Weight-loss surgery may alter genes

Written By Amanda Woerner for Fox News

We all know that weight-loss surgery can shrink your waistline – but a new study shows it can cause surprising changes in your genes, too.

According to a study in the journal Cell Press, people who underwent gastric bypass surgery and lost weight, experienced changes in gene expression, which improved their body’s ability to burn fat and store sugars properly, decreasing their risk for diabetes.

“If you are a person who has been struggling with (sic) weight, the good news is that if you lose that weight you can restore the metabolic health of the muscle,” senior study author Juleen Zierath, a professor at the Karolinska Institute in Stockholm, Sweden, told FoxNews.com. “You aren’t damaged for life.”

The study delved into the epigenetics – chemical modifications imposed externally on genes by lifestyle or environmental influences – of the skeletal muscles in eight obese women, scheduled to undergo gastric bypass surgery, and 16 women of normal weight.

Researchers focused specifically on two genes that control glucose and fat metabolism, PGC-1alpha and PDK4. They found the DNA of the obese women contained chemical markers that prevented these genes from functioning normally.

“We could map out that the obese women had lower expressions of proteins that burn fat and store glucose,” Zierath said.

At the start of the study, each of the obese women had a body mass index of around 40, and weighed between 265 to 320 pounds. Six months later, after the surgery, they had each lost approximately 70 pounds.

Researchers then took another look at the genes of the overweight women – and found they no longer displayed the chemical markers that were there when the women were obese.

“The DNA itself doesn’t change, but the way in which the code is marked by chemical tags is changed,” Zierath said. “After the surgery, (the obese women’s) gene expression changed to look like that of the healthy women.”

Zierath added that this was surprising because “people have really believed that the chemical marks on DNA are fixed, and it isn’t really a flexible process.”

Obesity causes an increase of lipids, or fats, in the blood, as well as high levels of cytokines, which are markers of inflammation, according to researchers. In turn, this affects the way the body functions.

“Cytokines and blood lipids attack the muscle and change the profile of the chemical markings on the DNA – and impairs the muscle from burning fat and storing sugar the way it is supposed to,” Zierath explained.

Researchers discovered that after the participants lost weight, their cells were able to function appropriately again.

“When people lose weight, inflammation and blood lipids decrease, and cease to attack the muscle as much,” Zierath noted, which allows the muscles to reprogram themselves, and build up proteins that burn fat and store sugar in a good way, improving metabolic health.

Zierath also noted that if obese women lose weight before having children, they may be able to avoid passing on these types of negative gene traits to their offspring.

“You can take some control over your genetic destiny,” Zierath said.