Sunday, August 05, 2012

Dr. Greg Wells Writes about Athletes and Telomeres

Dr. Greg Wells is a professor in the Faculty of Kinesiology and Physical Education at the University of Toronto. He's the author of Superbodies and he's one of the people commenting on biochemistry on Olympic broadcasts in Canada (see Muscles and the Lactic Acid Myth). It's somewhat unusual to promote yourself as "Dr. Wells" with a Ph.D. in physiology but that's his right.

Here's what he says on his blog,
Greg Wells, Ph.D. is a scientist and physiologist who specializes in health and performance in extreme conditions. Most recently, Dr. Wells was the host of the Gemini-Award winning “Superbodies” segments for Canada’s national Olympic broadcast and the on-camera sport science and sport medicine analyst for the CTV Broadcast Consortium, ABC News and ABC’s 20/20 during the 2010 Vancouver Olympics. Dr. Wells’ on-camera analysis will be a part of CTV’s 2012 Olympic broadcast in London.
Here's one of the "Superbodies" clips that are being shown on Canadian television. Most of them are quite interesting and informative even if Greg Wells does talk about lactic acid from time to time.

I was checking out his blog and found this interesting article: Olympic Science Blog: The science of exercise and ageing.
It is well established that training helps to improve pretty much every organ system in the body including the muscles, blood, brain, nervous system, skin, heart among others. Check out the book "Spark" to read about how exercise can help the brain! But new research shows that exercise can protect our genes as well!

In a recent study, researchers examined the DNA of young and old athletes and healthy control non-smokers for a total of four study groups. As expected, the researchers were able to demonstrate that the athletes had a slower resting heart rate, lower blood pressure and body mass index, and a more favorable cholesterol profile. But the surprising finding was that the rate of accumulated damage to the DNA was much less in the older athletes (average age: 51) than the older healthy non-athletes. In fact, the DNA of the older athletes was “younger” than the younger non-athlete participants. Researchers measured the ends of the chromosomes that contain our DNA. The ends of the chromosomes are called telomeres, and can be thought of as being similar to the caps on the end of your shoelaces (they’re called aglets in case you’re wondering) that prevent the laces from fraying. The scientists who discovered telomeres and how they work won the Nobel Prize in Physiology and Medicine in 2009. Telomeres control the number of times that a chromosome can divide when replicating itself as happens through our lifetime. Cells naturally grow, divide to replicate themselves and then die off. Gradually through this replication process, telomeres shorten and when they become “critically short” the cell dies. On the whole body level this may lead to ageing and a shortened lifespan. Scientists have shown that exercise activates an enzyme called telomerase that protects telomeres and chromosomes and that this has an anti-ageing effect, especially on the cardiovascular system.

World class athletes are training smarter, eating better, and recovering more effectively than ever before. The combination of these factors is helping athletes to have longer and more successful careers. So while you're watching our athletes compete in London and marveling at their performances, think about getting out and doing some exercise yourself! You'll be helping your body - right down to your DNA!
There's a lot wrong with this claim. First, it's not clear that there's a cause-and-effect relationship between telomore length and aging in spite of what some people claim. In fact, the correlation between age and telomere length is barely significant in most studies.

Second, it seems very unlikely that Lamarck was correct and it seems very unlikely that exercise has an effect on expression of the gene for telomerase.

Third, do you suppose it could be possible that when you get older and your health deteriorates for various reasons (disease, aging, accident) you tend not to continue to be an athlete? Thus, the only old athletes you measure are those that are still in good health?

Fourth, what's the evidence that telomere length has more of an effect on the cardiovascular system than on other parts of your body?


10 comments :

  1. Why is it "somewhat unusual to promote yourself as 'Dr. Wells' with a Ph.D. in physiology"?

    Don't Ph.D.s in all disciplines mean the recipients can call themselves doctor?

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    1. If you have a Ph.D. in any discipline you can call yourself "Doctor." Most people with Ph.D.s don't. That's why you don't normally refer to Dr. Carl Sagen, Dr. David Suzuki, Dr. Richard Dawkins, Dr. PZ Myers, Dr. Phil Plait, Dr. Stephen Jay Gould, Dr. Jonathan Wells, Dr. Isaac Asimov, Dr. Michael Ruse, Dr. Francis Crick, Dr. James Watson etc. etc.

      If you have an M.D. degree it's a different story. That degree is an undergraduate degree that's easily trumped by a Ph.D. but it's become standard practice for physicians to always refer to themselves as "Dr." Dr. Sanjay Gupta is a good example. It's a mark of status in society, that's why "Dr." has been appropriated by chiropractors.

