Many people choose artificial or alternative sweeteners because they believe these products are safer and healthier than normal sugar.
Sweeteners such as aspartame, sucralose, and sugar alcohols are often added to “low-calorie” or “sugar-free” foods and drinks. They are found in diet sodas, protein bars, chewing gum, candy, and even some medicines.
For years, these sweeteners have been promoted as a better option for people who want to lose weight or control their blood sugar. However, new research suggests that some of these substitutes may not be as harmless as once thought.
A recent study published in the journal Science Signaling looked closely at sorbitol, a type of sugar alcohol. Sorbitol is commonly used to sweeten low-calorie foods, and it is also found naturally in some fruits such as apples, pears, and stone fruits.
The study was led by Professor Gary Patti and his team at Washington University in St. Louis. Their work is part of a growing body of research showing that certain types of sugar and sugar-like substances can harm the body, especially the liver.
The liver plays a very important role in the body. It helps process nutrients, remove toxins, and manage energy storage. When too much sugar enters the body, the liver has to work harder to handle it. In previous studies, Patti’s team showed that fructose, a type of sugar found in many sweetened foods and drinks, can damage the liver.
It can also be used by cancer cells to grow more quickly. Fructose has been linked to a condition called steatotic liver disease, also known as fatty liver disease. This condition now affects almost one in three adults around the world.
What surprised the researchers in this new study was that sorbitol can easily turn into fructose inside the body. In simple terms, sorbitol is only one chemical step away from becoming fructose. This means that eating large amounts of sorbitol could lead to the same harmful effects that are already known to come from too much fructose.
To understand how this happens, the researchers used zebrafish in their experiments. Zebrafish are often used in scientific studies because their bodies share some similar processes with humans. The researchers found that sorbitol can be produced naturally in the gut after a person eats.
When glucose levels become high after a meal, certain enzymes in the gut can change that glucose into sorbitol. This does not only happen in people with diabetes. Even healthy people can produce sorbitol in their gut after eating a meal that is high in sugar or carbohydrates.
Once sorbitol is formed in the gut, two different things can happen. If the person has the right type of gut bacteria, those bacteria can break down the sorbitol into harmless substances that are safely removed from the body. In this case, sorbitol does not cause much trouble.
But if the person does not have enough of these helpful bacteria, or if there is simply too much sorbitol in the gut, the body cannot clear it properly. When this happens, the sorbitol travels to the liver. There, it can be converted into a form of fructose and begin to cause damage, just like ordinary sugar does.
This is where diet becomes very important. Small amounts of sorbitol, such as those found in fruit, are usually not a problem for a healthy person. The gut bacteria can normally deal with it. The problem arises when large amounts of sorbitol are consumed through processed foods, sugar-free products, and certain sweeteners.
In addition, when a person eats a lot of sugar and refined carbohydrates, the body may produce even more sorbitol from glucose. This double effect can overload the gut’s ability to break it down.
Even people who have the “good” bacteria that help remove sorbitol can run into trouble if they consume too much of it. The bacteria simply cannot keep up. This means that the idea of unlimited “sugar-free” products is misleading. Eating large quantities of these products may still put stress on the liver and other tissues in the body.
In fact, Patti was surprised to discover that one of his own favorite protein bars contained a large amount of sorbitol. This reveals how common this ingredient has become in everyday foods, even in products that are marketed as healthy.
Further studies are still needed to fully understand how gut bacteria break down sorbitol and how this process can be supported. However, one important message from this research is already clear. Sugar alcohols, also called polyols, should not automatically be seen as safe and harmless.
The researchers found that when animals were given sorbitol, it could later be found in different organs throughout the body. This suggests that it does not always stay in the gut or get removed easily.
In reviewing and analysing this study, the main lesson is that there is no simple or perfect replacement for sugar. Many people believe that switching to artificial or alternative sweeteners will protect them from weight gain, liver problems, and diabetes.
While these sweeteners may reduce the number of calories, they may still cause hidden harm inside the body. The study does not mean that everyone must immediately stop using all sugar substitutes. Instead, it encourages people to be more careful and more aware of what they are putting into their bodies.
The strongest message from the researchers is that balance is key. Natural, whole foods in reasonable amounts are still the safest choice.
Highly processed food, whether it contains real sugar or sugar substitutes, can create unexpected problems in the body over time. This new research reminds us that when it comes to sweeteners, there may truly be no “free lunch.”
If you care about liver health, please read studies about a diet that can treat fatty liver disease and obesity, and coffee drinkers may halve their risk of liver cancer.
For more information about liver health, please see recent studies that anti-inflammatory diet could help prevent fatty liver disease, and results showing vitamin D could help prevent non-alcoholic fatty liver disease.
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