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How Exercise Might Help Our Cells Help Us

The views expressed are those of the author and are not necessarily those of Scientific American.

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In addition to helping us get fit, exercise seems to play a disproportionate role in fending off chronic diseases, such as diabetes. A new study suggests how activity on the cellular level might be keeping us healthy when we get activity on the macro level.

The process in question is autophagy, a series of actions in which cells recycle internal bits and that, in turn, helps to keep cells agile and able to adjust to changes in energy requirements and nutritional conditions. Exercise kicks autophagy—in heart and skeletal muscles—into high gear in mice. And the new report, published online Wednesday in Nature, describes how this extra autophagy seems to help keep insulin resistance (a precursor to diabetes) at bay in the lab rodents (Scientific American is part of Nature Publishing Group).

The research team, led by Congcong He, of the University of Texas Southwestern Medical Center, compared mice that had been genetically engineered so that they did not get the autophagy boost to regular mice to see how each fared after exercise and a high-fat, diabetes-promoting diet. Mice without the natural levels of exercise-induced autophagy gained a little more weight on the high-fat diet and were slightly less active than their natural-bread counterparts. And perhaps more important, while the regular mice saw an improvement in their diet-related insulin resistance when they were exercised—making them less likely to get diabetes—the mutant mice who did not undergo the extra autophagy did not seem to get these exercise benefits.

“Our findings demonstrate that exercise is a potent inducer of autophagy,” the researchers wrote. “Autophagy induction may contribute to the beneficial metabolic effects of exercise,” they concluded.

The team also found that this cellular autophagy is controlled in part by a particular protein, BCL2, which other researchers have found plays a key role in cell death. Manipulating this protein “may be a logical strategy to mimic the health effects of exercise and to prevent or treat impaired glucose metabolism,” the researchers suggested.

Of course it would be a long way from these running lab mice to finding a related treatment for human diabetes, but the new find is just one of many recent clues scientists have gathered in an effort to better understand exercise and how its biochemical effects might help prevent metabolic diseases. Just last week, another team of researchers announced the discovery of irisin, a new exercise-induced hormone in humans and mice that seems to help burn extra calories and also improve insulin sensitivity.

Katherine Harmon Courage About the Author: Katherine Harmon Courage is a freelance writer and contributing editor for Scientific American. Her book Octopus! The Most Mysterious Creature In the Sea is out now from Penguin/Current. Follow on Twitter @KHCourage.

The views expressed are those of the author and are not necessarily those of Scientific American.

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  1. 1. Unksoldr 11:34 pm 01/18/2012

    Again, I must say WHY? Why take a man-made substitute that might improve your health. When it has be clearly demonstrated many times that simple exercise it much more effective and doesn’t have any unintended side effects. About 7 years ago I was diagnosed as insulin resistance/diabetic Type 2. I was of course put on 2 to 3 different meds to control it. I instead lost 20% of my body weight by changing my diet and exercising regularly. Now, the doctors still say I’m a diabetic but I take no meds and my A1c is normal.

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  2. 2. Unksoldr 11:35 pm 01/18/2012

    has been* clearly

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  3. 3. gearbuzz 5:43 am 01/19/2012

    @Unksoldr…At my early 60s I have seen nothing that corresponds to exercise in terms of rejuvenation. Nevertheless, people refuse to make an effort when they can take a pill. But aren’t we confusing ‘character’ with a medical (although I would argue the problem is one of free market irresponsibility) problem? And regarding your diabetes, or lack thereof, hang tough.

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  4. 4. ASHIK 10:34 am 01/19/2012

    Our targeted cells in body must be kept at a steady energy burning state to obtain best out of them.This can be done by regular exercises which warm up cells(cells which we use daily to overcome our challenges)to increase its potential to a steady state.

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  5. 5. FSM1987 10:41 am 01/19/2012

    Keep exercising, keep living!

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  6. 6. OnePumpChump 10:45 am 01/19/2012

    “Why make this thing? It won’t solve any problems for me, it must be useless!”

    There are lots of people who can’t get adequate exercise for a variety of reasons. Para/quadriplegics, MS sufferers, people with serious joint problems. For that matter, obesity itself can be a serious impediment to exercise, especially if it’s progressed to causing heart problems.

    But yeah, screw them, because personal responsibility.

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  7. 7. sidelight 2:50 pm 01/19/2012

    Proof that proper diet and exercise are the foundations of health and the fountain of youth. I decided not to turn 55 fat and out of shape, so I unloaded the fork losing 40 pounds, and began getting some daily exercise, mostly walking/running my dog, Maggie. Now, ( at 60) I run with her 3.7 miles 4-5 days a week and hit the gym for weight training 3-4 days a week. Next, I turn to very low fat high veggies and enough protein for an anti-cholesterol anti- inflammatory diet that is just what my grandmother told me to eat when I was a lad.

    Yes, all of modern science and medicine fails to prevent or cure any of the lifestyle diseases, but increasingly explains why Grandma was right. And, if you follow her advice, you have few diseases to treat or cure, and you can live young as you grow old.

    Throw in love, and you have it made.

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  8. 8. RobLewis 5:14 pm 01/20/2012

    Interesting, but I take issue with the characterization “high-fat, diabetes-promoting diet.” As researcher Robert Lustig has pointed out, it is an unconfirmed assumption that high-fat diets promote diabetes—the much more likely culprit is high carbohydrates, in particular the sugar fructose.

    My personal story is much like that of commenter Unksoldr above. I lost 30+ pounds on the Atkins diet and have continued to eat very few carbs and exercise religiously. I eat plenty of fat, but my glucose, blood lipids and blood pressure are great.

    New research out of Newcastle University in England has shown that in most cases Type 2 diabetes can be reversed with substantial, sustained weight loss.

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  9. 9. EMMag 7:15 pm 01/21/2012

    It sounds like this is the same pathway that an extremely reduced calore intake and/or dehydration can reduce chronic diseases by, the TOR (Target Of Rapamycin) receptor. It seems like a certain amount/ kinds of pressure actually help our bodies/cells police themselves.

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