Wednesday September 5 2007
Obesity is currently at high levels worldwide.
A single gene could hold the answer for tackling obesity, news sources reported. A research team has identified a particular gene called adipose that affects whether fat was gained across a range of organisms that were tested including mice, fruit flies, and worms.
It is proposed that this gene acts as the “master-switch” that tells the body what to do with fat that is taken in the diet. The Daily Mail and The Guardian quote the lead researcher who said “From worms to mammals, this gene controls fat formation.”
All animals, including humans, carry two copies of the gene, and the newspapers report that if it could be targeted, it could lead to the development of new treatments to fight obesity, a condition which is linked to disease and death, and which is currently at high levels worldwide.
The Daily Mail speculated that this research could lead to drugs that “trick the body into shedding fat”, and that “such pills could give men and women a trim body without any visits to the gym.’
This is an experimental animal study. It is too early to draw conclusions on the role of this “fat gene” as a cause of obesity in humans. The tried and tested method of reducing how much you eat and getting at least a modicum of exercise is still the most advisable course of action for weight loss. It will be for the foreseeable future.
Where did the story come from?
Jae Myoung Suh and colleagues from the Departments of Developmental Biology, Molecular Biology, and Internal Medicine, of University of Texas, USA, conducted this research. The study was funded by NIH and NIDDK. The study was published in the peer-reviewed scientific journal, Cell Metabolism.
What kind of scientific study was this?
This was an experimental study carried out in mice, microscopic worms, and fruit flies. It investigated the theory that a certain gene called the adipose (Adp) gene, plays a role in the accumulation of fat in fat cells and may be involved in the mechanism underlying weight gain and obesity. The researchers were looking at this gene because a naturally occurring mutation in this gene had been found to cause obesity in fruit flies.
The researchers conducted several different experiments looking at what happened when either mutated or normal copies of the Adp gene, were introduced into mice, microscopic worms, or fruit flies.
First they examined what happened in the worms when they stopped both copies of the gene from working. Then they genetically engineered flies that had either a single copy or a double copy of the mutated gene, and compared these to normal, flies who had not had their genes mutated.
They then repeated these tests in mice. They also looked at the effect of increasing the gene’s activity in mice, by genetically engineering mice to have extra copies of the normal gene.
The cells of the flies and mice were then examined to look at the fat content.
What were the results of the study?
Researchers found that when they stopped the Adp gene working in microscopic worms, the worms became obese.
Similarly, they found that flies with the double copy of the mutant Adp gene were obese and had decreased mobility. Flies with a single copy of the mutant gene were also more obese than normal lean flies, but not as obese as flies with two mutant copies.
The researchers found similar results in the mice. They also found that if they genetically engineered mice to have extra copies of the normal gene, they were leaner than normal mice, even though they ate about the same amount, and were similarly active.
What interpretations did the researchers draw from these results?
The researchers conclude that the Adp gene seems to play a similar role in the different types of animals they looked at, and that if both copies of the gene are mutated, it doubles the effect compared with if only one copy was mutated.
They say that Adp appears to be involved in the process within the body that regulates fat accumulation. The researchers speculate that by increasing the activity of the gene, fat gain is prevented which may “indicate therapeutic potential”.
What does the NHS Knowledge Service make of this study?
This was an animal study conducted in microscopic worms, flies and mice. Although this gene seems to play a similar role in these organisms, it is not possible to say at this time that it will behave similarly or have any potential therapeutic use in humans.
We also do not know that altering the adipose gene in humans is possible, or that it would produce the same effects in humans in affecting fat accumulation.
Until further research is carried out is is impossible to conclude that any new “weight-loss-pill” could be on the horizon.
Sir Muir Gray adds…
Genetic factors play a part but the principal reason why obesity has increased in the last 20 years has been the decline in exercise resulting from greater car ownership and use. Everyone who wishes to lose weight should try to adjust their lifestyle to walk an extra 3000 steps or 30 minutes a day. They should worry about jeans not genes and, if overweight, aim to reduce their waist by two sizes in six months.