We all know the great feeling of relaxing with a cold soda, whether it’s during a movie, after a long day of work, or while soaking up the sun at the beach in the summertime. For decades, sodas have been a go-to beverage for many, offering both refreshment and a quick burst of sweetness. In recent years, however, more people have turned to diet versions of these drinks, believing they are the healthier choice because they contain little or no sugar. While diet sodas are often marketed as a guilt-free indulgence, recent research has raised serious concerns about their potential effects on long-term health. Experts now warn that even small amounts of diet soda, and not just regular sugary drinks, can have a negative impact on the liver, potentially leading to significant health problems. This caution is especially striking because many people assume that limiting themselves to a single can a day or occasionally enjoying a sweetened beverage is harmless.

A study presented on October 6 at the 2025 United European Gastroenterology Week conference in Berlin provides clear evidence that even moderate consumption of artificially sweetened or sugary beverages may pose health risks. According to the study, drinking diet soda or sugar-sweetened drinks in moderation is associated with an increased risk of developing liver disease, even at levels previously considered safe. The researchers emphasize that this is not only an issue for heavy soda drinkers but also for those who consume these beverages in smaller quantities. These findings challenge long-standing assumptions about diet sodas being a safe alternative, showing that artificial sweeteners may carry risks of their own. The revelation has raised concerns among health professionals and consumers alike, prompting calls for increased awareness about the potential dangers of both diet and regular sodas.

One of the most concerning findings of the study is the relationship between soda consumption and Metabolically Dysregulated Steatotic Liver Disease (MASLD), a condition formerly known as non-alcoholic fatty liver disease. The research indicates that consuming as little as nine ounces of a sugary drink per day can increase the risk of MASLD by approximately 50%. Surprisingly, the same daily intake of a single diet soda may increase the risk even further, by about 60%. MASLD occurs when fat builds up in the liver, and it is now recognized as the most common form of liver disease worldwide. Over time, MASLD can lead to severe liver scarring, cirrhosis, or even liver failure, mirroring the damaging effects typically associated with chronic alcohol abuse. The condition often progresses silently, showing few symptoms until serious damage has occurred, which makes early prevention and awareness particularly crucial.

Lihe Liu, a graduate student in the Department of Gastroenterology at the First Affiliated Hospital of Soochow University in Suzhou, China, and the lead author of the study, explained the findings in detail. Liu stated, “Our study shows that 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.” The mechanisms behind these effects differ depending on the type of beverage. Sugary drinks, or sugar-sweetened beverages (SSBs), can lead to rapid spikes in blood glucose and insulin, which promote weight gain, elevate uric acid levels, and contribute to fat accumulation in the liver. On the other hand, low- or non-sugar-sweetened beverages (LNSSBs), such as diet sodas, may negatively affect liver health through other mechanisms. These can include altering the gut microbiome, disrupting the sense of fullness after eating, increasing sweet cravings, and even stimulating insulin secretion. Such findings highlight that even products designed to be “healthy” substitutes may carry hidden risks.

The potential harms of soda consumption are not entirely new revelations. Researchers have long warned about the dangers of added sugars, such as cane sugar and high-fructose corn syrup, which can harm multiple aspects of health. Carbonation in sodas can also affect the stomach, sometimes causing bloating or digestive discomfort. Dr. Wesley McWhorter, spokesperson for the Academy of Nutrition and Dietetics, explained to USA Today that while the body processes glucose and fructose differently, fructose is primarily metabolized in the liver. When consumed in excess from concentrated sources like sugary drinks, fructose can lead to fat buildup in the liver, which is a key contributor to non-alcoholic fatty liver disease. This further emphasizes that both sugary and diet sodas may have unintended consequences on liver health, making moderation and informed choices essential.

The study also highlights the misconception that diet sodas are a safer alternative to sugar-sweetened beverages. While sugar-laden drinks have been widely criticized for decades, their diet counterparts are often assumed to be harmless. However, Liu notes that the effects of both types of beverages on liver health have not been fully understood until now. In addition, broader public health discussions are starting to address the impact of food ingredients beyond sugar, such as artificial dyes. In 2025, efforts were made to remove some artificial ingredients from popular beverages, and certain companies, like Coca-Cola, began using cane sugar in some US products. These developments, combined with emerging research, suggest that consumers need to be more aware of the potential health effects of all sodas. Whether choosing sugary or diet varieties, it is clear that frequent consumption carries risks, particularly for the liver, and moderation, along with a balanced diet, remains the safest approach to enjoying these beverages.