Quick Carbs: Dark Side of Fructose (repost 2007)

A variety of conflicting studies and articles are coming out regarding high glycemic foods in performance. What impact do they have and what conflicting studies show is a future topic for us. Fructose is not considered an optimal source of carbs and the sports drinks and gels you use should be examined to make sure that fructose is not high on the ingredients list.

It is lower down on the listing of ingredients in Gatorade, but it is number 2, after water on Powerade (Matrix Reloaded). Powerade is said to be the official drink of the US Olympics. Perhaps it is time to revisit that choice.

At the same time this is under discussion Abel Pharmboy at Terrasig has a fine post up entitled “The Questionable Dark Side of Fructose“. He notes that the consumption of fructose has been suggested to be one of the possible causes of obesity and metabolic syndrome. In conjunction with this he links to an article at Medscape which notes the atherogenic profile of fructose vs. glucose. Continue reading Quick Carbs: Dark Side of Fructose (repost 2007)

Ralph Paffenbarger, M.D. Dies at Age 84 (repost from 2007)

Ralph Paffenbarger, was one of the first epidemiologists to study and provide evidence for the significance of exercise in lowering the risk of cardiovascular mortality (heart disease, etc.). His earliest studies showed that the risk of being sendentary (for example: sitting on your behind and playing computers games in todays parlance) was twice as great as exercising and burning up 2,000+ calories per week.

Ralph himself became a marathoner and ultra-marathoner.

His studies were significant and have had an enormous impact on health and understanding necessary components to living in a healthy manner. Between dietary changes, treatment of lipid and cholesterol abnormalities, blood pressure evaluation, and improvement in exercise routines, heart disease can be significantly reduced. The incidence of heart disease in the United States has decreased incredibly over the past 30 years.

Dr. Paffenbarger’s obituary may be viewed at the New York Times.

Achilles Tendinopathy: 2010 – Disappointing Results with PRP (repost from 01/2010)

Update: The results are still controversial and contradictory on PRP and Achilles tendinopathy. This is a repost of a blog from 2010. (The primary reason for the repost is moving material of archival interest to a site which functions better.)

A study published in the Journal of the American Medical Association, Jan. 13, 2010 gave disappointing results in using plasma rich protein to treat non-insertional Achilles tendinopathy. It showed no difference between using a sham injection of saline and combining it with a painful eccentric stretching protocol  in comparison with an injection of plasma rich protein injection along with the standard painful eccentric stretching protocol.

The authors note that previous studies did not have good control groups. In this small study, 27 patients were in the placebo group and 27 in the treatment group. The VISA-A score was used to assess improvement. Both groups improved somewhat without a significant difference between the two groups.

The study was called a “preliminary communication” which is often done with small studies. Other studies on similar topics with fewer than 30 individuals studies have also been billed as “preliminary studies”, but when they are talked up afterward, the “preliminary study” status is usually forgotten. As far as study design goes, the design, blinding, and performance of the study seems just right. I am not entirely convinced of the efficacy of the painful eccentric stretching protocol and would have not minded another study group omitting that treatment. Apparently it is not a panacea (or there would not be studies looking to add to the results), although the initial preliminary study made it sound as though it would be. Follow up journal articles by the primary author of the first study have been positive and are referenced below. Others have expressed reservations on the methodology. (see Woodley et. al. 2007 and Kingma et. al. 2006) Eccentric stretching and overload for tendinopathy has mixed results at best in other body areas.

Note: VISA-A is the Victorian Institute of Sports Assessment-Achilles


Platelet-Rich Plasma Injection for Chronic Achilles Tendinopathy: A Randomized Controlled Trial
Robert J. de Vos; Adam Weir; Hans T. M. van Schie; et al. JAMA. 2010;303(2):144-149 (doi:10.1001/jama.2009.1986)

Alfredson H. Chronic midportion Achilles tendinopathy: an update on research and treatment. Clin Sports Med. 2003;22(4):727-741.

Alfredson H and Cook J (2007), A treatment algorithm for managing Achilles tendinopathy, new treatment options, British Journal of Sports Medicine, 41, 4, 211.

J J Kingma, R de Knikker, H M Wittink, T Takken. Eccentric overload training in patients with chronic Achilles tendinopathy: a systematic review. Br J Sports Med 2007;41:e3 (http://www.bjsportmed.com/cgi/content/full/41/6/e3). doi: 10.1136/bjsm.2006.030916 (concludes: Studies on the effectiveness of eccentric overload training in patients with Achilles tendinopathy show many methodological shortcomings)

Woodley, B.L., R.J. Newsham- West, and D.B. Baxter, Chronic tendinopathy: effectiveness of eccentric exercise. Br J Sports Med, 2007. 41: p. 188-199.

