Wednesday, July 14, 2010

Dis ease - the idea of diseases as the cause of what ails us

Wikipedia describes disease as follows:

disease is an abnormal condition of the body of organism that is not comfortable for it. It is often construed to be a medical condition associated with specific symptoms andsigns.[1][2][3] It may be caused by external factors, such as infectious disease, or it may be caused by internal disfunctions, such as autoimmune diseases.
In humans, "disease" is often used more broadly to refer to any condition that causes paindysfunctiondistresssocial problems, and/or death to the person afflicted, or similar problems for those in contact with the person. In this broader sense, it sometimes includes injuriesdisabilitiesdisorderssyndromesinfections. Isolated symptoms, deviant behaviors, and atypical variations of structure and function, while in other contexts and for other purposes these may be considered distinguishable categories. A diseased body is quite often not only because of some dysfunction of a particular organ but can also be because of a state of mind of the affected person who is not at ease with a particular state of its body.

Our health care system is built upon the concept and the Merck Manual, a commonly used guide for diseases is used by doctors worldwide.  Disease is regularly used in languages throughout the world and in many cultures, since this is the way we are used to describing a series of symptoms, sometimes with a known cause of pathogen, or sometimes it is just a series of symptoms, named after someone that they described as a new disease or ailment that afflicts us, as well as most living things.  Disease has also been used by drug companies to sell product (eg: seasonal effective disorder, restless leg syndrome).  

In the chiropractic world, using this definition, back problems can be classified as diseases too, however, this is because it is dis  ease or as described above it is a medical condition of specific symptoms of signs.  The problem I have with this is that often, using the term disease describes an affliction, without promoting understanding.  Too often, diseases have been treated with medications to relieve the dis ease, without understanding why the problem exists.  Knee problems are a perfect example of this. We diagnosed meniscus disease, kneecap tracking disease which in no way describes what the condition is or how it got there.  We have trained people to treat these dis eases who could care less why it went bad.  The reason it went bad is the problem.  We teach them to throw therapies and solutions at the symptom which is knee pain which leads to tests and interventions, without the understanding of what we are treating. In the realm of musculoskeletal medicine, this is problematic, expensive, can be disabling (knee replacements gone bad with their thousands of dollars in implementation and rehab.  What the dis ease moniker does not do is promote understanding.  Lack of understanding currently leads to tests, questionable interventions and expensive solutions of limited benefit (knee replacements, which my mother had just undergone can last 10-15 years and then need to be redone). A better paradigm which is functionally based, rather than dis ease classified would lead to better prevention of many of the so called dis eases. Of course, there are many entities in our healthcare system who are profiting handsomely from the dis ease philosophy being used in the musculoskeletal system.  It has lead to unbelievable high costs of treatment, mediocre rehab based on a paradigm that is not meant to promote understanding , unneeded testing and human misery.  Managed care promised to hold the line on these costs but instead has tried to clear a profit without helping the paradigm change to a functionally correct one.  As they have failed, like the government, they simply pass the bill on to us as higher insurance premiums which has lead to more people underinsured with higher out of pocket costs and a health care system very far from cost effective and effective when compared to the rest of the world.

My recommendation is that at least in the musculoskeletal realm, we move away from the dis ease idea and move toward one of function, which will yield to lower costs from better care and more effective treatment and better preventative care.  Other diseases should come under the microscope too since we try to classify things we really do not understand into bite size pieces and then throw therapy regimens about the symptoms so the dis ease process is no longer noticed (not necessarily resolved).

Tuesday, July 13, 2010

Free running and primal workouts: Both look awesome, and dangerous

The other day I showed a YouTube MovNat video clip to one of my sons, noting the serious fitness of Erwan Le Corre. I also noted that the stunts were somewhat dangerous, and that they tried to replicate some of the movements that our Paleolithic ancestors had to do on a regular basis. That is, those movements are part of what one could call a primal workout.

My son looked at me and laughed, as if asking me if I was really being serious. Why? Well, he is into breakdancing (a.k.a. b-boying), and also does a bit of something called "free running". If you don’t know what free running is, take a look at this Wikipedia article.

Here are a couple of YouTube video clips on free running: clip 1, and clip 2. The moves do look a lot more hardcore than the ones on the MovNat video clip. (The reason for my son's reaction.) But, to be fair, the environments and goals are different. And, in terms of danger, some of these free running moves are really at the high end of the scale.

And, if you are interested, here are a couple of instructional YouTube video clips prepared by my sons: this one by my oldest, and this by my second oldest. (We have four children.) I have been telling them to be careful with those “airchairs” – the moves where all the weight is placed on one hand. It just looks like too much pressure on the joints of one single arm.

Two of the things that I like the most about primal workouts like the MovNat ones are the variety of movements, and the proximity to nature. Those two elements can potentially help with sticking to an exercise program in the long run, which is what matters most. Most people get very bored of exercising after a few months. Free running seems to be more competitive, and more dangerous.

Both free running and primal workouts are practiced by some people as their main form of exercise. In those cases, they appear to lead to body types that are similar to those of the hunter-gatherers on this post. I cannot help but notice that those body types are more like that of a sprinter than that of a typical bodybuilder.

The feats that those body types enable are feats of relative, not absolute, strength. This makes sense, as our Paleolithic ancestors were too smart to hunt prey or fight off predators (or even each other) with their bare hands. Spears and stones were formidable weapons. Paleolithic ancestors who were very adept at using weapons would probably be like skilled gunfighters in the American Old West – menacing, with the advantage of being able to use their skills to feed themselves and others.

Being lean, strong, and agile – all at the same time – arguably was one of the keys to survival in the Paleolithic.

