Sweet like sugar or a deadly deceit?
How artificial sweeteners make the problems they were supposed to solve, worse.
For decades it has been claimed that sugar causes multiple medical problems, particularly obesity and type 2 diabetes. Others have raised similar concerns about artificial sweeteners. Although there is good evidence supporting these claims, like many strong claims, there is reason to be skeptical. Controlled studies are difficult to come by so that leaves us with only “some truth to be had”.
Before we discovered sugar or had a lick of honey, the sweetest food we ever tasted was our mother’s milk. Human breast milk is rich in proteins, carbohydrates, and fats along with the majority of essential minerals a growing baby needs. It also contains cannabinoid compounds which stimulate appetite and calms the baby while it feeds. After weaning, the next sweetest thing we are likely to encounter is starchy tubers like carrots or honeycomb. It wasn’t until the the 19th and 20th century, when we saw the sudden global availability of sweetened drinks and sugary snacks. It was during this period that we began to see a rise in obesity and type 2 diabetes.
Sugar, a disaccharide, is comprised of a glucose and fructose molecule. Thus, sugar provides us with the essential nutrient, glucose, necessary for the function of every cell in our body. Health benefits are received when glucose and fructose are obtain from whole foods including fruits, vegetables, and starches, along with other nutrients. When we have excess glucose, our blood sugar (glucose) levels increase and the excess glucose is stored as glycogen, in our muscle and liver cells, and as fat in our adipose tissue. Added sugar, on the other hand, confers no additional health benefits nor does it provide other essential nutrients.
We eat candy because it tastes sweet and triggers the reward system in our brain causing a release of natural opiates that stimulate our appetite for more sucrose. This helps us understand why obesity is so difficult to treat. The reward response is so strong that it can be difficult to overcome. This fact was illustrated most tragically by a drug, Rimonabant, that was designed to block a crucial part of the reward system.
Rimonabant was developed as an anti-obesity drug. It was designed to target the endocannabinoid system (ECS) and block the receptor that’s associated with the primary effects of THC, including appetite stimulation. The logic was that by blocking this receptor, appetite would be suppressed and the individual would lose weight. It turns out, that by inhibiting the sense of reward we get when we eat, we also inhibit the sense of reward we get from everything else. Twenty percent of the patients using Rimonabant experienced major depression and there were several suicides. It seems that blocking the reward system makes life not worth living.
Dopamine is another key chemical involved in the rewards system. Dopamine is all about motivation and attention. It is what helps us decide what to focus on, what to do, and makes us anticipate and feel satisfied by our accomplishments. The reward for eating a good meal is not only no longer feeling hungry, it is also the feeling of satisfaction for having eaten. It’s like our body is telling us, “thanks for the meal, now don’t forget next time you’re feeling hungry, food cures hunger.” Without that reinforcement, it seems, we may simply not eat the next time we feel hungry and ultimately starve to death.
Dopamine rounds out the reward response reassuring us that actions are good and worth doing. If our dopamine system is not working properly we may lack that reinforcement and forget how rewarding certain behaviors are. Certain drugs, like Adderall, work by mimicking the activity of dopamine in the reward centers of our brain. This means that everything we do will feel more significant and ultimately more rewarding. Dopamine, like Adderall, makes thing interesting and therefore we are more likely to want to do them. But you don’t need to get a prescription to boost motivation.
Defining “sugars” can be complicated. Carbohydrates are comprised of 6 carbon molecules called hexoses. Each carbon is ‘hydrated’ with a water molecule. There are 3 categories of carbohydrates that have nutritional benefit. They include: (1) monosaccharides (glucose, fructose, and galactose), (2) disaccharides (sucrose, lactose, and maltose), and (3) polysaccharides (glycogen, starch, and cellulose). Sugars, often called simple sugars, refer to the disaccharides like sucrose and can come from a variety of sources. They include refined sugars, which can be made from natural sources like cane or synthesized from grain or beet crops. Sweetness can also be added to food by using ingredients like raisins, apple juice, or honey. Regardless the source or initial form, all sugars are converted into glucose, fructose, and galactose during the process of digestion. Remember, glucose is the primary fuel for all our cells.
Sweet like sugar, but not sugar. Artificial sweeteners trick our brains into thinking we are consuming sugar without actually consuming it. This is because “sweetness” doesn’t just come from sugar. There are hundreds of organic, synthetic, and inorganic compounds that taste sweet just like sugar. The sweetness we taste depends on the degree to which a molecule interacts with the receptors on our tongue associated with sweetness. The stronger the interaction, the sweeter the perceived taste. One popular natural sweetener is Stevia. Stevia is made from a plant native to Brazil and Paraguay and has been used for centuries as a sweetener. It is roughly 300 times sweeter than sugar and is not metabolized by the body.
Recently, questions have been raised about whether artificial sweeteners promote diabetes and obesity. Non-sugar sweeteners often contain fewer carbohydrates and are less likely to cause a spike in blood sugar levels. For this reason they are often recommended to individuals trying to lose weight or reduce damage caused by metabolic disorders, such as type 2 diabetes.
Many studies support those recommendations, while others suggest that artificial sweeteners might actually lead to weight gain and a higher risk of metabolic disorders. One such study, from the Washington University School of Medicine, found that the artificial sweetener sucralose was linked to an increased glucose and insulin levels. Sucralose is the selective chlorination of sucrose that makes it undigestible and thus non-caloric. It is marketed as Splenda and is about 320 to 1,000 times sweeter than sucrose and twice as sweet as saccharin.
In another study, researchers investigated how artificial sweeteners affected the metabolism of mice. What they observed was that mice who were fed a combination of sugar and an artificial sweetener developed glucose intolerance while those who were fed sugar alone, did not. They proposed that the effects were being caused by changes to gut bacteria affected by the consumption of artificial sweeteners. These changes had been previously associated with type 2 diabetes in humans.
This research suggests that artificial sweeteners may be promoting the exact problems they were intended to fight. An ongoing study intended to assess the effect of long-term consumption of artificial sweeteners on humans has revealed some startling associations. The long-term consumption of artificial sweeteners has been associated with increased weight, increased waist-to-hip ratio (an indicator obesity), and higher fasting blood glucose levels.
So the next time you feel like indulging your sweet-tooth think with a artificially sweetened beverage, think twice and consider limiting your overall consumption of sweet foods.