor brain regionsThe authors note "Though speculative, the current findings of attenuated negative connectivity between anterior insula and DMN suggest a potential neural basis for the difficulty OCD patients may have in efforts to disengage from internal mental processes in order to respond to more appropriately salient external information related to potential risk (such as that informing them that dreaded events have not or will not occur)."The authors also note their study may not represent findings specific to OCD but may be related to broader anxiety conditions. This will need to be explored by contrasting differences (and similarities) across OCD with other anxiety disorders such as generalized anxiety disorder, panic disorder, social anxiety disorder and PTSD.This study is indicative of the evolving conceptualization of many mental disorders. Many mental disorders appear to not be due to a single neurotransmitter abnormality or a localized brain lesion but appear to be abnormalities of brain circuitry. Functional brain connectivity imaging of the DMN holds promise as a tool to better understand these circuitry alterations.Photo of female adult black bear from Lake Istasca State Park from the author's files.Stern, E., Fitzgerald, K., Welsh, R., Abelson, J., & Taylor, S. (2012). Resting-State Functional Connectivity between Fronto-Parietal and Default Mode Networks in Obsessive-Compulsive Disorder PLoS ONE, 7 (5) DOI: 10.1371/journal.pone.0036356...

Stern, E., Fitzgerald, K., Welsh, R., Abelson, J., & Taylor, S. (2012) Resting-State Functional Connectivity between Fronto-Parietal and Default Mode Networks in Obsessive-Compulsive Disorder. PLoS ONE, 7(5). DOI: 10.1371/journal.pone.0036356

Cochrane and a Significantly Biased Review of Steroids for acute spinal cord injury

2012-05-25T08:00:00Z

An interesting relic of trauma care is the use of steroids for the treatment of acute spinal cord injury. As with The Golden Hour, there are people still promoting this idea. In the words of Monty Python, it’s not quite dead, yet. Who is promoting this idea? The Cochrane Collaboration. Here is a list of the papers evaluated in this 2012 update of the 2009 Cochrane Review, which was an update of the 2002 Cochrane Review. There has been no change in the references, since the most recent paper reviewed is from 2000....

Bracken MB. (2012) Steroids for acute spinal cord injury. Cochrane database of systematic reviews (Online). PMID: 22258943

Ask Not What You Can Do For Educational Technology, But What Educational Technology Can Do For You

2012-05-25T00:46:54Z

It’s irritating that people talk about educational technology in terms of iPads in the classroom when the real impact will come from pinpoint differentiation, instant student assessment, and a third thing that nobody talks about – improved simulations in speciality learning. For example, medical students who use virtual patients — an “interactive computer simulation of real-life [...]...

Consorti, F., Mancuso, R., Nocioni, M., & Piccolo, A. (2012) Efficacy of virtual patients in medical education: A meta-analysis of randomized studies. Computers , 59(3), 1001-1008. DOI: 10.1016/j.compedu.2012.04.017

UK vs. US in Media Reporting on Eating Disorders: Who Does it Better?

2012-05-24T23:50:19Z

Given the popularity of my post on how the media portrays eating disorders, I thought I’d do a follow-up post about a more recent and comprehensive study on media reporting of eating disorders. Shepherd & Seale (2010) wanted to build up on the findings of O’Hara & Clegg-Smith, but focusing on UK newspapers. In particular, they: compared UK and US media reporting of EDs tracked changes of in ED coverage over a 17-year period studied the differences between newspapers with different target audiences Shepherd & Seale reiterate much of what O’Hara & Clegg-Smith wrote: ED specialists and researchers understand that EDs are complex, multi-factorial diseases with complex genetic and environmental underpinnings, that they are often associated with many medical complications …...

Shepherd, E., & Seale, C. (2010) Eating disorders in the media: The changing nature of UK newspaper reports. European Eating Disorders Review, 18(6), 486-495. DOI: 10.1002/erv.1006

Validation of the Dime

2012-05-24T14:35:00Z

The current Annals of Emergency Medicine has a pair of editorials on the article I wrote about[1] in This is the Way to Bad Medicine back in January. Dr. Radecki also was critical of this paper.[2] There is another study that refers to the same question published in this issue, but I will write about that paper later. "These data raise the real question, Do such findings matter? By admitting more patients and ordering more CTs, do we improve outcomes? Or do we simply find more things that have little clinical importance? Indeed, in Menditto’s sample,8 only 1 patient needed craniotomy. In Kaen’s,14 none did.[3]"...