Thursday, July 8, 2010

China Study Problems of Interpretation

The China study was an observational study that collected a massive amount of information about diet and health in 65 different rural regions of China. It's been popularized by Dr. T. Colin Campbell, who has argued that the study shows that plant foods are generally superior to animal foods for health, and even a small amount of animal food is harmful. Campbell's book has been at the center of the strict vegetarian (vegan) movement since its publication.

Richard from Free the Animal just passed on some information that many of you may find interesting. A woman named Denise Minger recently published a series of posts on the China study. She looked up the raw data and applied statistics to it. It's the most thorough review of the data I've seen so far. She raises some points about Campbell's interpretation of the data that are frankly disturbing. As I like to say, the problem is usually not in the data-- it's in the interpretation.

One of the things Minger points out is that wheat intake had a massive correlation with coronary heart disease-- one of the strongest correlations the investigators found. Is that because wheat causes CHD, or is it because wheat eating regions tend to be further North and thus have worse vitamin D status? I don't know, but it's an interesting observation nevertheless. Check out Denise Minger's posts... if you have the stamina:

The China Study: Fact or Fallacy

Also, see posts on the China study by Richard Nikoley, Chris Masterjohn and Anthony Colpo:

T. Colin Campbell's the China Study
The Truth About the China Study
The China Study: More Vegan Nonsense

And my previous post on the association between wheat intake and obesity in China:

Wheat in China

Our body’s priority is preventing hypoglycemia, not hyperglycemia

An adult human has about 5 l of blood in circulation. Considering a blood glucose concentration of 100 mg/dl, this translates into a total amount of glucose in the blood of about 5 g (5 l x 0.1 g / 0.1 l). That is approximately a teaspoon of glucose. If a person’s blood glucose goes down to about half of that, the person will enter a state of hypoglycemia. Severe and/or prolonged hypoglycemia can cause seizures, comma, and death.

In other words, the disappearance of about 2.5 g of glucose from the blood will lead to hypoglycemia. Since 2.5 g of glucose yields about 10 calories, it should be easy to see that it does not take much to make someone hypoglycemic in the absence of compensatory mechanisms. An adult will consume on average 6 to 9 times as many calories just sitting quietly, and a proportion of those calories will come from glucose.

While hypoglycemia has severe negative health effects in the short term, including the most severe of all - death, hyperglycemia has primarily long-term negative health effects. Given this, it is no surprise that our body’s priority is to prevent hypoglycemia, not hyperglycemia.

The figure below, from the outstanding book by Brooks and colleagues (2005), shows two graphs. The graph at the top shows the variation of arterial glucose in response to exercise. The graph at the bottom shows the variation of whole-body and muscle glucose uptake, plus hepatic glucose production, in response to exercise. The full reference to the Brooks and colleagues book is at the end of this post.


Note how blood glucose increases dramatically as the intensity of the exercise session increases, which means that muscle tissue consumption of glucose is also increasing. This is particularly noticeable as arm exercise is added to leg exercise, bringing the exercise intensity to 82 percent of maximal capacity. This blood glucose elevation is similar to the elevation one would normally see in response to all-out sprinting and weight training within the anaerobic range (with enough weight to allow only 6 to 12 repetitions, or a time under tension of about 30 to 70 seconds).

The dashed line at the bottom graph represents whole-body glucose uptake, including what would be necessary for the body to function in the absence of exercise. This is why whole-body glucose uptake is higher than muscle glucose uptake induced by exercise; the latter was measured through a glucose tracing method. The top of the error bars above the points on the dashed line represent hepatic glucose production, which is always ahead of whole-body glucose uptake. This is our body doing what it needs to do to prevent hypoglycemia.

One point that is important to make here is that at the beginning of an anaerobic exercise session muscle uses up primarily local glycogen stores (not liver glycogen stores), and can completely deplete them in a very localized fashion. Muscle glycogen stores add up to 500 g, but intense exercise depletes glycogen stores locally, only within the muscles being used. Still, muscle glycogen use generates lactate as a byproduct, which is then used by the liver to produce glucose (gluconeogenesis) to prevent hypoglycemia. The liver also makes some glycogen (glycogenesis) during this time. This means that it is not only pre-exercise liver glycogen that is being used to maintain blood glucose levels above whole-body glucose uptake. This makes sense, since the liver stores only about 100 g of glycogen.

The need to prevent hypoglycemia at all costs is the main reason why there are several hormones that increase blood glucose, while apparently there is only one that decreases blood glucose. Examples of hormones that increase blood glucose are cortisol, adrenaline, noradrenaline, growth hormone, and, notably, glucagon. The only hormone that decreases blood glucose levels in a significant way is insulin. These hormones do not increase or decrease blood glucose directly; they signal to various tissues to either secrete or absorb glucose.

Evolution typically prioritizes processes that have a higher impact on reproductive success, and one must be alive to successfully reproduce. Hypoglycemia causes death. Often those processes that have a significant effect on reproductive success rely on redundant mechanisms. So our evolved mechanisms to deal with hypoglycemia are redundant. Evolution is not an engineer; it is a tinkerer!

What about hyperglycemia – doesn’t it cause death? Well, not in the short term, so related selection pressures were fairly small compared to those associated with hypoglycemia. Besides, there were no foods rich in refined carbohydrates and sugars in the Paleolithic - e.g., white bread, bagels, doughnuts, pasta, cereals, fruit juices, regular sodas, table sugar. Those are the foods that contribute the most to hyperglycemia.

Reference:

Brooks, G.A., Fahey, T.D., & Baldwin, K.M. (2005). Exercise physiology: Human bioenergetics and its applications. Boston, MA: McGraw-Hill.