Genes Are Not Destiny? What’s That Supposed to Mean?

Facts are stubborn because they’re real. Two new studies in Cell today shine a light on a basic fact about obesity that we’ve known for decades. Obesity is a highly heritable condition. Roughly 70 percent of a person’s risk of obesity is driven by the genes they inherit. But some people work awfully hard to skate around this fact.

Gene Variants to Protect Against Obesity

In the first of these two studies, Luca Lotta and a team of scientists worked with Sadaf Farooqi at Cambridge. Together, they discovered variants of the melanocortin-4 receptor that serve to protect some people from obesity. Farooqi explains:

This study drives home the fact that genetics plays a major role in why some people are obese – and that some people are fortunate enough to have genes that protect them from obesity.

Understanding this pathway can serve as a blueprint for better obesity treatment options.

A Genetic Risk Score

The second of these two studies comes from a team at Harvard. Amit Khera et al demonstrate how a genome-wide risk score can quantify inherited risk of obesity. That risk, they found, starts showing up in a child’s weight as early as the age of three.

Lee Kaplan, President-Elect of the Obesity Society, was one of the co-authors and explains the importance of this finding:

The bottom line is that this opens up a whole new list of questions that can be asked and answered.

The Prevailing Bias About Obesity

These facts about the heritability of obesity are stubborn and robust. They keep coming, but some people have a tough time with them. Sara Bramblette of OAC’s Board of Directors explains:

There’s a huge amount of weight bias in society that starts from when you’re a kid. Kids get bullied in school early on because the idea out there is that you’re just being lazy and eating too much.

Faced with these facts, some people start pumping out aphorisms. “DNA is not destiny. You have a choice to make. Buck up. Be the author of your own future.” Well-meaning people try to take the edge off unpleasant truths. Maybe they think it will inspire us.

But facts are facts. Some people inherit physiology that puts them at a high risk of obesity. Some do not. We deal with it. Facts and science are more inspiring that empty (and usually false) generalizations.

Click here for the study from Lotta et al and here for the study from Khera et al. For further perspective on this important research, click here and here.

Destiny, photograph © Guy Mayer / flickr

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April 19, 2019

3 Responses to “Genes Are Not Destiny? What’s That Supposed to Mean?”

  1. April 19, 2019 at 9:31 pm, David Brown said:

    Predisposition to pack on weight is not the cause of the global obesity epidemic. We can blame that on changes in the fatty acid profile of the food supply. The big problem, the one that is not discussed, is the tremendous increase in omega-6 linoleic acid in fat stores of animals and the increase in omega-6 arachidonic acid in lean tissue. Besides humans, this change has also affected pets and laboratory animals as noted in this paragraph.

    “Animal feeds were also subject to the change from a low to high omega-6 content with the incorporation of vegetable oils, and this has led to and increase in obesity in domestic and laboratory animals.Laboratory animals, whose housing and husbandry practices have not changed much in the last 50 years, now have a much increased mid-life body weight.”

    • April 20, 2019 at 4:12 am, Ted said:

      Thank you, Chester and David, for the reminder that environment has an important role to play. Our environment is presently triggering more obesity in more susceptible individuals. It takes both genetic susceptibility and environmental triggers. A susceptible individual will not suffer from obesity in the midst of a famine. A resistant individual stays thin, even in an obesogenic environment.

  2. April 19, 2019 at 10:14 pm, Chester Draws said:

    Our genes haven’t changed in the last 200 years, yet our obesity rate has dramatically. In Asia the change has occurred in a generation.

    Whatever is causing so many people to be obese cannot be primarily genetic.