The Burrill Report

There’s nothing I like better than a study that reinforces my lifestyle preferences, even if what the researchers are actually saying differs from my self-indulgent interpretation of their work. The latest piece of scholarship falling into this category comes from researchers at the Karolinska Institutet in Sweden, a highly respected and renowned institution I might add.

In the March issue of Cell Metabolism, the researchers report that when people who are healthy but inactive engage in exercise, it produces an immediate change to their DNA. What’s even more intriguing, and the part I particular enjoyed reading as I sat and drank the umpteenth cup of coffee that day, was that the scientists found the same changes occur when these folks consumed caffeine.
Now, the high-minded point here has to do with the often underappreciated dynamism of DNA, which, thanks to epigenetic modifications that turn genes on and back off again, allows DNA to be highly flexible and adjust to changing environments. These changes involve the gain or loss of chemical marks on DNA over and above the As, Gs, Ts, and Cs, that make up the DNA sequence. It also points to the plasticity of muscles.

The study found that the DNA within skeletal muscle taken from people after a burst of exercise bears fewer chemical marks—in this case so-called methyl groups—than it did before exercise. The changes take place in stretches of DNA involved in turning “on” genes important for muscles’ adaptation to exercise. The research says these particular changes appear to be early events in the genetic reprogramming of muscle for strength and, ultimately, in the structural and metabolic benefits of exercise.
When the researchers made muscles contract in lab dishes, they saw a similar loss of DNA methyl groups. Exposure of isolated muscle to caffeine had the same effect.
“Our muscles are really plastic,” says Juleen Zierath of Karolinska Institutet. “We often say ‘You are what you eat.’ Well, muscle adapts to what you do. If you don't use it, you lose it, and this is one of the mechanisms that allows that to happen.”

Zierath says that caffeine does mimic the muscle contraction that comes with exercise in other ways, too, but she doesn’t go so far as to recommend trading in your NordicTrack for a Mr. Coffee. What she does say is that the findings might point to a way medicines might be able to deliver similar benefit for people unable to exercise.
Nevertheless, when my wife goes out running this weekend, I think I’ll skip the usual constitutional with the dogs, fill their water bowl with a nice Italian Roast, and settle in with them on the couch. It’ll be a nice break from sitting at my desk all week.


March 09, 2012
http://www.burrillreport.com/article-working_out_at_starbucks.html