1 00:00:01,840 --> 00:00:07,640 Speaker 1: Welcome to brainstuff, a production of iHeartRadio, Hey, rain stuff, 2 00:00:07,680 --> 00:00:13,399 Speaker 1: Laura wollabo'm here. Saliva It's not the kind of thing 3 00:00:13,440 --> 00:00:16,720 Speaker 1: that comes to mind often. Sure, you might notice it 4 00:00:16,800 --> 00:00:20,160 Speaker 1: when you smell the smoke coming off of barbecue, or 5 00:00:20,400 --> 00:00:22,759 Speaker 1: the lack of it when you're about to give a presentation, 6 00:00:24,040 --> 00:00:28,600 Speaker 1: but a seemingly inconsequential thing like spit actually plays an 7 00:00:28,600 --> 00:00:31,040 Speaker 1: important role in our health and in the way that 8 00:00:31,080 --> 00:00:36,920 Speaker 1: our food tastes. Saliva is ninety nine percent water. The 9 00:00:36,960 --> 00:00:40,320 Speaker 1: remaining one percent is made up of well lots of stuff, 10 00:00:40,760 --> 00:00:46,560 Speaker 1: including digestive enzymes, uric acid, electrolytes, mucous forming proteins, and cholesterol. 11 00:00:47,520 --> 00:00:50,600 Speaker 1: It's also home to more than seven hundred types of microbes, 12 00:00:50,640 --> 00:00:55,680 Speaker 1: including bacteria and fungi. The actual makeup of our spit 13 00:00:55,840 --> 00:00:59,640 Speaker 1: varies from person to person, and each person's saliva fluctuates 14 00:00:59,680 --> 00:01:03,800 Speaker 1: due to factors like age, hormonal influences, and various stimuli. 15 00:01:05,640 --> 00:01:08,640 Speaker 1: As is the case with mucus, our bodies are constantly 16 00:01:08,720 --> 00:01:12,039 Speaker 1: producing saliva. Throughout the course of a day, your body 17 00:01:12,160 --> 00:01:14,559 Speaker 1: churns out about two to four pints of it. That's 18 00:01:14,600 --> 00:01:18,280 Speaker 1: one to two liters. Most of that sliva production occurs 19 00:01:18,280 --> 00:01:20,720 Speaker 1: in the afternoon and tapers off at night when we 20 00:01:20,800 --> 00:01:24,800 Speaker 1: tuck into bed. We don't completely stop salivating when we sleep, 21 00:01:25,040 --> 00:01:28,000 Speaker 1: which explains why some side or belly sleepers wake to 22 00:01:28,000 --> 00:01:32,320 Speaker 1: discover that they've drooled on their pillow. Saliva is produced 23 00:01:32,319 --> 00:01:34,840 Speaker 1: in these salivary glands, which are found in the tissues 24 00:01:34,880 --> 00:01:37,720 Speaker 1: of our mouth. These glands are made up of clusters 25 00:01:37,760 --> 00:01:40,600 Speaker 1: of cells that secrete saliva through a series of collecting 26 00:01:40,680 --> 00:01:44,720 Speaker 1: ducks out into the mouth. There are three major pairs 27 00:01:44,760 --> 00:01:49,280 Speaker 1: of salivary glands. The parotid glands are the largest. They're 28 00:01:49,320 --> 00:01:51,560 Speaker 1: located on both sides of your face in front of 29 00:01:51,560 --> 00:01:54,960 Speaker 1: your ears. Each one produces about ten percent of your 30 00:01:54,960 --> 00:01:59,520 Speaker 1: mouth saliva. The submandipular glands are the second largest. They're 31 00:01:59,520 --> 00:02:03,600 Speaker 1: located under the jawbone, and the smallest are the sublingual glands. 32 00:02:03,960 --> 00:02:06,640 Speaker 1: These almond shaped glands lie on the floor of the mouth, 33 00:02:06,880 --> 00:02:12,200 Speaker 1: underneath the tongue. There are also smaller clusters of salivary 34 00:02:12,200 --> 00:02:16,280 Speaker 1: glands in your upper digestive tract and esophagus. These secrete 35 00:02:16,320 --> 00:02:22,440 Speaker 1: sliva with special enzymes that aid in digestion before the article. 