Sugar, Sugar. How Come You Taste So Good?

I force myself not to look away from the procedure. The attending’s hand is shaking terribly. No one in the room says anything, but it’s obvious to everyone that he is nervous and doesn’t perform many procedures. If he were a resident physician, someone would have stepped in by now and offered calming words or guidance. But this is an attending physician, and it would seem condescending for me, a medical student, to offer assistance. I scan the eyes of the others in the room, and everyone is staring intently at the infant, slightly apprehensive.

This infant is only a few days old, but he has been having trouble breast feeding. We noticed on rounds yesterday that the lingual frenulum of his tongue (the tissue in the middle of the underside of the tongue that connects the tongue to the floor of the mouth) was attached too close to the tip of the tongue. Those not in the healthcare field might call this tongue-tied. Our previous attending physician told us that being tongue tied can significantly restrict the movement of the tongue and affect breast feeding and swallowing. She decided to schedule the infant for a frenulectomy, a procedure to snip a small portion of the frenulum, and allow greater movement of the tongue for improved breast feeding.

That attending physician had an emergency today, and another doctor is covering for her. So far, it’s not going well. We’ve been watching for sixty seconds while he tries with difficulty to position the tongue in one hand and the scissors in the other.

“Would it help if I hold him for you?” Sue, one of the second year pediatrician residents, asks the attending. I breathe an internal sigh of relief. Sue is confident, competent, and she has a steady hand.

The attending looks nervously around the room, and recognizes the palpable tension.

“Sure” he nods.

Sue slides a small, notched piece of plastic under the baby’s tongue, in order to protect the underside of the tongue from the scissors. As she holds the baby firmly, she coos to help keep the baby calm, and we notice the baby’s posture relax.

The attending’s hand still shakes, but Sue ensures the baby’s mouth and tongue remain in position.

Snip…snip…and it’s done. Just a few millimeters are cut, and there’s no significant bleeding. But the shrill cries from the baby’s mouth let us know that he didn’t enjoy the procedure. Sue pulls the baby close in to her chest and rocks him gently. But despite Sue’s best efforts, the baby continues his piercing cry.

“Fill, hand me one of those vials,” Sue says as she points to the countertop behind me.

I walk a few steps toward the back of the room and scan the countertop. The plastic vials are in a square metal tray next to the sink. I grab a vial and snip a small portion of the plastic from the top before handing it to Sue. She squeezes it into the infant’s mouth and he stops crying instantly. His mouth moves in a sucking manner, and just like that, it seems as though he forgets the pain entirely. After a few minutes, Sue gently hands the baby to one of the pediatric nurses.

When I first saw the vials used with circumcisions last week, I thought the contents included some proprietary concoction of a fast acting anesthetic or analgesic. It contained only 1 milliliter of fluid, but it worked miracles. And the infants always stopped crying. Needless to say, the procedure room kept a robust supply of these vials in stock.

“Sue, what is that stuff?” I asked her.

“The fluid in the vial? Taste it!” She grins as she nods towards the metal tray.

“Are you serious? Isn’t my tongue going to go numb or something?” I asked.

“Yeah, and if you drink too much, you’ll turn purple!” She jokes as she opens a vial and squeezes a drop into her mouth. “See? It’s safe”.

Her face doesn’t wince at all, so I figure it must be safe and taste okay. It certainly can’t taste as awful as the metronidazole liquid (an antibiotic) the pharmacist let us taste during a lecture last week.

I grab another vial from the metal tray, snip the top off and squeeze it into my mouth… Whoa! To my surprise, it actually tastes really good.

“Whatever this is, it sure tastes sweet.” I comment.

“Well it should, Fill. It’s just sugar and water,” replies Sue.

“That’s it?! Just sugar and water?” I asked in disbelief.

“Yup, that’s it.”

Humans love the taste of sugar, more than any other food. Infants, who have never tasted food before, inherently LOVE sugar, to the point where they temporarily forget about everything else (including pain) while they consume it. This natural predisposition toward the love of sugar doesn’t weaken as infants grow. As more sugar is consumed, the body becomes accustomed to the way it makes the body feel, and the body has multiple mechanisms of creating cravings to obtain more sugar. This means that if people base their food choices on taste alone, many will consume unhealthy, large volumes of high sugar foods.

Why is the human body naturally driven to crave sugar?

The human brain runs almost exclusively on glucose, one of the simplest forms of sugar. And despite the fact that the brain’s weight only accounts for about 1-2% of our total body weight, it consumes around 60% of the glucose that our whole body uses at rest. Unlike muscle tissue, the brain does not have a way to store its own supply of glucose, so it relies on the body to provide a continuous supply of glucose through blood. Many foods we consume eventually break down into glucose to provide this source of fuel for the brain. So what is it about sugar, specifically table sugar (glucose combined with another sugar called fructose), that makes humans crave it more than whole grains, beans, fruits and other foods?

