Just a couple of weeks ago we celebrated the anniversary of a truly momentous scientific occasion — the completion of the Human Genome Project.
Earlier this millennium a team of researchers mapped the entire human genome, ushering in what was supposed to be an golden era of personalized medicine. Doctors would be able to use our genetic profiles, along with information about our daily lives and personal habits, to practice better preventative medicine and provide better therapeutic care.
The idea is this, if our DNA puts us at risk for developing a disease like diabetes, we would be encouraged to live a healthier life. By eating a more balanced diet and by exercising regularly, we could thus avoid our genetically predetermined fate. We could also be monitored more closely so that disease, should it occur, would be caught early and treated promptly.
In the nearly ten years since the human genome was sequenced, however, we haven’t quite achieved this lofty goal. This isn’t to say that the Human Genome Project wasn’t a success, or that the $3 billion spent on this project was wasted. We’ve used this information to make a number of important new discoveries.
What we have not been able to do in the post-genomic era is translate this treasure trove of genetic information into useful data and concrete action on the part of physicians and patients. Of course, that hasn’t stopped an entire industry from springing up around genetic testing and personalized medicine.
A number of companies now offer genetic testing services. These tests are marketed directly to the consumer, without the involvement of physicians or other health care professionals. For a few hundred dollars, you can mail a sample of your saliva to a lab in California where they will analyze your DNA and provide you with detailed report about your disease risks. Some companies will even provide you with recommendations about nutrition and exercise, and sell you vitamin supplements customized to your dietary needs.
Caveat emptor — let the buyer beware. The genetic testing industry is still largely unregulated and the tests offered are unreliable. A recent investigation by the federal Government Accountability Office, for example, found that different testing companies provided conflicting results for the same DNA sample.
Even when performed accurately, these genetic tests aren’t that useful for predicting individual disease risk. A good family health history is far more predictive of disease risk than the genetic tests currently available. Unfortunately, most of us have never taken the time to ask our parents, our aunts and uncles, and our distant cousins about the illnesses that run in the family. Even when this information is known, doctors rarely have or spend the twenty minutes or more that it takes to collect this information from their patients.
Finally, genetic testing doesn’t help prevent or treat the most common health problems in the US today. These include heart disease, cancer, stroke and diabetes. Most of us will likely suffer from one or more of these ailments at some point in our lives. Truth be told, we already know how to reduce our risk of getting these diseases. Long before the human genome was mapped our doctors had been trying — and failing — to get us to change our generally unhealthy lifestyles. Undergoing genetic testing certainly won’t help with this. In one recent study, even those patients who were found to have a strong genetic predisposition for obesity, diabetes or colon cancer — diseases in which diet and exercise play a major role — neither cut down on the amount of fat that they ate nor increased the amount of time they spent at the gym.
Genetic research and personalized medicine still holds great promise, and we should continue to fund research in this area even during a time of tightening federal budgets. What we should not do is waste our personal resources seeking individualized genetic testing. We’d be better off spending that money on a new pair of running shoes, a new gym membership, a couple of sessions with a personal nutritionist, or a long-distance phone call to Mom asking about her health — we’d certainly be happier and healthier for it.
[This blog entry was originally presented as an oral commentary on Northeast Public Radio on April 28, 2011. It is also available on the WAMC website.]