(By Dr. Joseph D. Lim and Dr. Kenneth Lester Lim, BS-MMG, DDM, MSc-OI)
TO SPIT it out, saliva is a very important and essential part of life.
It is a complex fluid whose physical and chemical properties make life possible. Some of the roles of saliva are important to all species.
Saliva is often taken for granted. And yet its importance cannot be overemphasized.
Imagine: without saliva, food cannot be tasted; saliva dissolves the molecules to enable a person to taste the food.
Without saliva, it would be extremely difficult if not impossible to ingest food. The mucus in saliva binds the food that is chewed into a slippery bolus that slides effortlessly into the esophagus without damaging the mucosa. Saliva digests dietary starch and turns it into maltose.
The constant flushing which saliva does in the mouth gets rid of food debris and keeps the mouth relatively clean. Saliva also contains lysozyme, an enzyme that prevents the proliferation of bacteria in the mouth. Dragon breath, or the slight bad breath in the morning, happens because there is less saliva flow during sleep, enabling bacteria to build up.
Saliva gets the attention it deserves when it affects oral and overall health, playing an important role in the diagnosis and prevention of diseases. It is said that it is even more precise than the blood when it comes to testing for diseases.
Blood analysis looks at compounds as they travel through the blood serum most of which are bound to protein. Unlike blood testing, saliva analysis looks at the biologically active compounds at the cellular level, a more clinically relevant level.
Take for example the molecules that travel freely through the cells and into saliva ducts. These small molecules are used to determine the composition of saliva. Smaller molecules like hormones that are tested in saliva indicate the health and disease status of humans.
So much so that today, saliva analysis are able to predict, diagnose, and prevent many health issues.
When we say that saliva has often been taken for granted, it is not the case in traditional Chinese medicine. In fact, for over 2,000 years, saliva has been used in traditional Chinese medicine that considers saliva and blood as “brothers”, using the thickness, smell and taste of saliva to look for symptoms of diseases.
Since 1898, saliva has been utilized in Western medicine to study the influence of alcoholic drinks on digestion and secretion. The measurement of total organic constituents, salts, and chlorine in saliva became routinely.
By the late 19th century, researchers knew about the role of saliva in digestion. Studies in the early 20th century had shown some evidence of saliva’s role in the diet.
The role of saliva in medicine has expanded through highly sensitive assays such as mass spectrometry, microarray, nano-scale sensors, and reverse transcription polymerase chain reaction or RT-PCR – all of which can measure proteins and nucleic acids with minimal sample requirement in a short period of time.
RT-PCR became well-known and commonplace during the pandemic because it was comparatively easy to use to test for the presence of the COVID virus, producing results (positive or negative) within a relatively short period of time. Indeed, it was during the pandemic that swab tests involved saliva as well.
Saliva tests cannot replace blood tests. However, saliva tests are relatively simple and minimally invasive, cheaper and easier than drawing blood, especially among children and the elderly.
These are among the health issues diagnosed through saliva: acne, allergies, baldness in males, cancer, cardiovascular diseases, cholesterol, cold body temperature, difficulties in giving birth, heart palpitations, inability to absorb calcium, sleep issues, and stress.
Now you know: saliva is not to be taken lightly.
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Dr. Joseph D. Lim, Ed. D., is the former Associate Dean of the College of Dentistry, University of the East; former Dean, College of Dentistry, National University; Past President and Honorary Fellow of the Asian Oral Implant Academy; Honorary Fellow of the Japan College of Oral Implantologists; Honorary Life Member of the Thai Association of Dental Implantology; and Founding Chairman of the Philippine College of Oral Implantologists. For questions on dental health, e-mail jdlim2008@gmail.com or text 0917-8591515.
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Dr. Kenneth Lester Lim, BS-MMG, DDM, MSc-OI, graduated Doctor of Dental Medicine, University of the Philippines, College of Dentistry, Manila, 2011; Bachelor of Science in Marketing Management, De la Salle University, Manila, 2002; and Master of Science (MSc.) in Oral Implantology, Goethe University, Frankfurt, Germany, 2019. He is an Associate Professor; Fellow, International Congress of Oral Implantologists; Member, American Academy of Implant Dentistry and Fellow, Philippine College of Oral Implantologists. For questions on dental health, e-mail limdentalcenter@gmail.com./PN
