Recent research indicates that consuming a particular sweetener may elevate the likelihood of developing liver disease.

Experts have discovered that sorbitol, a sugar alcohol frequently used as a sugar alternative in various diet sodas, sugar-free gums, low-sugar candies, ice creams, desserts, and some low-calorie fruit beverages, could increase the chances of fatty liver disease.

This condition, affecting almost 100 million individuals in the United States, involves the accumulation of harmful fats in the liver, leading to inflammation, scarring, and potentially even liver failure.

At Washington University in St. Louis, scientists conducted experiments on zebrafish, revealing that sorbitol, chosen as a sugar substitute due to its lower caloric value, is naturally produced in the gut when glucose levels rise. Normally, healthy gut bacteria would eliminate it.

However, when these bacteria are absent—often a result of taking specific medications—the sorbitol instead travels to the liver, where it promotes fat accumulation. This occurs because sorbitol converts into fructose, which subsequently turns into fat.

The researchers concluded in their study: “These findings suggest that gut bacteria capable of degrading sorbitol play a protective role against the development of fatty liver disease.”

‘It suggests that excessive intake of dietary sorbitol may pose a risk for the development of [fatty liver disease].’

The tests were carried out in fish and will need to be repeated in humans to confirm the results, although the researchers said it was a clear warning about the risks posed by sorbitol.

It has been widely reported that President Trump frequently enjoys a diet soda, which sometimes contains sorbitol (file photo)

Sorbitol is a sugar alcohol found naturally in fruits like apples and peaches, but is also manufactured for use as a low-calorie sweetener.

Fatty liver disease can be caused by being overweight or obese, resistance to  insulin, being diabetic or having high levels of fat in the blood.

It does not always cause symptoms, and doctors say the majority of cases are undiagnosed. Some warning signs can include abdominal pain, a feeling of fullness, extreme exhaustion or weakness. 

Other symptoms include nausea, loss of appetite, unexplained weight loss, yellowish skin and whites of the eyes, swelling in the abdomen, legs, feet or hands.

Without treatment, the condition can progress to scarring of the liver, which can then cause liver failure, although it can take years to reach this state. 

To treat the condition, patients may be prescribed medications, told to lose weight or advised to avoid alcohol.

In severe cases, a liver transplant may be needed. 

In the study, published in Science Signaling, the researchers found that sorbitol could be made in the gut naturally by an enzyme that was activated whenever glucose, sugar levels, were too high.

Normally, they said, it was neutralized by Aeromonas bacteria, which is found in Zebrafish and in humans only when it is causing an infection – it is not part of the natural human microbiome, although the researchers said other bacteria could fulfil the same role.

It was not clear how much sorbitol someone might need to consume to raise their risk of fatty liver disease, or how much sorbitol can be safely neutralized by the microbiome. 

Sorbitol is a sugar alcohol used as a sugar substitute added to some diet sodas, sugar-free gums, low-sugar candy, ice cream and desserts, as well as some low-calorie fruit drinks

Dr Gary Patti, a metabolism researcher from Washington University in St Louis, who led the study, said: ‘[Sorbitol] can be produced in the body at significant levels. But, if you have the right bacteria, turns out, it doesn’t matter.

‘However, if you don’t have the right bacteria, that’s when it becomes problematic.  Because in those conditions, sorbitol doesn’t get degraded and, as a result, it is passed onto the liver.’

The researchers behind this study have also previously warned that fructose has negative health effects, including turbo-charging cancer cells.

Fructose — which is also added to thousands of foods and drinks — was found to speed up the growth of certain kinds of skin, breast and cervical tumors.

Their study, published in December last year, showed this type of sugar gets converted by the liver into components that tumors need to build new cells and grow.

The more quickly a tumor grows, the more aggressive the cancer may become, able to take over a person’s body before it can fight back.

Fructose is a sugar that is extracted from sources like corn and added to processed foods, most commonly in the form of high fructose corn syrup.

Some early studies have suggested that eating more of these processed sugars might not just accelerate cancer growth, but could also be a cause of some kinds of cancer.

Added fructose is different from fruit fructose, a natural sugar found in fruits that is typically accompanied by fiber and other nutrients that slow down its absorption into the blood.

In the US, manufacturers are generally allowed to add fructose to foods without limitation, which means it’s found in high amounts in many different processed foods.