Menditto, V., Lucci, M., Polonara, S., Pomponio, G., & Gabrielli, A. (2012) Management of Minor Head Injury in Patients Receiving Oral Anticoagulant Therapy: A Prospective Study of a 24-Hour Observation Protocol. Annals of Emergency Medicine. DOI: 10.1016/j.annemergmed.2011.12.003

The Death Of Good Cholesterol

2012-05-24T01:58:07Z

Briefly There were always two types of cholesterol, the good and the bad. Until now. A large new study tells us that good cholesterol might have been an impostor. That's food for the media types. For those who think before they type, the real news is that we are finally getting closer to uncovering the impostors. Thanks to the genetics revolution which seems to be paying off in an unexpected area. HDL - The Knight in Shining Armor In the cholesterol universe there are two camps: good cholesterol, also known as HDL, and bad cholesterol, often referred to as non-HDL cholesterol. The latter comes in a variety of flavors, of which LDL is the most prominent and best known. From many large observational studies we know that high levels of LDL and low levels of HDL associate with an elevated risk for heart disease and stroke. Certain limits have been derived from these studies, above which your LDL shouldn't rise and below which your HDL shouldn't fall. The magic level for HDL is 60 mg/dL blood. Above that limit, we are assured, HDL will even offset some other risk factor, such as age or being of the male persuasion. Given that a large percentage of people fail to achieve these desirable levels, researchers have been eagerly sourcing for pharmaceutical means to increase HDL. Now a new study tells us, that HDL might have to be stripped off its White-Knight title, much for the same reason as "Dr." Karl-Theodor zu Guttenberg, the former German defense minister, had to be stripped off his doctorate last year: for being an impostor. Epidemiology 101 If you have been following biomedical research for a couple of years, you will have noticed that results are often conflicting. So, you might discount the findings of one study if hundreds of others come to a different conclusion. Only in this case you should pay closer attention, because what Voight and colleagues have produced strikes at the foundation of how we do research in epidemiology, the science which studies the health of populations [1]. To appreciate the gravity of the situation, I need to familiarize you with a basic concept of epidemiological studies: Confounding. I'll use a very simple and hypothetical example. Let's say we are interested to know the causes of health and disease in children in the hypothetical and impoverished state of Maladipore. The figure to the left represents our astonishing finding that children growing up in a household which owns a TV are significantly less likely to die during childhood than children growing up without the boob tube. The correlation between TV ownership status and survival are very strong and compelling. On the face of it we could now recommend the prime minister to improve the health of the nation by simply installing a TV in every household in which there are children. If we know that this is nonsense, we take our epidemiology tools and look for another factor which has an influence on TV ownership AND on survival rate. And so we discover that wealth is this third factor. We call it a confounder. Wealth has confounded our original finding because the wealthy can afford a TV and they can also afford medical care and immunization for their children. Whereas the inability to buy a TV certainly reflects the inability to buy medical care, too. When we repeat our analysis of the data, which we gathered during our observational study, we find that the link between TV ownership and survival disappears once we bring the third variable, wealth, into the equation. Clearly, providing every household with a TV wouldn't have reduced the rate of child deaths. Greater wealth however will. In the case of Maladipore, common sense is all it takes to suspect and find the confounder. In real life it is almost never as simple. When we find an association between cholesterol and heart disease, then we typically have some idea about the way cholesterol might contribute to heart disease. At that stage our ideas are merely hypothetical. The classic way of investigating them is through clinical trials in which we randomize participants into 2 groups, one in which we lower (bad) cholesterol and another in which we don't, the control group. Then we observe them for a period and note the rate at which people in both groups develop heart disease or die from it. If we find that the control group, the one which didn't receive the benefit of having its cholesterol lowered, has a significantly higher rate of falling ill, we conclude that lowering cholesterol is the way to go. Sounds easy, but it isn't. For several reasons. In the case of cholesterol, the time between developing high bad, or low good, cholesterol and suffering a heart attack or stroke is measured in decades rather than in years. We also cannot just experiment with people as we would like to in the name of science. Ethics boards look very closely at the potential risks and benefits associated with what we do in trials. We cannot simply withhold treatment from a control group, with scientific curiosity as the motivation. With these obstacles, we had to draw our conclusions from observational studies, which tell us a lot about associations but nothing about cause and effect. Until now, we simply had no other choice. But not any more: It's Mendel All Over Again With larger and larger databases being developed from genetic research we can now do something else: Mendelian randomization studies. Which is what Voight and colleagues did. The concept behind it is amazingly simple and elegant, though not as brand new as you might think. It has been named after Gregor Mendel, the father of modern genetics, who first observed and described how traits are inherited. As always, a concept is best understood using an example. In the 1980s some researchers thought that very low cholesterol levels might increase the risk of cancer. There was definitely an association being observed between cancer and low cholesterol, but nobody knew which was the cause and which the effect. Or whether there was a third confounding variable, as yet unknown. Now, you can't make a study in which you lower the cholesterol in some people, just to see whether they will develop cancer. Go and find volunteers for that one....

