A zebra can't change its stripes, but according to a new study from Lund University in Sweden, we can change our DNA. We just have to get on the treadmill more often.
The study, published online in PLOS Genetics, followed 23 men during 6 months, all of whom were slightly overweight but relatively healthy.
Though they were not involved in any physical activity before the study, the men were instructed to attend three spinning or aerobics classes each week.
A testament to their previous habits, they only attended an average of 1.8 sessions per week. In addition, the participants were instructed not to change their diet or normal daily activity level.
During the course of the study, researchers examined changes in methyl groups - molecules that reside within genes - in the fat cells of the men. These methyl groups affect what is knows as "gene expression," which determines whether genes are activated or deactivated.
Cells in the body - including fat cells - contain DNA, which is where our genetic information is stored.
Epigenetics, the study of changes in gene expression on a cellular level, plays a big part in the new research. "Our study shows the positive effects of exercise," says Charlotte Ling, associate professor at Lund University. She notes that "the epigenetic pattern of genes that affect fat storage in the body changes."
Researchers were able to see that epigenetic changes had taken place in 7,000 genes - 35% of an individual's genetic makeup.
Tina Rönn, associate researcher at Lund University, said that this "suggests that altered DNA methylation as a result of physical activity could be one of the mechanisms of how these genes affect the risk of disease."
According to Rönn, these types of changes have not previously been studied in fat cells. As a result, they have been able to map the DNA methylome in fat.
The study notes that the long-lasting effects of regular exercise are still not completely understood.
Most studies have previously looked at cellular and molecular changes in skeletal muscle, but this recent study is unique in that it focuses on molecular changes in fat. Though our genes are inherited and therefore cannot be changed, the methyl groups within genes can be influenced by various factors, such as exercise, diet or lifestyle.
The researchers were able to study the cell cultures in test tubes in their lab; by deactivating certain genes, they were able to reduce their expression. As a result, fat storage changed within each cell.
We have long known that exercise is good for our bodies, but we now understand how fat storage in the body can change within our genetic makeup.
The study is the first to link exercise to adjusted genetic expression, potentially affecting how fat cells' metabolisms work - giving new meaning to the axiom that going to the gym "transforms your body."