Exercise Alters DNA within minutes

How Exercise Can Change Your DNA
By Alice Park
Time
March 07, 2012

Just 20 Minutes of Exercise Can Change Your Genes MyHealthNewsDaily

Exercise does a lot of good things — it burns calories, helps keep your weight in check and lowers your risk of heart disease, stroke and diabetes. Now add one more thing to the list: physical activity can change your DNA.

Unlike the aberrations and genetic mutations caused by carcinogens and toxins, exercise-induced alterations to DNA are more like tune-ups, helping muscles to work better and more efficiently. What’s more, these changes occur even after a single 20-minute workout.

Juleen Zierath, a professor of physiology at the Karolinska Institute in Stockholm, reports with her colleagues in the journal Cell Metabolism about these very early changes that muscle cells undergo the first time you get off the couch and into the gym. The researchers worked with a group of 14 young men and women who were relatively sedentary, and asked them to work out on an exercise bike that measured their maximum activity levels. The participants also volunteered to give up a little bit of muscle, from their quadriceps, in a relatively painless biopsy procedure performed under local anesthesia. The researchers took the biopsy of muscle cells once before the participants exercised, and again within 20 minutes afterward.

VIDEO: Walking While Working: Healthland’s Belinda Luscombe Tries the Treadmill Desk

Using the biopsied samples, researchers compared the activity in a series of muscle-related genes before and after exercise. More genes were turned on in the cells taken after the exercise and the participants’ DNA showed less methylation, a molecular process in which chemicals called methyl groups settle on the DNA and limit the cell’s ability to access, or switch on, certain genes. By controlling how much methylation goes on in certain cells at specific times, the body regulates which genes in the DNA are activated — that’s what differentiates the development of an an eye cell, for example, from that of a liver cell.

Methylation also helps to prime muscle cells for a bout of exercise, getting them to pump out the right enzymes and nutrients the muscle needs to get energy and burn calories while you’re pounding the pavement during that mile-long jog. “We are trying to get at the early messages that the muscle is [receiving in order] to say, ‘Something is happening here, we need to coordinate so we can get more enzymes and more machinery on board so we can cope with the demands of this exercise,’” says Zierath.

The more intense the exercise, she says, the more the methyl groups are on the move. She and her team were able to see this firsthand by comparing gene activity in participants who also agreed to exercise at two different intensities over a period of a week. On one visit, they were asked to cycle until they reached 40% of their maximum capacity; on another occasion, they biked until they reached 80% of their maximum. The muscle biopsies following the 80% sessions showed a lower concentration of methyl groups — and therefore more RNA, which is the first byproduct of gene activity — than samples taken after the 40% sessions.

MORE: Why Exercise Won’t Make You Thin

To confirm the role of exercise on gene expression in muscle, the scientists then studied how calcium affected the entire system. When muscle cells start to gear up for intense activity like exercise, they release calcium, which fuels the contraction process. When the scientists blocked calcium production, the effect disappeared, and the muscles didn’t contract as much.

That’s when Zierath threw in some coffee — or more specifically, caffeine. Caffeine triggers the release of calcium, and can enhance the way methyl groups move aside to turn on the genes that help muscles contract. When she added caffeine to a lab dish containing cells from the leg muscles of rats, the muscle cells showed lower concentrations of methyl groups and more mRNA — a similar effect as seen after exercise — as she expected.

But, says Zierath, that doesn’t mean you can skip the workout for a cup of coffee instead. “Most of the physiological effect of the caffeine we drink is on the central nervous system, and not dispersed to all the muscles,” she says. “In order to get the same kind of effect we saw in the cells, you would have to drink 50 cups of coffee a day, which is close to the lethal dose. In my mind, half an hour of moderately high intensity exercise is sufficient to do the same thing.”

