- Scientists at the National Institutes of Health say an enzyme drives post-30 weight gain
- They managed to block that enzyme in middle-aged mice, causing weight loss
Scientists are one step closer to a pill to stop the middle-age spread, a new paper claims.
New research shows 40 percent of weight gain in our 30s, 40s and 50s is driven by a particular enzyme, making it harder to keep the pounds off.
And now, scientists from the National Institutes of Health claim to have identified the offending enzyme – and say they can see a way to block it.
During trials on mice they discovered that, by administering drugs to blocked the enzyme, the the rodents lost almost half their excess body weight compared to a control group.
Scientists from the National Institutes of Health claim to have identified the offending enzyme that causes weight gain after we hit 30 – and say they can see a way to block it
Lead study author Dr Jay Chung, head of the Laboratory of Obesity and Ageing Research at the National Heart, Lung, and Blood Institute, said: ‘Our society attributes the weight gain and lack of exercise at mid-life primarily to poor lifestyle choices and lack of will power.
‘But this study shows that there is a genetic program driven by an overactive enzyme that promotes weight gain and loss of exercise capacity at mid-life.’
Dr Chung and his team used mice to test the potentially key role this enzyme plays in obesity and exercise capacity.
They administered an inhibitor that blocked the enzyme in one group being fed high-fat foods, but withheld it in another.
The result was a 40 percent decrease in weight gain in the group that received the inhibitor.
The study, the first to link the increased activity of this enzyme to ageing and obesity, appears in the current issue of Cell Metabolism.
They believe it could have ramifications for several chronic, obesity-related illnesses such as heart disease, diabetes, and other diseases that tend to increase with age, including cancer and Alzheimer’s.
Researchers have known for years that losing weight and maintaining the capacity to exercise tend to get harder beginning between ages 30 to 40 – the start of mid-life.
Dr Chung and his associates searched for biochemical changes that occurred in middle-aged animals, and found that an enzyme called DNA-dependent protein kinase, or DNA-PK, increases in activity with age.
Further work showed that DNA-PK promotes conversion of nutrients to fat, causing weight gain, and decreases the number of mitochondria, tiny organelles in the cells that turn fat into energy to fuel the body.
Mitochondria can be found in abundance among young people, but the numbers drop considerably in older people.
Dr Chung theorised that reducing DNA-PK activity may decrease fat accumulation and increase mitochondria number as well as promote fat burning, and by blocking the enzyme from working was able to prove his theory.
He added: ‘Our studies indicate that DNA-PK is one of the drivers of the metabolic and fitness decline that occurs during ageing, which makes staying lean and physically fit difficult and increases susceptibility to metabolic diseases like diabetes.
‘The identification of this new mechanism is very important for improving public health.
‘The study opens the door to the development of a new type of weight-loss medication that could work by inhibiting DNA-PK activity.’