Sweet flavor is the most important factor that drives sugar cravings. The sweetness of table sugar activates ‘sweet taste receptors’ that are located on our tongues and in other portions of our body, including our intestines, nose and portions of our lungs. These receptors provide reward signals to our brain through at least three different pathways, including the opioid, endocannabinoid and mesolimbic dopaminergic systems. Although this example grossly oversimplifies things, imagine that a sweet taste receptor could activate the same feelings of pleasure as a synthetic opioid, marijuana and positive verbal reinforcement all at once. All of these systems together create an intense feeling of pleasure, and have the potential to create dependence and addiction.

There are other factors that drive cravings for table sugar as well. The body releases reward signals from the gut in response to the high caloric density of table sugar. In addition, if someone regularly eats table sugar, the body can develop bacteria in the gut that thrive on table sugar and can release substances that induce cravings or feelings of pleasure.

“Fill, so far this sounds like a good thing. If the brain mainly runs on glucose, and table sugar contains glucose, why is it bad for the body to create cravings and rewards for consuming table sugar?”

Good question. By itself, this process isn’t bad. In fact, some of the healthiest foods that we eat taste sweet because of natural sugars and are eventually broken down into glucose. But the focus today is on added sugar, not natural sugars. Table sugar is one common form of added sugar, but there are hundreds of different forms available. Added sugar, as a group, has many features that make it unhealthy.

  1. Added sugar causes blood sugar surges

Since added sugar is stripped of all of its fiber, it is rapidly absorbed into the blood stream and causes blood sugar surges, which is unhealthy for the human body. Although our brain needs a constant supply of glucose, it doesn’t need glucose surges, even for our highest levels of brain function. The body is fully capable of independently maintaining a consistent and appropriate supply of glucose to the brain without high surges of blood sugar, even long after we have had our last meal, mainly by generation of glucose through the liver. In addition, healthy carbohydrates, like whole grains and fruits, can provide a steady supply of glucose through the gut without spiking blood sugars.

  1. Added sugar does not make you feel full

The two types of nutrients that elicit the greatest feeling of satiety, or fullness, are protein and fiber. Added sugar contains neither of these nutrients. So if you eat a food or drink a beverage that is high in added sugar and low in fiber or protein, you’ll be hungry again relatively soon and ultimately eat more calories to satisfy the returning hunger.

  1. Added sugar does not contain phytonutrients, vitamins or minerals

Added sugar is, by definition, a processed sugar. The original ingredient for the added sugar may start as a healthy plant, but the processing strips most of its nutritional value away. Let’s look at the sugarcane plant as an example. When sugarcane is harvested, it has fiber, phytonutrients, vitamins and minerals. When it undergoes processing, the sugarcane plant is milled into smaller parts before the juice is squeezed out of it. The nutritious fiber of the sugarcane is then discarded for fuel, fertilizer or animal feed. Since many of the vitamins and minerals in the sugarcane plant are contained in the fiber of the plant, these are lost when the fiber is separated from the juice. Although the sugarcane juice still contains many beneficial phytonutrients, mainly phenolic acids and flavones, these are lost throughout the remaining processing steps, which include purification with heat and calcified water (also known as lime), mechanical separation via centrifuge, crystallization, bleaching and vacuum drying. Along the way, all of the beneficial phytonutrients are destroyed.

“So Fill, added sugar is unhealthy and our body doesn’t need it, but it makes us feel good without making us feel full, so it’s easy to eat more of it. This sounds like a setup for disaster.”

You’re right, it is. And since added sugar is widely available and extremely inexpensive, it leads to the following vicious cycle…

-A food industry company adds a large quantity of added sugar to a food product

-People enjoy the taste of the product and purchase it repeatedly

-The company recognizes increased sales and revenue of that food product

-The company creates more products with added sugar to maintain higher revenue

-People continue buying more of their products because they taste good

-Stockholders become very happy

-The board of directors encourages high added sugar content foods because it makes money

-Some consumers recognize that a food product is unhealthy because of the added sugar and stop purchasing it

-The food industry company recognizes decreased sales and starts over, this time sneaking added sugar into ‘healthy’ foods to increase revenue

This cycle repeats itself and before you know it, almost every processed food product in a grocery store has added sugar in it.

One of my favorite food related books, Salt Sugar Fat by Michael Moss, provides an entertaining and nostalgic history of some of our nation’s most beloved grocery brands (Lunchables, Tang, Oreos, Pringles, the whole cereal industry) and how the mother companies deliberately and precisely alter the foods to make them irresistible. The companies perform taste testing on children and adults, studying varying amounts of added sugar in the same product, increasing added sugar to the point of maximal satisfaction and return on investment, sometimes as high as 50-70% of the food product! They have huge research divisions that study human behavior and exploit our inherent desire for sugar in order to make the company more profitable.

In their efforts to create profits and maintain booming business, food manufacturers have made many incredibly unhealthy foods. Despite consumers knowing that many of these foods are unhealthy, they continue buying them because they taste good. And as long as consumers continue purchasing these foods, manufacturers will continue producing them. If one manufacturer attempts to stop making foods high in added sugar, another will take its place to fill consumer demand. In other words, as a nation of consumers, we literally can’t stop ourselves from buying foods with added sugar. This process has spiraled so far out of control and has led to such a profound increase in obesity and its associated healthcare costs, that the World Health Organization now recommends that governments levy a sugar tax to curb consumer consumption of added sugar. The freedom to eat whatever one wants may soon come with a sugar tax, soda tax, or a different health insurance premium. Recently, such taxes have been successfully implemented in a few cities of the United States. But like any legislature, these taxes are vulnerable to the controversy and manipulation that frequently accompany political endeavors.

