Mary Roach, the author of 2003’s "Stiff," recently published a book that is more to my taste: "Gulp: Adventures on the Alimentary Canal." The book discusses little known facts, quirky historical stories, and current research on food-tasting, saliva production, digestion, and it even delves into the bowels of… our bowels.
The chapter that I really sunk my teeth into discussed saliva. Having participated in salivary research under the oral biologist, Dr. Libuse Bobek at the State University ofNew York at Buffalo, I thought I already knew a great deal about saliva, but I had to swallow my pride as I learned a great deal more. Don't be turned off by this topic folks; saliva is nothing to spit at!
The saliva of babies for instance contains more of the enzyme (lipase) necessary to break down fat, so they can digest milk easier. As the baby grows and is introduced to new foods, the enzyme amylase becomes predominant (to break down carbs). This enzyme in our saliva is why a potato chip will rapidly dissolve into mush after only a couple crunches in our mouths.
The author goes further on the discussion of enzymes, making an interesting connection between our saliva and laundry detergent. The enzymes used in detergents to clean food stains from our clothes are in fact digestive enzymes (amylase, protease and lipase). Don't worry though, these enzymes are not derived from an army of people spitting into jugs at the Tide and Wisk factories (they're extracted from fungi infused with the genes to produce these enzymes).
Another interesting tid-bit that Mary Roach shares is the fact that smells and scents do not stimulate saliva. In other words, regardless if you smell a batch of freshly baked chocolate cookies, or take a whiff of that pepperoni pizza you just picked up at Pepe's, your mouth won't produce any more saliva than it would normally produce. So, it turns out that the cartoon clip showing a hungry wolf salivating when smelling the 3 little pigs is as equally unrealistic as the clothing being worn by these talking animals!
Finally, Erika Silletti, the scientist followed and interviewed by author Mary Roach, makes reference to the area of research that I studied; namely, that saliva has antimicrobial properties in the form of proteins called mucins. Even when the proteins of the spit are broken down, the small protein pieces (peptides) that remain behind have equal if not better germ-killing attributes. As a specific example, proteins are normally dozens to hundreds of amino acids in length, whereas the very effective germ killer MUC7-12mer I studied was only 12 amino acids in length. Obviously even though our mouths are known to be filled with millions of germs of multiple varieties, our saliva has the ability to regulate and control what thrives and what dies in the oral environment!
So, do yourself a flavor (oops, I meant 'favor') and pick up a copy of this entertaining and educational book.
(Of course if you think books are just dead-weight, maybe Mary Roach's book "Stiff: The Curious Lives of Human Cadavers" is more up your alley)