Voight, B., Peloso, G., Orho-Melander, M., Frikke-Schmidt, R., Barbalic, M., Jensen, M., Hindy, G., Hólm, H., Ding, E., Johnson, T.... (2012) Plasma HDL cholesterol and risk of myocardial infarction: a mendelian randomisation study. The Lancet. DOI: 10.1016/S0140-6736(12)60312-2

Strength vs. Endurance and the Master Athlete.

2012-05-23T16:37:04Z

A Master and a very Junior Athlete. Masters Crossfitters, face a problem of having to work harder to build speed and strength, and maintain it, than do more junior athletes. There is unfortunately not a lot of research on Masters' performance and most of what there is focused on endurance athletes like swimmers, runners and cyclists. And little to go by when training as a Crossfit Master. As Crossfitters we need everything: speed, endurance and strength. As a general rule, all masters athletes can keep a competitive edge over peers by combining high-intensity aerobic and resistance training. This is exactly what we are getting in varied strength and endurance programming. Endurance athletes score high on cardiovascular markers with greater arterial flexibility, less thickening of arterial walls and better vascular endothelial performance (performance of the inner layers of blood vessels) than others. Unfortunately they show little preservation of muscle mass over time. Those who are primarily into resistance training maintain muscle mass and function better than others, but do not do as well on cardiovascular tests as those who focus on endurance. The best strategy appears to be to keep up with both and both will be important for Crossfit performance. That goes for juniors too. Shibata, S., & Levine, B. (2012). Effect of exercise training on biologic vascular age in healthy seniors AJP: Heart and Circulatory Physiology, 302 (6) DOI: 10.1152/ajpheart.00511.2011 Reaburn, P., & Dascombe, B. (2008). Anaerobic performance in masters athletes European Review of Aging and Physical Activity, 6 (1), 39-53 DOI: 10.1007/s11556-008-0041-6...

Shibata, S., & Levine, B. (2012) Effect of exercise training on biologic vascular age in healthy seniors. AJP: Heart and Circulatory Physiology, 302(6). DOI: 10.1152/ajpheart.00511.2011

Reaburn, P., & Dascombe, B. (2008) Anaerobic performance in masters athletes. European Review of Aging and Physical Activity, 6(1), 39-53. DOI: 10.1007/s11556-008-0041-6

Can Wii Fit #Exergame Help Elderly With Balance & Gait?

2012-05-23T15:37:02Z

The authors wanted to know if playing 3 Wii Fit games (50/50 Challenge, Ski Slalom and Soccer) would be comparable to a typical dynamic functional task, such as gait. They found that stability index... [[ This is a content summary only. Visit my website for full links, other content, and more! ]]...

Duclos C, Miéville C, Gagnon D, & Leclerc C. (2012) Dynamic stability requirements during gait and standing exergames on the wii fit(R) system in the elderly. Journal of neuroengineering and rehabilitation, 9(1), 28. PMID: 22607025

Video Tip of the Week: the New PubMed Filters Sidebar

2012-05-23T08:49:17Z

In today’s tip I am linking to a YouTube video from NCBI that briefly explains the new Filters Sidebar feature that has been added to PubMed. We first saw a tweet that the change was coming back on May 2nd, just as I was completing a total update to our full PubMed tutorial*. I struggled with [...]...

Sayers E. W., Barrett T., Benson D. A., Bolton E., Bryant S. H., Canese K., Chetvernin V., Church D. M., DiCuccio M., & Federhen S. (2011) Database resources of the National Center for Biotechnology Information. Nucleic Acids Research, 40(D1). DOI: 10.1093/nar/gkr1184