Protein content of women's saliva changes with advancing age, describe scientists

In a step toward using human saliva to tell whether those stiff joints, memory lapses, and other telltale signs of aging are normal or red flags for disease, scientists are describing how the protein content of women's saliva change with advancing age. The discovery could lead to a simple, noninvasive test for better diagnosing and treating certain age-related diseases in women, they suggest in a report in ACS' Journal of Proteome Research, a monthly publication. These diseases include lupus, Sj-grens syndrome (associated with dry mouth and dry eye), and other immune-related disorders that affect millions of women worldwide, often at higher rates than in men.

John Yates and colleagues note that human saliva contains many different proteins involved in digestion, disease fighting, and other functions. Scientists are seeking ways to use the proteins as molecular "fingerprints" to develop quick diagnostic tests that provide an alternative to the needle sticks currently needed for blood tests. To do that, they need detailed information on how normal aging affects these proteins.

The scientists analyzed saliva proteins in healthy women aged 20-30 and 55-65. They identified 293 proteins differed between the two age groups. Most were involved in the immune system's defenses against infection. Older women had almost twice as many immune-related proteins than younger women. The results suggest that "it is critical to take into consideration these normal differences in protein expression when searching for clinically relevant, disease specific biomarkers," the article notes.