Single daily sugary or diet drink linked to 50-60% higher liver disease risk

A decade-long study of more than 123,000 British adults has upended a common assumption about diet drinks: that they are a safer choice than their sugary counterparts. The research, presented at the United European Gastroenterology Week in Berlin, found that consuming just one can of an artificially sweetened beverage per day raised the risk of developing metabolic dysfunction-associated steatotic liver disease (MASLD) by 60 percent. Sugar-sweetened drinks carried a similar burden, increasing risk by 50 percent.

The study tracked 123,788 UK participants over ten years, all of whom had no liver disease when the research began. Researchers documented their drink consumption through repeated 24-hour dietary questionnaires, a method designed to capture actual intake patterns rather than relying on memory or estimation. During the decade, 1,178 participants developed MASLD, and 108 died from liver-related causes. These numbers ground an otherwise abstract health warning in concrete human consequence.

MASDL, formerly called non-alcoholic fatty liver disease, occurs when fat accumulates in the liver tissue, potentially triggering inflammation, pain, fatigue, and loss of appetite. The condition has become a significant public health concern. A 2025 analysis of 92 studies estimated that 38 percent of the world's population now has MASLD—a 50 percent increase over the past two decades. The disease is increasingly recognized as a contributor to cardiovascular disease, type 2 diabetes, and kidney problems, meaning its effects ripple far beyond the liver itself.

Lihe Liu, the study's lead author, emphasized that the findings challenge a widespread belief. "SSBs have long been under scrutiny, while their 'diet' alternatives are often seen as the healthier choice," he said. "Both, however, are widely consumed and their effects on liver health have not been well understood." The research suggests that diet drinks may pose an equal or greater threat than their sugary equivalents, even at modest consumption levels.

The biological mechanisms differ between the two drink types. Sugar-sweetened beverages cause rapid spikes in blood glucose and insulin, promote weight gain, and increase uric acid levels—all pathways that lead to fat accumulation in the liver. Artificially sweetened drinks operate through a different route: they alter the gut microbiome, disrupt the body's sense of fullness, intensify cravings for sweet foods, and may trigger insulin secretion despite containing no sugar themselves. Both roads lead to the same destination.

The research team pointed toward practical interventions. Water emerged as the clear winner, removing what Liu called "the metabolic burden" while providing hydration without triggering the biological cascades that lead to liver fat accumulation. Beyond beverage choice, the researchers recommended maintaining a healthy weight, exercising regularly, and eating a balanced diet as strategies to significantly reduce liver disease risk.

The findings arrive at a moment when MASLD is emerging as a global health crisis, affecting more than a third of the world's population. The study suggests that one of the simplest interventions—replacing both sugary and diet drinks with water—could meaningfully alter that trajectory. Whether consumers and public health systems will act on that knowledge remains an open question.