A new, non-invasive test might reveal whether someone is at greater risk for various diseases. Researchers are using the exam - which involves a saliva sample - to adjust the diets of "at-risk" patients. But some doctors say that, at least for now, the test raises more questions than it answers.
Andrew Betterman is one of many volunteers providing a sample of his saliva, to help researchers chart his medical future.
"The pamphlet suggests it will tell you about your cardiovascular health, your bone health," Andrew explains.
Using a mail-order kit, Mister Betterman collects a sample of his saliva, and then sends it to a lab in Seattle, where it is screened for variations or changes involving 19 specific genes.
"If you have these variations, you can make changes to your current dietary or lifestyle habits," Christine Ashcraft, with the Genelex Corporation, the testing lab analyzing the samples says.
For example, a variation found in a gene called MTR has been associated with heart disease. So researchers suggest people with that variation increase their intake of "B" vitamins. Changes in a gene called VDR have been linked to weak bones. Doctors say people whose tests shows that variation need more calcium and Vitamin D in their diets.
"They know what they need to focus on. They know what's most important for their own unique body," Christine Ashcraft explains.
The test, called the "nutrional genetic panel” can cost $400,000. Some nutritionists say it's a waste of money.
Doctor Steven Zeisel, from the University of North Carolina says, "We just don't know enough to use those types of tests effectively."
Critics say the test is not an accurate predictor of potential health problems. They say analyzing just 19 out of the more than 20,000 genes in the human body cannot determine which people face elevated risks.
"It's very naive to focus on a few select genes for any given disease. We know there are many contributors, genetic contributors to every complex disease," Professor Jim Fleet, from Purdue University says.
Another criticism: there is no concrete information concerning how much a person must increase his or her intake of certain vitamins to ward off disease. In the meantime, most researchers say people should practice common sense, and eat a healthy, well-balanced diet.