A new analysis presented at UEG Week 2025 in Berlin links both sugar-sweetened sodas and “sugar-free” sodas to a clearly higher risk of MASLD (metabolic dysfunction–associated steatotic liver disease). For people who drank more than 250 g per day (about one can), the risk of MASLD was 50% higher for sugar-sweetened drinks and 60% higher for low/zero versions. The results come from a prospective analysis of 123,788 UK Biobank participants followed for a median of 10.3 years.
“Light” Doesn’t Mean Neutral
The authors note that sugar-sweetened sodas have long been criticized, while diet versions were often seen as “safer.” The new data challenges this: diet sodas were also linked to higher deaths from liver causes, which was not seen for sugary sodas in a statistically significant way. Possible mechanisms include effects on the gut microbiome, fullness, and cravings for sweet foods.
Water as a Replacement
Replacing a daily serving of soda with water was linked to lower MASLD risk: about −12.8% for sugary sodas and −15.2% for low/zero sodas. Switching from one type of soda to the other did not bring benefits. Several outlets summarizing the UEG presentation report the same conclusion.
What Is MASLD?
MASLD (formerly NAFLD) is long-term fat build-up in the liver not caused by alcohol. It can lead to inflammation, fibrosis (scarring), and liver cancer. Expert reviews say it is now the most common chronic liver disease worldwide.
Important Limitations
This is an observational study (a conference abstract), so it does not prove cause and effect. Diet data are self-reported, and the full paper has not yet been peer-reviewed. Even so, the large sample, long follow-up, and consistent findings (MASLD, liver fat, liver-related mortality) make this a meaningful public-health signal.
