The study may pave the way for a new type of weight loss medication!
Many of us may have noticed – with a fair degree of apprehension – that we tend to gain weight a lot more easily as we age. The general perception is that this is due to poor lifestyle choices, but a new study suggests that an enzyme may be responsible for midlife weight gain.
Obesity can generally be prevented with a healthful diet and plenty of exercise, but sometimes we continue to gain weight despite our best efforts. For instance, people tend to gain weight as they age – particularly around the belly – and can subsequently become overweight, in a phenomenon commonly known as midlife weight gain. In fact, it is estimated that the average U.S. adult gains 30 pounds between the ages of 20 and 50, despite the fact that people tend to eat less during this period.
Researchers set out to investigate the mechanism behind midlife weight gain. They investigated the biochemical transformations that take place in animals in their middle age. The team found that an enzyme – called DNA-dependent protein kinase (DNA-PK) – becomes more active with age. Furthermore, the researchers found that DNA-PK turns nutrients into fat and lowers the number of mitochondria ( mitochondria are responsible for producing as much as 90 percent of energy in every cell in the body). The younger we are, the more mitochondria we have. From midlife onward, however, the number of mitochondria starts to decrease – this lower number can lead to obesity, and has been associated with a decrease in one’s ability to exercise.
To further understand the role of the DNA-PK enzyme, researchers tested its effect on two groups of mice. Both groups were fed a high-fat diet, but one group received an inhibitor that blocked the DNA-PK enzyme, while the other group did not.
The group that received the DNA-PK-inhibiting drug gained 40 percent less weight than those that did not receive the drug. Additionally, the drug increased aerobic fitness and decreased the rate of obesity and type 2 diabetes in obese, middle-aged mice. Finally, the inhibitor also increased the number of mitochondria in the mice’s skeletal muscle.
Although we are a long way from developing a similar DNA-PK inhibitor for humans, this new study may pave the way for developing an innovative kind of weight loss medication. In the meantime, this new information should not discourage people from eating healthy and exercising!