High on Health: The Link Between Diet Sodas and Liver Disease

If you think drinking alcohol is the only way to damage your liver, think again. A new study is shaking up conventional ideas about soda and liver health, suggesting that even diet soda may carry serious risks. At the 2025 United European Gastroenterology Week in Berlin, researchers unveiled results linking both sugary and artificially sweetened drinks to a higher risk of Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) – previously and probably more commonly known as Non-Alcoholic Fatty Liver Disease (NAFLD). What’s more, diet versions may be associated with a higher risk in some respects than their sugary counterparts.

Sugary and Diet Drinks and Their Link to Liver Disease

Call it MASLD, NAFLD, or even just simply liver disease – whatever the name, it means a buildup of excess fat in the liver. This can lead to inflammation, fibrosis (scarring), and eventually permanent liver damage. It is becoming more common and carries serious long-term consequences.

“Our study shows that LNSSBs [low- or non-sugar-sweetened beverages] were actually linked to a higher risk of MASLD, even at modest intake levels such as a single can per day,” said lead study author Lihe Liu, a gastroenterology grad student at the First Affiliated Hospital of Soochow University in China. “These findings challenge the common perception that these drinks are harmless and highlight the need to reconsider their role in diet and liver health, especially as MASLD emerges as a global health concern.”

The research tracked nearly 124,000 participants with no known liver disease over roughly a ten-year period. Consumption of more than one standard can daily of either sugar-sweetened or low/non–sugar-sweetened beverages was associated with elevated liver risk. The sugar-sweetened drinks were linked with a roughly 50% increased risk of MASLD, while the low/non-sugar versions were tied to a 60% higher risk.

Even more concerning, the analysis revealed that only the diet drinks were significantly associated with liver-related mortality. In other words, among those who developed liver disease, only consumers of artificially sweetened beverages appeared to have higher odds of death from liver causes.

Liu suggested the results from the study may change the way we need to think about our drinks. “These findings challenge the common perception that these drinks are harmless and highlight the need to reconsider their role in diet and liver health.”

Regular sodas harm the liver by causing sugar and insulin spikes, but diet sodas may affect the body differently. Artificial sweeteners can upset gut bacteria, change appetite signals, and confuse how the body handles energy.

“Many people have the misconception that diet drinks are healthier for you than regular drinks, but this study demonstrates how both are positively associated with MASLD,” registered dietitian nutritionist Karen Z. Berg, MS, RD, CSO, CDN, who was not involved in this research, told Medical News Today. She continued:

“I highly encourage all patients to stick with water, or carbonated water, for the best health outcomes. Just because something says ‘zero calories’ or ‘less sugar’ [it] does not automatically equate with [being] healthier. There are a lot of chemicals that go into those beverages to give them the flavors people crave. Plain water, fruit infused water (homemade), unsweetened homemade iced tea, or seltzer [are] the way to go.”

Experts warn that the study has limits. It hasn’t been reviewed by other scientists yet, and the data is based on what people said they drank, which can be unreliable. The research also didn’t look at which specific sweeteners were used.

A positive takeaway from the study is that swapping just one daily soda — regular or diet — for water can lower your risk of liver disease. The drop in risk was about 13% for sugary soda and 15% for diet soda.