Last fall a study was published in the New England Journal of Medicine that raised hopes concerning the growing health problem of obesity with DNA editing.
Researchers at Harvard University, MIT and the Broad Institute of Cambridge had identified a variant of the gene FTO that is thought to be responsible for the development of fat cells in the body and thus seen as one of the causal factors for weight gain.
In Canada, obesity rates have tripled since 1985 and it is projected that 21% of Canadians will be classified as obese (having a Body Mass Index (BMI) of 30 or higher) by the year 2019. Elsewhere, in the United Kingdom obesity rates have climbed from less than 3% in the 1970’s to 25% today. But what proved newsworthy was not the isolation of the FTO gene variant but that researchers had been able to alter living cells in mice carrying that variant using the new gene editing tool, CRISPR/Cas9. A few snips later and voila – the mice showed reduced body weight and increased energy dissipation.
Too good to be true? Scientists are still figuring out the uses and limitations of CRISPR but what is obvious is that this technology is a game changer. DNA editing has been around for a while yet the difference with CRISPR is that it is a much more precise and efficient tool, allowing scientists to work within a scale and time frame not possible before.
This provides a message of hope for people with obesity predisposing genes that they can do something about it. Our body weight destiny is not only written in our genetic blueprint.
“We now have the circuits and can turn the knob to energy storage or energy dissipation,” said Manolis Kellis, one of the Harvard study’s authors.
Fast forward to the present, as researchers at McMaster University released another study on the FTO gene, this time showing that physical activity can blunt FTO’s effects on the body. Published in the journal Scientific Reports, the comprehensive study looked at both the genetics and behavior of 17,400 people from six ethnic groups over the course of three years. The results showing that physical activity can significantly lower the effect of the FTO variant.
“This provides a message of hope for people with obesity predisposing genes that they can do something about it. Our body weight destiny is not only written in our genetic blueprint,” says David Meyre of McMaster’s Michael G. DeGroote School of Medicine.
At this point, the question to ask is should we care anymore about the exercise route? Why not just wait for the quick gene-splicing fix that seems to be right around the corner?
From where we stand at the moment, two things to mention: one, the FTO variant is only one of 14 genes that are thought to predispose for obesity. And in terms of weight gain or loss, FTO is said to account for a difference of about 3 kg on average -not insignificant, but certainly not the whole story when it comes to obesity.
Two, although revolutionary, CRISPR’s clinical trial days are still a ways off. For instance, in an article in the New Yorker magazine, Dieter Egli, a stem-cell researcher at Columbia University says, “This type of technology is not ready for any kind of application.”
One thing is certain, though. Gene science and DNA editing are about to play a far greater role in everyone’s life. Stay tuned.