WASHINGTON, April 19 (UPI) -- Saliva may eventually answer why your kid could be happy, sad or spitting mad, according to a new study.
By analyzing kid drool, researchers have gained insights into social stressors, such as relationships with parents and teachers, and how these stressors affect child development.
Alpha amylase, an enzyme secreted by the salivary glands, differs from person to person and can be a marker for the response to the sympathetic nervous system, or the body's flight or fight response.
"We've opened up a big can of worms -- there's a whole bunch of things we have not seen yet," lead author Dr. Douglas A. Granger, a professor at Penn State University, told UPI.
The results came from four separate studies of children and their mothers.
Amylase is regulated by another branch of the stress system than cortisol, a stress hormone. Amylase does not specifically cause stress -- it is a marker present when stress levels are elevated, for example.
Scientists have already relied on biomarkers in saliva to study social behavior and stress vulnerability in adults, and this study shows for the first time such methods can also work in children.
"Now we can measure both branches of stress system in kids. We can do it without having to stick them (with needles), we can do it in their everyday social world, and we can do it with a volume of saliva that's a teeny tiny amount," Granger said.
Testing spit has obvious advantages over analyzing urine or blood, as it is a less-invasive method for repeated sampling and enables easy collection, the authors wrote. The method also enables researchers to reach populations who might be underrepresented in other research.
The research appeared today in a special issue of the Journal of Social and Personal Relationships.
The studies confirm developmental differences in the amylase proteins. For example, infants, preschoolers and elementary school-aged children did not show stress-related increases of the protein. But adolescents and young adult mothers do have an increase in amylase activity.
In addition, 8- and 9-year-olds who had higher amylase levels also encountered more social problems, aggressive behavior, and cognitive difficulties.
It's possible the saliva tests could be someday used as a diagnostic tool for social behavior, Granger added.
Other consumer-health tips and tidbits:
-- Speaking of kids, new evidence suggests they should be careful around their pet fish: An Australian study in the March issue of Emerging Infectious Diseases has found touching or interacting with tropical fish can spread bacterial infections serious enough to send kids to the hospital with high fever and bloody diarrhea.
The culprit? A strain of salmonella, which also can be transmitted from pet reptiles, chicks, ducklings and other animals, The New York Times reports. As many as 12 million American families own domestic aquariums.
-- An osteoporosis drug, raloxifene, reduces risk for breast cancer, according to a study of nearly 20,000 postmenopausal women. The drug, sold as Evista, prevents estrogen from causing cancer in breast tissue. Another drug, tamoxifen, has been a common stand-by for doctors hoping to reduce breast cancer in high-risk women. Evista's manufacturer, Eli Lilly & Co., plans to seek Food and Drug Administration approval to market the drug as a cancer-preventer, the Washington Post reports.
-- Eating the Mediterranean diet significantly cuts risk of Alzheimer's disease. In a study of 2,200 people monitored over four years, those who followed the diet -- composed of fruit, vegetables, cereals, fish and some alcohol -- fared better than those who did not. The study, published online April 18 in the Annals of Neurology, adds evidence to findings that diet and lifestyle play a role in the development of the disease, the BBC reports.
--
E-mail: [email protected]