      As far as the general public is concerned, when someone identifies themselves as "doctor" outside of academic circles, it means medical doctor. In a situation where you're talking about health and human fitness, identifying yourself as Dr. means medical doctor whether you intend it or not.

      If one really need to promote one's status while avoiding confusion one can refer to themselves as "Professor," provided they really are a professor.

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    2. I think the word "Professor" positively exudes pomposity, hubris and condescension. "Reader", or "Fellow", are more humane.

      Delete
  2. Generally, in Canada and the US, only medical doctors use the prefix "Dr.". Others tend to use Mr. or Ms with ", PhD" as a suffix to their names.

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  3. It is interesting that Larry brings up the subject of telomeres. This because more and more papers are revealing how retrotransposons (the vast majority of which Larry regards as "junk") contribute to telomere functionality and robustness:

    Retrotransposons provide an evolutionarily robust non-telomerase mechanism to maintain telomeres.(2003). Pardue and DeBaryshe

    http://www.ncbi.nlm.nih.gov/pubmed/14616071

    Of course, Larry regards evidence like this as just being a needle in a haystack - a rare instance of the evolutionary co-option of junk. Thankfully, most researchers are not put off by his indifference and insouciance (I see it as intransigence).

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    1. Missed the point, yet again 'clast.

      In your specific example, Drosophila lost the telomerase genes, and the retrotransposons have assumed the old function of adding the chromosome ends. They are not widely used in other Orders, as you are implying.

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  4. If you have an M.D. degree it's a different story. That degree is an undergraduate degree that's easily trumped by a Ph.D. but it's become standard practice for physicians to always refer to themselves as "Dr." Dr. Sanjay Gupta is a good example. It's a mark of status in society, that's why "Dr." has been appropriated by chiropractors.
    ********************************************************
    In the US, M.D. (doctor of medicine) is not considered an undergraduate degree. It is a post-bachelor's professional degree. Looking at admission rates of top medical schools vs. top graduate schools, I would say medical schools in the US are far more competitive to get into than graduate schools. I have seen mediocre students (in both the laboratory and classroom) get into Ph.D. programs. Those students would never get into an accredited US medical school unless they did post-bac work that should they had significant improvement over their undergraduate performance.

    Many of those with Ph.D.s (doctors of philosophy) in the US do use Dr. when being formal in place of "Mr. or Ms.". Do we really need to denote our gender? Many companies assume lab members do have Ph.D.s and address shipments to Dr. So-So. My Ph.D. mentor advised us to address those with Ph.D.s as Dr. Last Name or if appropriate Professor Last Name until corrected by the person being addressed.

    Typically though, we are informal and go by our first name when interacting with people.

    When we write out our name for business cards or in the signature of e-mails it is typical "First Name Last Name, Ph.D.". "Mr. or Ms. First and Last Name, Ph.D." is rare and looks weird to my eyes. I have seen many medical doctors use the First and Last Name, M.D. on their business cards.

    I have seen chiropractors use Dr. First and Last Name, D.C., which is just absurd.

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    Replies
    1. The M.D. degree is definitely a professional degree. In many countries you don't need a bachelor's degree in order to get into medical school and the equivalent degree for practicing medicine is called something different.

      At my university you are allowed to train Ph.D. graduate students even if you only have an M.D. degree. That's absurd and should be stopped.

      See Doctor of Medicine for more details.

      It's true that many who get into Ph.D. programs don't have as high a GPA as those who get into medical school. But it's also true that many who get into medical schools don't have the qualifications, research experience, and letters of recommendation required to get into graduate school.

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    2. The point is in the US, an MD is not considered an undergraduate degree. It is an advanced degree.

      In the US where an MD is an advanced degree, should they be able to train Ph.D. students? What if they have post-doctoral training? Tom Pollard has an MD and is considered by many to be tops in his field of research on myosin, actin and motility. He is a winner of the Gairdner.

      Most of the students we send to medical school do have extensive research experience and would get strong letters. In fact many of them are better researchers than a number of students who do get into Ph.D. programs. It amazes some of us faculty that tepid letters with mediocre grades do not prevent students from getting into graduate programs. Tepid letters to medical schools usually result in rejections for applicants. I think too many graduate programs want an extra pair of hands at a cheap price as they accept students who will do as they are told without much thought. Not exactly the type of person who should get a Ph.D. in my opinion but others evidently disagree.

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    3. In fact many of them are better researchers than a number of students who do get into Ph.D. programs.

      Please provide evidence for this claim. Or please define what you mean by "many". I work in a field where MDs and PhDs interact a lot. We each have our strengths, but the MDs strength tends to not be their research...

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