Molecules Can Cause Weight Gain during Middle Age, Scientists Say

When people start aging, it is normal to put up some extra weight. But a new study has given an explanation saying that weight gain may have no connection with poor food choices or exercise.

Researchers were able to identify that a specific enzyme tends to increase its regular activity with age in animals. This increase in the activity could play a huge role in gaining weight and resulting in decline of fitness with age, according to them.

When experiments were conducted on mice being fed on high-fat diet, the experimenters could determine that those mice with the enzyme blocked did not gain as much weight as the normal ones.

Our society has a way of attributing lack of exercise and weight gain to mid-life, mainly because of lacking will power and poor lifestyle choices, according to Dr. Jay Chung, author of the study from the National Heart, Lung, and Blood Institute. But, the study was able to show that there is a chance of a genetic program led by an overactive enzyme for promoting weight gain and losing the capability to exercise in the middle age, he added.

As the study was conducted on mice, the experimenters are not able to conclude that the effects will be same on humans as they were on the mice. But, they mentioned that with further research in this area, they could gain more insight about this enzyme and discover medications that could help in blocking it.

Chung mentioned that the mere fact of adults gaining weight after reaching middle age used to make him puzzled. An average American citizen is between the ages 20 years and 50 years gains about 30 pounds extra even without consuming more food during this time span, he added.

Chung along with his colleagues were looking into the molecular changes that take place in animals when they reach middle age which helped them figure out the enzyme named DNA-dependent protein kinase (DNA-PK), known for increasing its activity with age.

The study was able to show that DNA-PK was lined with metabolism (that involved converting nutrients into fat) along with producing mitochondria which is known to be the “powerhouse” of a cell for turning nutrients to energy. As the age keeps increasing, the number of mitochondria in the body starts dropping.

While conducting the study, the researchers gave a drug for inhibiting the action of DNA-PK to mice on a high-fat diet. The results showed that the mice gained 40 percent lesser weight as compared to the ones who were not administered the drug.

Adding to the findings, the number of mitochondria in the skeletal muscle cells also increased. The mice were also seen to experience increased aerobic fitness.

The studies were able to conclude that DNA-PK had a role in fitness and metabolic decline with age, making being physically fit quite difficult with age, according to Chung.

However, the importance of exercise and diet should not be underestimated while getting older as they are still considered to be the primary tool in fighting obesity.