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Scientists Discover That Exercise Changes Your DNA
HughPickens.com writes The human genome is astonishingly complex and dynamic, with genes constantly turning on or off, depending on what biochemical signals they receive from the body. Scientists have known that certain genes become active or quieter as a result of exercise but they hadn't understood how those genes knew how to respond to exercise. Now the NYT reports that scientists at the Karolinska Institute in Stockholm have completed a study where they recruited 23 young and healthy men and women, brought them to the lab for a series of physical performance and medical tests, including a muscle biopsy, and then asked them to exercise half of their lower bodies for three months. The volunteers pedaled one-legged at a moderate pace for 45 minutes, four times per week for three months. Then the scientists repeated the muscle biopsies and other tests with each volunteer. Not surprisingly, the volunteers' exercised leg was more powerful now than the other, showing that the exercise had resulted in physical improvements. But there were also changes within the exercised muscle cells' DNA. Using technology that analyses 480,000 positions throughout the genome, they could see that new methylation patterns had taken place in 7,000 genes (an individual has 20–25,000 genes).
In a process known as DNA methylation, clusters of atoms, called methyl groups, attach to the outside of a gene like microscopic mollusks and make the gene more or less able to receive and respond to biochemical signals from the body. In the exercised portions of the bodies, many of the methylation changes were on portions of the genome known as enhancers that can amplify the expression of proteins by genes. And gene expression was noticeably increased or changed in thousands of the muscle-cell genes that the researchers studied. Most of the genes in question are known to play a role in energy metabolism, insulin response and inflammation within muscles. In other words, they affect how healthy and fit our muscles — and bodies — become. Many mysteries still remain but the message of the study is unambiguous. "Through endurance training — a lifestyle change that is easily available for most people and doesn't cost much money," says Sara Lindholm, "we can induce changes that affect how we use our genes and, through that, get healthier and more functional muscles that ultimately improve our quality of life."
In a process known as DNA methylation, clusters of atoms, called methyl groups, attach to the outside of a gene like microscopic mollusks and make the gene more or less able to receive and respond to biochemical signals from the body. In the exercised portions of the bodies, many of the methylation changes were on portions of the genome known as enhancers that can amplify the expression of proteins by genes. And gene expression was noticeably increased or changed in thousands of the muscle-cell genes that the researchers studied. Most of the genes in question are known to play a role in energy metabolism, insulin response and inflammation within muscles. In other words, they affect how healthy and fit our muscles — and bodies — become. Many mysteries still remain but the message of the study is unambiguous. "Through endurance training — a lifestyle change that is easily available for most people and doesn't cost much money," says Sara Lindholm, "we can induce changes that affect how we use our genes and, through that, get healthier and more functional muscles that ultimately improve our quality of life."
Meh, the summary doesn't bring up any of the new stuff.
We *know* that exercise has an effect on the body. We *know* that exercising increases concentrations of growth hormones, anti-inflammatory responses, and metabolic rate adjusting factors. We *know* these adjustments are made through methylation patterns over enhancers/promoters.
Furthermore, there is no *change* in the DNA. Any alterations that occur do so on the back-chain of the DNA, which is normal behavior as the backchain is modified by ALOT of different factors. No nucleotides are being mutated or swapped by exercising (unless you imbibe strange and unhealthy body building substances).
Last, the adjustments made to the exercised cells are in *response* to the exercise rather than proactive as the summary suggests. It would after all be really freaky if your body started building up muscles *before* you started working out. That would actually freak me the hell out.
Almost everything you do has an effect on DNA histone methylation, acetylation and other histone modifications. In order for the transcriptional complexes required for gene activation and transcription to gain access to DNA segments for copying (making messenger RNA) the histone complexes that protect DNA from damage must be opened up. So exercise, hormones, fasting, and even drinking alcohol will result in epigenetic DNA histone modifications associated with gene transcription. This has been known for many years now. It is not even slightly surprising that exercise would result in gene transcription, which requires histone modification. This is not "changing your DNA", it is modifying the proteins that protect DNA from damage (histones).
A brain is a terrible thing to waste... Mind? That's debatable.
True, this isn't particularly earth shattering, but you are incorrect in stating that there is no change in DNA. Methylation covalently (stably) alters DNA. So it actually does create a different nucleotide, one that is recognized by the cell as different from the original. This COULD result in germ cell (ie, heritable) changes.
There is absolutely no data to suggest that this particular set of methylation events has anything to do with reproduction or reproductive fitness, but mechanistically, it's possible. We are still pretty much working out the importance and scope of DNA methylation. In this particular instance, it is not at all clear that it does anything except alter gene expression - and we know that exercise causes gene expression changes. Those new biceps didn't just magically pop into being (unless you are photoshopped).
Faster! Faster! Faster would be better!