36 00:02:22,440 --> 00:02:24,800 Speaker 1: This episode is based on How Stuff Works. Spoke via 37 00:02:24,840 --> 00:02:27,960 Speaker 1: email with Guy Carpenter, a professor of oral biology and 38 00:02:28,040 --> 00:02:32,040 Speaker 1: an oral physiologist at King's College in London. He said, 39 00:02:32,639 --> 00:02:35,240 Speaker 1: saliva's rolls cover all the functions of the mouth you 40 00:02:35,240 --> 00:02:40,120 Speaker 1: can think of, including taste, chew, swallows, smell, but aerosol generation, 41 00:02:40,440 --> 00:02:44,160 Speaker 1: a maintenance of mucosal tissue, lubrication of fats, a maintenance 42 00:02:44,160 --> 00:02:50,400 Speaker 1: of oral microbiome, speech, et cetera. That's a mouthful, so 43 00:02:50,520 --> 00:02:52,919 Speaker 1: let's break it down and discuss some of the important 44 00:02:52,919 --> 00:02:58,800 Speaker 1: functions that saliva carries out in our bodies. First off, yes, 45 00:02:59,000 --> 00:03:03,040 Speaker 1: saliva helps you taste food. Your taste buds get all 46 00:03:03,040 --> 00:03:06,240 Speaker 1: the credit, but they'd be practically worthless if not for saliva. 47 00:03:07,040 --> 00:03:09,799 Speaker 1: It's difficult for our taste buds, which lie in deep 48 00:03:09,880 --> 00:03:14,440 Speaker 1: channels across our tongues, to assess dry lumpy aroma compounds 49 00:03:14,520 --> 00:03:19,160 Speaker 1: without saliva. If you're skeptical, you can try this. Dab 50 00:03:19,200 --> 00:03:22,320 Speaker 1: your tongue dry, then place one lump each of rock 51 00:03:22,400 --> 00:03:26,000 Speaker 1: salt and rock sugar on your tongue. It'll be next 52 00:03:26,000 --> 00:03:29,480 Speaker 1: to impossible to differentiate between the two lumps without allowing 53 00:03:29,520 --> 00:03:34,320 Speaker 1: a wave of saliva to wash over them. A paper 54 00:03:34,320 --> 00:03:36,920 Speaker 1: published in the journal Annual Review of Food Science and 55 00:03:36,960 --> 00:03:40,119 Speaker 1: Technology in March of twenty twenty two, coined the term 56 00:03:40,480 --> 00:03:45,920 Speaker 1: food oral processing to describe this phenomenon. Basically, we only 57 00:03:45,960 --> 00:03:48,680 Speaker 1: perceive the flavor of foods if they can reach the 58 00:03:48,720 --> 00:03:52,960 Speaker 1: taste buds. To get there, food molecules must pass through 59 00:03:53,000 --> 00:03:56,760 Speaker 1: and be coated with a thin layer of saliva. We 60 00:03:56,800 --> 00:04:00,200 Speaker 1: aren't actually tasting the food itself, but the mixture the 61 00:04:00,200 --> 00:04:04,320 Speaker 1: food and the saliva. But the composition and the rate 62 00:04:04,360 --> 00:04:07,320 Speaker 1: of flow of saliva is different for every person, so 63 00:04:07,640 --> 00:04:13,520 Speaker 1: scientists don't know the exact science of how it affects food. Interestingly, 64 00:04:13,960 --> 00:04:17,200 Speaker 1: researchers have found that people with different salivary flow rates 65 00:04:17,440 --> 00:04:20,600 Speaker 1: or different levels of mucus in their saliva may have 66 00:04:20,720 --> 00:04:26,039 Speaker 1: different flavor experiences of the same foods. For example, in 67 00:04:26,080 --> 00:04:28,960 Speaker 1: a study published in the journal Food Research International in 68 00:04:28,960 --> 00:04:33,159 Speaker 1: December of twenty nineteen, scientists measured sliva levels and participants 69 00:04:33,240 --> 00:04:35,920 Speaker 1: who agreed to evaluate the taste of wine to which 70 00:04:35,960 --> 00:04:40,279 Speaker 1: fruity flavored compounds had been added. Those who produced more 71 00:04:40,320 --> 00:04:44,560 Speaker 1: saliva tended to score the flavors as more intense. The 72 00:04:44,600 --> 00:04:49,160 Speaker 1: researchers surmised that these participants swallowed more often, which forced 73 00:04:49,160 --> 00:04:52,240 Speaker 1: more aromas into their nasal passages, resulting in a more 74 00:04:52,320 --> 00:04:57,360 Speaker 1: intense tasting experience, which brings us to saliva and the nose. 75 00:04:59,080 --> 00:05:01,880 Speaker 1: The saliva can also affect the aroma of the food 76 00:05:01,920 --> 00:05:05,000 Speaker 1: you eat, which is responsible for the vast majority of 77 00:05:05,040 --> 00:05:09,080 Speaker 1: your perception of flavor as you chew. As some flavor 78 00:05:09,120 --> 00:05:13,280 Speaker 1: molecules dissolve in the saliva, those that don't can waft 79 00:05:13,360 --> 00:05:16,480 Speaker 1: into the nasal cavity and be sensed by the perceptors there. 