Research is Identifying Genes that Lead to Obesity and Why Some People Stay Lean
Obesity has become an epidemic, caused in large part by a high-calorie diet high in sugar and fat. The increasingly sedentary lifestyle also has negative effect on our figure. Moreover our genes play a vital role, regulating fat storage and influencing how well our body use food for fuel. Some people are naturally fortunate to be lean and able to eat whatever they want without gaining weight, while for others every calorie counts on the scales right away. But is there a way out of this vicious circle? Possibly. Science is working to find ways to combat obesity in the long term. Among other things, researchers are trying to identify genes that convert overeating into fat in order to switch it off with medication. This could have an immense impact on people with weight problems.
Does a Gene for “Thinness” Prevent Weight Gain?
Could a particular gene be responsible for some people just not gaining weight? In the “Identification of ALK in Thinness” study, researchers shed light on genomes from an Estonian gene bank of 47,000 genomes. They recruited a cohort of 20- to 24-year-olds and specifically looked for people with a low body mass index. This revealed a number of genes that are associated with a slim figure. One gene turned out to be particularly notable: it’s called ALK, and it seems to have the biggest impact on being thin. In fact, it affects energy expenditure and metabolism, and can affect parameters such as waist circumference, blood sugar and cholesterol levels.
To conduct further investigations, the scientists removed this particular ALK gene from the genomes of mice and flight flies. It was found that mice without the ALK gene had faster energy expenditure (the amount of energy that a person converts over a period of time) and burned calories better than the unmodified animals. Researchers found that the hypothalamus (the area of the brain involved in regulating hormones) has something to do with it. Rodents with the ALK gene suppressed in this area were also able to burn fat, which appeared to be the result of increased levels of norepinephrine (stress hormone) in adipose tissue.
ALK Inhibitors Against Obesity
The good news: The results were comparable to tissue samples from thin people, which the researchers also analyzed. ALK inhibitors already exist in the form of drugs to counteract cancer. This raises the question of whether this gene could also help in the fight against obesity. The scientists are confident that in the future it will be possible to inhibit ALK to treat obesity, but further research is necessary to determine whether the animal models can be extrapolated to humans and if there are side effects of ALK inhibitors to expect.
14 Genes are Linked to Being Overweight
Research from the University of Virginia has also confirmed that genes play an important role in relation to weight. Scientists have discovered 14 genes that can lead to weight gain, while three could prevent it. In fact, genomics scientists have discovered hundreds of genes linked to obesity. Affected people have higher levels of these genes than those of normal weight. To determine exactly which genes are involved, the researchers used a genus of worms, also known as C. elegans, to study 293 genes associated with obesity in humans. They developed a worm model for obesity. Some of the worms were given normal food, the others a high-sugar diet.
Future Therapies Could Not Only Fight Obesity, But Also Make it Possible to Live Longer
Her research showed that 14 genes are the cause of obesity, while three counteract weight gain. These not only prevented obesity, but also helped the worms to have a longer life. But there are other advantages: if specific genes are blocked, insulin sensitivity can be improved and blood sugar levels lowered at the same time. While this research is ongoing, the results are promising as they pave the way for targeted treatments to combat obesity. Anti-obesity therapies are urgently needed to reduce the burden of obesity on patients and the healthcare system.