Additional Information:

Pribut, S.M.,  Top 5 Running Injuries. Podiatry Management, 2008

Blog on: Heel Lifts and Achilles Tendinitis

Dr. Pribut on Achilles Tendinopathy

Dr. Pribut on The Science of Tendinopathy

Testosterone: Epitestosterone Ratio: Cheating or Genes?

(repost from 01/2011)

The Case Against Lance Armstrong” is the title of an article in the January 24, 2011 issue of Sports Illustrated. The case that is made within this article is based on in large part on what a few people with gripes against Lance have said. The other “hard” evidence is based on several tests detailing a very high Testosterone:Epitestosterone ratio. Before 2005 the tests normal was considered up to 6:1 and was then lowered to 4:1. Several tests over the years, which may have been Lance’s were considerably higher than this.

According to SI “Three results stand out: a 9.0-to-1 ratio from a sample collected on June 23, 1993; a 7.6-to-1 from July 7, 1994; and a 6.5-to-1 from June 4, 1996.”

Each time the ratio was found to be high, the “B” Sample was tested and found to not confirm the preliminary test. The second test is usually a carbon isotope test that is more specific to studying the makeup of the individual’s testosterone.

While the article goes on to say that one high number (of the T:E ratio) should be a once in a blue moon occurrence, there are significant genetic factors that can come into play.  A 2008 article published in The Journal of Clinical Endocrinology & Metabolism titled “Doping Test Results Dependent on Genotype of UGT2B17, the Major Enzyme for Testosterone Glucuronidationshowed that if an individual had two alleles for the UGT2B17 gene, there was a large chance that they would not test positive for cheating even after having taken a large dose of synthetic testosterone. The estimates were that 40% of individuals could pass the ratio examination just by virtue of having two copies of this gene. On the other hand with mixed alleles (ins/del) or in the absence of  this allele there was a fair chance that the ratio would always be abnormal. Estimates were that in a normal population, up to 9-14% of people would have a false positive result and fail the test.

It seems that if you have the del/del or ins/del variations of alleles, you are going to pretty consistently fail the test. The authors suggest that this gene should be tested and the results modified based upon the genotype of the individual.

Understanding the purpose of the Testosterone:Epitestosterone ratio testing and doing at least a brief look at  factors that might affect this test, not just once but repeatedly are important when an article such as the SI one is written. This specific gene and its implication on testing is widely known and has been covered in a variety of journal articles. The Canadian Medical Journal detailed, in an editorial titled “Doping, Sport, and the Community“, the difficulties in testing for Growth Hormone abuse and Testosterone. The editorial also mentioned research I came across elsewhere which indicated that many Asians (up to 40%) had the version of this gene that would give a false negative.

So, let’s get all the evidence out. And let’s make sure the public sees all the scientific information on the validity and the problems that exist with this particular test. For another perspective on heroes in American culture, you can seek out one of George Carlin’s last specials in which he expresses his opinion on hero worship and in particular on Lance Armstrong, Tiger Woods, and Dr. Phil.

The next test is to determine if the song “Bike” by Pink Floyd was written in a drug free state. In case you can’t make them out the lyrics begin:

I’ve got a bike
You can ride it if you like
It’s got a basket
A bell that rings
And things to make it look good
I’d give it to you if I could
But I borrowed it

Available video of Pink Floyd’s Bike (blocked currently at Youtube)

and if Pink Floyd is just not your cup of tea. Here is Queen performing their song “Bicycle Race”

Overuse Injuries: All The Small Things (repost 10/2010)

Podiatry Management (October, 2010) has just published an article I’ve written titled  Overuse Injuries: All The Small Things . You are just another click away from the PDF version. This is a challenging article. It introduces mechanotransduction, a theory of cellular and tissue function, which is little known in the sports medicine community. The article touches lightly on this topic and then reviews the latest literature and theory on overuse injuries to bone and tendon.

The Needle - Kenneth Snelson
The Needle - Kenneth Snelson

The cellular level is where things start and where we will find many answers. I expect to add more details on the web site on mechanotransduction and mechanobiology for those with hardcore, deep science interest. The article is limited in size, but was longer than many published in PM Magazine. But, I didn’t even touch on the theory canalicular flow and osteocyte induction or mechanotransduction and control of stem cell development by matrix stiffness. Research in the field of mechanobiology is growing daily and the outlook is great that it will be fruitful.