The less controversial aspect of government regulation of added sugars is in regards to product labeling. The FDA uses the nutrition label as a mechanism for the consumer to obtain objective and discrete nutritional information devoid of marketing bias. As a consumer, this is one of our most valuable nutritional resources. But food manufacturers attempt to confuse consumers even on the nutritional label. So let’s explore added sugar on a nutritional label…

Added sugar is disguised under a variety of names. These include the three chemical names for the simplest forms of sugar:

-glucose (also known as dextrose)



Added sugars might also be labelled using chemical names for two simple sugar molecules bonded together:

-sucrose (glucose and fructose)

-maltose (two glucose molecules)

-lactose (glucose and galactose)

Also, added sugar may have various names depending on its water content or according to its level of processing

-Juice (sugar dissolved in water)

-Syrup (sugar with much of the water content evaporated away, forming a thicker fluid)

-Molasses (the more viscous portion of syrup separated just prior to undergoing crystallization)

-Table sugar (the form of sugar that has undergone crystallization and further refining)

-Brown sugar (a mixture of molasses and table sugar)

In general, any ingredient that includes the word sugar or syrup or juice is a sugar derivative and should be treated nutritionally the same as table sugar. For example, granola bars are notorious for trying to trick the consumer into thinking a sugar ingredient is healthy by disguising it, like using an ingredient such as organic brown rice syrup. It’s made from brown rice, not white rice, and it’s organic. So it’s probably healthier than other added sugars, right? The syrup produced from organic brown rice is stripped of all its healthy nutrients, just like added sugar made from sugarcane. In this respect, remember that the end product is more important than the initial ingredient that the product was made from. Regardless of the starting ingredient, it goes through the same process of extracting the juice/syrup from the plant and further processing which strips away the nutritious fiber and many of the vitamins, minerals and phytonutrients of the plant.

The FDA is aware of the struggle consumers face to decipher added sugar content on food labels. Fortunately, they have proposed a change to food labels that will force manufacturers to include total sugars, added sugars, and percent daily value of added sugars on the nutrition label. This is slated to take effect on July 26, 2018 for all major food manufacturers, but there is pushback that may delay the FDA change date to Jan 1, 2020. Some food manufacturers, typically ones that produce healthier foods, have already implemented these changes before the required date. You may have noticed different nutrition labels on some foods in your pantry. The percent daily value of added sugars will make it very simple for people to pick out how strikingly unhealthy some foods are. I’ve included a link below to demonstrate a comparison of the old and new label.

In summary, added sugar, in any of its various forms, is one of the most unhealthy foods in the consumer market. It is a source of calories devoid of any other nutritional benefit. It is best to think of added sugar as raw, rapidly absorbed fuel. It may be useful for an athlete to quickly replete glucose stores in between intense sporting events, but it isn’t necessary for the majority of those who perform moderate intensity exercise or high intensity exercise for a short duration. For those who don’t exercise, it will quickly be stored as fat.

It’s important for you as the consumer to be aware of the impact of added sugar on health, the body’s strong inherent desire for added sugar, and the way the food industry has manipulated this desire for financial gain. Millions of consumers have unknowingly acquired various chronic diseases as a result of poor nutrition, with added sugar playing a large role. Regardless of fault, this has placed an enormous burden on the healthcare industry, taxpayers and has greatly driven up healthcare costs, which affects you.

Even a few minor alterations in diet can lead to relatively rapid improvements in health. I see it happen in motivated patients every day. It takes a lot of discipline, and requires us to re-evaluate the foods we grew up with and loved. Don’t let television ads, celebrities or even your prior conceptions of food cloud the facts. Read the nutrition label and decide for yourself. But remember that ultimately food has to taste good or you won’t eat it again. Use the body’s inherent love for sugar to your advantage. For example, in small amounts, freshly squeezed lime juice, honey, wine or a few chocolate chips can go a long way to make a healthy but bland food taste better. Focus on using sugars to make healthy foods taste good, and feel good about doing it. Otherwise, make small, specific changes to eat less added sugar 3 months from now than you eat today and you’ll be headed in the right direction. In general, slow dietary changes are more successful and help to avoid issues with cravings and rebound binge eating. Give yourself time, know that you will have setbacks, and you’ll be surprised where your nutrition and health could be in a year.

How It’s Made: Sugar

-Featured Image by Joseph Gonzalez on Unsplash.

Lee AA, Owyang C. Sugars, Sweet Taste Receptors, and Brain Responses. Nutrients. 2017 Jun 24;9(7). pii: E653. doi: 10.3390/nu9070653. Review. PubMed PMID: 28672790; PubMed Central PMCID: PMC5537773.

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