80 00:05:18,240 --> 00:05:21,120 Speaker 1: Saliva also helps prevent you from choking on your food 81 00:05:21,880 --> 00:05:25,400 Speaker 1: as we choose. Sliva joins in and turns dry, crumbly 82 00:05:25,480 --> 00:05:28,799 Speaker 1: food bits into soft, cohesive lumps that are better able 83 00:05:28,839 --> 00:05:31,640 Speaker 1: to slide down our esophagus and continue their way through 84 00:05:31,680 --> 00:05:35,920 Speaker 1: our digestive tract. It also helps protect our esophagus from 85 00:05:35,960 --> 00:05:40,960 Speaker 1: getting damaged by any rough edged food particles, and saliva 86 00:05:40,960 --> 00:05:44,960 Speaker 1: helps you digest your food too. Remember that smaller cluster 87 00:05:45,040 --> 00:05:48,280 Speaker 1: of salivary glands in the upper digestive tract and esophagus. 88 00:05:49,160 --> 00:05:53,600 Speaker 1: They produce a type of saliva containing digestive enzymes. One 89 00:05:53,760 --> 00:05:56,760 Speaker 1: breaks down starch into sugars so your body can absorb 90 00:05:56,800 --> 00:06:01,479 Speaker 1: it more easily. Another helps break down fats These enzymes 91 00:06:01,520 --> 00:06:06,920 Speaker 1: prepare the food you've swallowed for the stomach. Your saliva 92 00:06:07,040 --> 00:06:10,760 Speaker 1: is also saturated with calcium and phosphate ions that help 93 00:06:10,800 --> 00:06:14,800 Speaker 1: protect the enamel surface of your teeth. Without this concentration 94 00:06:14,920 --> 00:06:17,480 Speaker 1: in your saliva, the enamel on your teeth would start 95 00:06:17,520 --> 00:06:22,640 Speaker 1: to erode. This helps explain nursing bottle syndrome, a condition 96 00:06:22,720 --> 00:06:25,599 Speaker 1: in young children who suck on filled bottles or sippy 97 00:06:25,600 --> 00:06:29,440 Speaker 1: cups for prolonged periods of time. The milk or juice 98 00:06:29,440 --> 00:06:32,159 Speaker 1: can sit on the teeth and especially the top teeth, 99 00:06:32,160 --> 00:06:35,480 Speaker 1: which are less protected by saliva, long enough for bacteria 100 00:06:35,640 --> 00:06:40,039 Speaker 1: to start causing cavities. Saliva also protects from tooth decay 101 00:06:40,200 --> 00:06:47,400 Speaker 1: by helping dilute dietary carbohydrates and neutralizing the acids from plaque. Finally, 102 00:06:47,839 --> 00:06:51,600 Speaker 1: remember how we said your saliva changes due to different influences. 103 00:06:52,480 --> 00:06:55,919 Speaker 1: Your spit is affected by the body's fight or flight response. 104 00:06:56,720 --> 00:07:00,040 Speaker 1: When you experience high stress or anxiety, your body he 105 00:07:00,160 --> 00:07:03,640 Speaker 1: seeks to conserve energy so that you can fight or flee. 106 00:07:04,320 --> 00:07:06,200 Speaker 1: One of the ways the body does this is by 107 00:07:06,200 --> 00:07:11,480 Speaker 1: shutting down your digestive system. That's why when you're feeling stressed, scared, 108 00:07:11,560 --> 00:07:14,600 Speaker 1: or anxious like when you're about to speak publicly. You 109 00:07:14,640 --> 00:07:18,920 Speaker 1: may notice your mouth feels especially parched, and that's why 110 00:07:18,960 --> 00:07:23,800 Speaker 1: speakers often keep water nearby During speeches, presentations, and other performances. 111 00:07:24,280 --> 00:07:28,520 Speaker 1: It's difficult to speak with a dry mouth. Water can help, 112 00:07:28,840 --> 00:07:31,160 Speaker 1: but having an adequate amount of saliva in the mouth 113 00:07:31,360 --> 00:07:35,080 Speaker 1: lubricates the oral tissues, making it easier to talk smoothly. 114 00:07:39,920 --> 00:07:42,360 Speaker 1: Today's episode is based on the article what is the 115 00:07:42,440 --> 00:07:44,720 Speaker 1: liva and how does it change the Taste of food? 116 00:07:44,800 --> 00:07:47,560 Speaker 1: On how stuffworks dot com written by Jennifer Walker. Journey 117 00:07:48,080 --> 00:07:50,600 Speaker 1: brain Stuff is production of iHeartRadio in partnership with how 118 00:07:50,640 --> 00:07:52,960 Speaker 1: Stuffworks dot Com, and it is produced by Tyler Lang. 119 00:07:53,600 --> 00:07:56,600 Speaker 1: For more podcasts my heart Radio, visit the iHeartRadio app, 120 00:07:56,760 --> 00:08:05,480 Speaker 1: Apple Podcasts, or wherever you listen to your favorite shows.