Regular Exercise Shown To Help Clean Out Cells

There are of course many reasons to exercise on a regular basis, but according to a new study by the University of Texas Southwestern Medical Center and published in the interdisciplinary, peer-reviewed science journal Nature, physical activity can help individual cells speed up their flushing out of garbage – cleaning their houses, for all intents and purposes.

Cellular "Garbage"

Scientists have long been aware that due to the simple stresses of regular living, cells tend to fill with such bits of debris like pieces of membrane, misshapen or otherwise useless proteins, bacterium or harmful viruses, and broken or otherwise past-their-prime cellular bits such as old mitochondria – all of which can result in a sort of rubbish pile inside the cell, one in need of being disposed of.

And more often than not, the cell does take care of such housekeeping, even going so far to use the rubbish as a source of fuel via the process of “autophagy” – essentially, self-eating – wherein a particular kind of membrane is created that traps the rubbish within the cytoplasm of the cell, and the rubbish is then disassembled and burned for energy by the cell’s lysosome.

Were it not for this process, the abundance of rubbish would likely cause cells to break down and die.  Indeed, many scientists have theorized that a wide range of maladies such as cancer, diabetes, Alzheimer’s, and muscular dystrophy may be at least partially caused by malfunctioning autophagy.  It is also suspected that the tendency of the autophagy process to slow after a few decades is a major factor in why we age.

Research into the metabolism has suggested that autophagy is an evolutionary response to the threat of starvation, in that in order to stay alive, cells would essentially cannibalize otherwise unneeded pieces of themselves.  Autophagy accelerates in laboratory settings when test cells are denied sustenance or are otherwise stressed out physiologically.

Exercise And Physiological Stress

It didn’t occur to researchers until fairly recently to look into whether the physiological stress that comes with exercise could have such an impact on autophagy, and if it did, if it would have any kind of appreciable impact on the entire body.

So, the Dallas-based team set to find out using two sets of mice – one group which had been selectively bred to have an inefficient autophagy, and another group with regular, well-operating systems.   The mice with poor autophagy had been given a substance that caused their rubbish-engulfing membranes to glow and thus be easily recognizable, and after being made to run for half an hour, the number of glowing membranes increased considerably, thus signaling that their autophagy was accelerated.

To find out what this increased autophagy meant for the overall health of the mice – if anything – they then bred a new generation of mouse that displayed regular levels of autophagy under normal circumstances, but which was unable to increase it, even when excessively exercised or denied food.  When these mice were run in comparison to the normal mice, they (the specialized mice) reached fatigue much faster, and their muscles appeared to be unable to draw on their blood sugar for energy.

Both sets of mice were also given high-fat food for a few months without being able to exercise until diabetes set in, and after they were finally allowed to start exercising again, the regular mice were able to reverse the diabetes through the exercise, while the mice with suppressed autophagy not only remained diabetic, their cholesterol levels grew.

This lead the team to conclude that the increased autophagy brought on by exercise is an important component in gaining the health advantages of exercise.