It may be possible in the not-so-distant future to screen for diseases and behavioral problems with a simple sample of saliva. For people with hard-to-diagnose illnesses like CFS and FM, this may be the biggest news of the century.
The practical implications of using saliva as a diagnostic fluid are enormous, says Dr. Douglas Granger of Penn State. According to Granger, saliva testing is readily accepted in Europe, but it has been slow to catch on in the United States.
From health monitoring to drug testing, saliva could become the diagnostic testing fluid of the future. It could revolutionize medical care and its impact could be felt everywhere from medical clinics to businesses interested in monitoring employees health.
Parents won’t have to subject their children to painful blood tests. Rather than go through invasive exams to test for cancer or HIV, patients could just submit a saliva sample. A simple swab of a patient’s saliva could be used to screen for everything from cancer to how a child may develop emotionally. It could someday provide an easy, cost-effective method for businesses to test for drugs or for insurance companies to check an applicant’s health.
The practical implications of using saliva as a diagnostic fluid are enormous. Saliva testing is readily accepted in Europe, but it has been slow to catch on in the United States. That’s unfortunate. Saliva could be the diagnostic fluid of the future.
One of the first applications of saliva assays has been to screen for HIV infection. In the future, it is possible that saliva might be used to diagnose other infections and possibly cancer. Collecting saliva is considerably less intrusive, painful and inconvenient for the donor than blood or urine samples. It can also be used for testing populations that aren’t easy to test using blood such as infants, hemophiliacs, and those who feel squeamish or uncomfortable with blood.
Gathering samples is a simple process, too. The person giving the sample typically spits into a tube. Although drug testing is perhaps the most obvious use of saliva tests for employers, saliva could be a means to measure employee stress by testing for stress-related chemicals, such as cortisol. In order to do that, however, the Food and Drug Administration would have to approve the tests as a diagnostic to test for stress levels in jobs.
Companies also could use saliva testing while doing trials for new products. For instance, testing nicotine patches requires multiple samples of a biological fluid. With saliva testing, product developers could monitor hormonal changes every day so they can fine-tune dosages.
Saliva tests can be used to measure testosterone levels. Higher levels of testosterone have significant health benefits for some middle-aged men. Men with higher testosterone are less vulnerable to high blood pressure, heart attacks, frequent colds and obesity.
In addition, they are more likely to rate their health as excellent or good rather than fair or poor. Studies show self ratings of health correlate highly with physicians’ assessments. However, some, but not all, men with higher levels of testosterone are more likely to engage in behavior that cancels out the beneficial effects of testosterone such as being more likely to smoke.
Saliva assays can test cortisol levels, too. Cortisol is a hormone linked to stress, anxiety, depression and socially withdrawn behavior. Children who are more socially withdrawn or anxious are more likely to have an increased level of cortisol in their bodies. This is in response to stresses like social conflicts with their parents. Other research has shown that high levels of cortisol are associated with changes in the immune system, emotional problems and perhaps memory impairments
It also can be used to study DHEA (dehydroepiandrosterone) levels in children and adults. Many people look at DHEA as a supplement to enhance aspects of their cognition, mood and health. Research also shows that DHEA plays a key role in the physiology of stress, is associated with major developmental milestones during middle childhood that set the stage of the transition to puberty, and DHEA is the major precursor of testosterone in females.
We’ve recently discovered that DHEA can be accurately measured in saliva. This is important, because researchers can now monitor the levels of this hormone in people’s everyday social worlds. By studying hormones and behavior in social context researchers expect to learn new information about how biology and behavior interact with the environment to produce differences in developmental and health outcomes.
We’re just starting to see the impact this research can have on the quality of our lives.
Douglas Granger is assistant professor of biobehavioral health
in Penn State’s College of Health and Human Development and is director
of Penn State’s Behavioral Endocrinology Laboratory, which specializes in saliva assays.