saliva – Dr. Danenberg

Dr. Al Danenberg ● Nutritional Periodontist

June 3, 2019

Overall, the human body is made up of approximately 60% water.[1] The lungs are about 83% water; the muscles and kidneys are about 79%; the brain and heart are about 73%; the skin is about 64%; and the bones are about 31%. Saliva, which is very wet, is about 98% water. But the 2% of saliva that is not water possesses some very remarkable properties. Saliva reportedly is a miracle fluid within our body.

Almost no one thinks about his or her saliva. Practically everybody takes it for granted. Saliva has many functions in addition to its diagnostic capabilities. However, if salivary flow is compromised or abruptly stopped, the health consequences could be significant.

Starting in the Mouth[2]

Obviously, saliva helps to maintain a moist mouth. A wet mouth is less susceptible to mechanical abrasion from foods. Saliva functions as a lubricant allowing efficient chewing of food, swallowing, and speaking. It also helps remove excess micro-organisms and dead cells by swallowing.

Chemicals in food can dissolve in saliva which allows the taste buds to function properly. Amylase, an enzyme in the saliva, helps to begin the digestion of starches in the mouth. In addition, saliva acts as a buffer to neutralize acids in the oral cavity.

The protective benefits of saliva on the teeth are very important. Saliva helps to form the enamel pellicle. This pellicle attaches to the tooth surface near the gum line. The saliva and the pellicle begin to support the growth of healthy dental plaque. Saliva supersaturates healthy dental plaque with (1) minerals to remineralize tooth surfaces and (2) buffers to maintain a healthy pH level at the tooth surface. Dental plaque becomes unhealthy when the immune system is compromised, which then encourages pathological species of bacteria to overgrow in dental plaque.

There are over 700 species of microbes in the mouth, which in health are in a state of balance. Interestingly, saliva contains many antibacterial, antiviral and antifungal agents which modulate this garden of bacteria. Saliva also assists healing of oral wounds.

All in all, saliva has many functions which are required for a healthy mouth.[3] It’s a real miracle fluid.

Dry Mouth

Loss of salivary gland function can result in a dry mouth (xerostomia). Lack of saliva contributes to bad breath, gum disease, tooth decay, and improper healing properties. Unfortunately, head and neck radiation therapy as well as chemotherapy, which are used to treat specific types of cancer, may cause xerostomia. Some other factors that can affect the health of saliva and cause dry mouth are gut dysbiosis, emotional stress, local and systemic acute infections, and certain medications. Also, some congenital abnormalities, Sjögren’s syndrome, and HIV/AIDS can cause dry mouth.

Saliva and Blood Pressure

Saliva contains biologically active nitrates, which have been stored in the salivary glands. Eventually, these nitrates are transformed into nitric oxide. Some of the functions of nitric oxide are to reduce blood pressure, reduce the risk of cardiovascular disease, improve athletic performance, and improve gum health.[4]

Here is how nitrate becomes nitric oxide:

After you eat leafy greens that contain natural nitrates, your body absorbs these nitrates through your upper GI tract. About 25% of these nitrates are concentrated into your salivary glands. From the salivary glands, nitrates enter the saliva. The normal anaerobic bacteria on your tongue change the nitrates in the saliva into nitrites. Then, you swallow the nitrites. Nitrites then move throughout your body and are further changed into nitric oxide.

In 2017, Nathan S. Bryan and coauthors[5] reviewed the current research describing the importance of saliva and oral bacteria on the nitrate/nitrite/nitric-oxide pathway.

A Diagnostic Tool[6]^,[7]

Another benefit of saliva is its excellent diagnostic ability.

The collection of saliva is simpler, less painful, and cheaper than blood draws. Another important advantage of saliva is the fact that it may be retrieved several times a day, which allows a simpler way to obtain repeated tests. Blood draws are impractical if repeated tests over a short timeframe are desired.

Furthermore, saliva has very high durability. The non-water elements in saliva contain numerous organic and inorganic substances, which can be tested as biological markers just as in blood samples. For these reasons, saliva may be ideal for detecting and monitoring various diseases.

Summary

Saliva is critical on many fronts. Staying hydrated properly and eating nutrient-dense foods are necessary to provide the basic elements required for healthy salivary glands and healthy saliva.

[1] https://www.usgs.gov/special-topic/water-science-school/science/water-you-water-and-human-body?qt-science_center_objects=0#qt-science_center_objects

[2] https://www.ncbi.nlm.nih.gov/pubmed/?term=10.1016%2Fj.archoralbio.2015.03.004

[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3312700/

[4] https://www.ncbi.nlm.nih.gov/pubmed/27872324

[5] https://www.ncbi.nlm.nih.gov/pubmed/?term=Oral+Microbiome+and+Nitric+Oxide%3A+the+Missing+Link+in+the+Management+of+Blood+Pressure

[6] https://www.ncbi.nlm.nih.gov/pubmed/?term=10.1016%2Fj.advms.2017.11.002

[7] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5113094/