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Our Genes

Why Your Genes Aren't Your Destiny

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At one time scientists believed our DNA held the key to preventing and reversing disease. But we now know that our environment—not our genes—is the primary driver of health and longevity.

578 (1)The 20th century was the golden age of genetics. It ushered in the discovery of the double-helix structure of DNA, the polymerase chain reaction (PCR) method of amplifying DNA, and ultimately, the sequencing of the complete human genome.

Somewhat understandably, these remarkable discoveries led to "biological determinism," the belief that human behavior and health is mostly—if not entirely—controlled by our genes. And it generated some pretty bold proclamations:

We now have the possibility of achieving all we ever hoped for from medicine.

Lord Sainsbury, Former UK Science Minister
Mapping the human genome has been compared with putting a man on the moon, but I believe it is more than that. This is the outstanding achievement not only of our lifetime, but in terms of human history.

Michael Dexter, The Welcome Trust
But it quickly became apparent that these heady promises weren't going to pan out. Even Craig Venter, one of the first scientists to sequence the human genome, recognized the limitations of using genes to predict and prevent disease:

We simply don't have enough genes for this idea of biological determinism to work.

Craig Venter, Chairman and CEO of J. Craig Venter Institute
We now know that genes account for about 10 percent of human disease.

So if our genes aren't driving disease, what is?

The Exposome as the Primary Driver of Health and Disease

The "exposome" is a concept that was originally proposed by Dr. Christopher Wild in 2005. (1) It refers to the sum of all non-genetic exposures in an individual lifetime, starting from the moment of conception. It encompasses everything from the food we eat, to the water we drink, to the air we breathe, to the social interactions we have, to the lifestyle choices we make, to the health of our parents at the time of our conception.

In short, it's the word scientists are using to describe the full range of environmental exposures that influence our health.

Genes may load the gun, but environment pulls the trigger.