Read more: http://healthland.time.com/2012/03/07/how-exercise-can-change-your-dna/#ixzz2UXQNygP3

Simple Test Predicts Longevity

Simple Test Predicts Longevity
By Lisa Collier Cool
Dec 18, 2012
Yahoo

Don’t be surprised if your doctor asks you to sit on the floor at your next checkup. A new study says testing a person’s ability to sit down and then rise from the floor could provide useful insight into their overall health and longevity.

Brazilian researchers discovered an interesting link between a person’s ability to sit and rise from the floor and the risk of being 6.5 times more likely to die in the next six years. The study, published in the European Journal of Cardiovascular Prevention, included a simple test in which more than 2,000 people ages 51 to 80 attempted to sit down on the floor and then stand back up using as little support as possible.

Floors are Replacing Chairs

Chairs used to be a helpful tool to measure a person’s strength and lower body fitness. Having a person stand up from a seated position helped doctors assess a person's overall frailty and also if he or she is likely to fall (and thereby at an increased risk of fracture). It also measured a person’s lower-body strength and agility.

But this new test has some real life applications.

Instead of simply gauging a person’s ability to get up off the couch, the sitting test helps identify risks associated with picking up vital items—such as medicine or eyeglasses—that may drop on the floor. It also can identify those at risk of spending hours (or longer) on the floor after a fall—unable to get up or call for help.

Aiming for a Perfect Score

The test used by the researchers required people to sit on the floor from a standing position and then return to a standing position. Speed wasn’t a factor in the scoring, but support was.

The more support a person required—including bracing with a hand or knee or both—the lower the score for each action. A perfect score of five for each action (sitting and standing) was the goal. Points and half points were deducted for things like touching a hand or knee on the ground or pushing off with a hand on one knee to stand up. Looking wobbly on the way up or down cost participants half a point.

More than half the participants ages 76 to 80 failed the tests, scoring 0 to 3. Not surprising around 70 percent of those under 60 earned a near perfect or perfect score of 8, 9, or 10.

Scores and Life Expectancy

People who scored 0 to 3 were 6.5 times more likely to die during the course of the 6.3 year study, compared to people who scored from 8 to 10. Those with scores of 3.5 to 5.5 were 3.8 times more likely to die as the high scorers—and those who scored in the 6 to 7.4 range were 1.8 times more likely to die than those with the highest scores.

During the course of the study 159 of the 2,000 volunteers died, with the majority of the deaths coming from the group that had the most trouble getting up and down.

“Just two subjects that scored 10 died in the follow-up of about six years,” said Claudio Gil Soares de Araújo, a professor at Gama Filho University in Rio de Janeiro who worked on the study. If someone between the ages of 51 and 80 scores 10, “the chances of being alive in the next six years are quite good,” he said.

“A 1-point increment in the [sitting-rising] score was related to a 21 percent reduction in mortality," reported the investigators who noted this is the first study to demonstrate the prognostic value of the sitting-rising test,” said Araújo.



It’s Not Just About Getting Up

The ease with which a person stands and sits clues doctors in to a person’s ratio of muscle power to body weight. But the researchers say there are other relevant issues. “It is well known that aerobic fitness is strongly related to survival, but our study also shows that maintaining high levels of body flexibility, muscle strength, power-to-body weight ratio, and coordination are not only good for performing daily activities but have a favorable influence on life expectancy,” said Araújo.

What You Can Do

All is not lost if you don’t score a perfect 10. Doctors say physical activity like walking, swimming, yoga, and weight-resistance training can help improve scores on the sit/stand test and add years to your life.

In addition, you can boost your level of physical activity with a few little things too.

You can burn up to 100 more calories a day if you park in the spot furthest from the door at the grocery store, use the stairs instead of the elevator or escalator at the mall, or make multiple trips up and down the stairs when you’re putting away laundry. “Those little things add up to a lot of beneficial exercise you don’t realize you’re doing,” says Rose Marie Robertson, M.D., chief science officer, American Heart Association.

They can also help you increase your sit/stand score.