Within two years, you may be able to go for a regular dental visit, spit into a cup and before your appointment is over, find out from an analysis of your saliva whether you're at risk for oral cancer.
Currently, dentists have to do a thorough mouth exam to probe for oral cancer, which will strike more than 28,000 Americans a year and kill more than 7,000.
Within a few more years, a fancier spit test may determine whether you're at risk for a number of other diseases as well, including breast cancer, Type 2 diabetes, ovarian cancer, Alzheimer's disease and rheumatoid arthritis.
If you're among the avant garde, you might even have a tiny chip implanted in your cheek to monitor proteins in saliva such as CRP, a protein that is often linked to an increased risk of heart disease. With constant monitoring, the chip could sound an alarm -- maybe a beep, maybe an electronic message to your doctor -- whenever levels of a particular protein are too high or too low.
Until a few years ago, the technology to analyze minute quantities of genetic material and proteins in saliva was simply not good enough for many of the tests doctors want to do or tests consumers could do in the privacy of their own homes, said Dr. David Wong, associate dean of research at the UCLA School of Dentistry and co-director of head and neck cancer research program at the Jonsson Cancer Center at UCLA.
In the brave new world of genomics and proteomics -- the study of genes and the proteins they make -- the best body fluid to analyze disease risk may soon be saliva, not blood. Saliva, the slippery fluid that helps moisten and digest food, is a medical gold mine because it is almost identical to the clear part of blood, but with everything, including infectious organisms, present in weaker concentrations.
Saliva testing is less invasive, less painful, less likely to cause infection and potentially cheaper than blood testing because there's no need for a phlebotomist to draw blood. And because it's so easy to test saliva repeatedly during the day, doctors believe they will be able to use saliva-based tests to keep track of real-time physiological changes such as how an infection is responding to antibiotics.
The idea of using saliva for detection is not new. Among ancient peoples, legend has it that saliva was used as a primitive lie-detector test. A person accused of wrongdoing would be given a handful of rice and told to swallow it; if he couldn't, it meant he was dry-mouthed, nervous and guilty.
