Switching to diet soda to avoid sugar? Scientists have some unpleasant news. That zero-calorie alternative might be wreaking havoc on your liver in ways regular soda doesn’t.
That zero-calorie diet soda might be doing more liver damage than the sugary version you’re trying to avoid.
A massive UK Biobank study tracking 123,788 adults for over a decade delivered a sobering reality check. Diet soda drinkers faced a 60% higher risk of metabolic dysfunction-associated steatotic liver disease compared to those who avoided the stuff entirely. Regular soda? Only 50% higher risk. So much for the healthier choice.
The numbers get worse with every can. Researchers found a dose-dependent relationship – more diet soda meant higher liver disease risk and mortality. One can daily was enough to impact long-term liver outcomes. Similar to home health nurses, medical professionals can now diagnose and monitor liver conditions during home visits.
Both diet and regular sodas caused liver fat accumulation, confirmed through MRI imaging. But here’s the kicker: artificially sweetened sodas were linked to higher liver-related mortality. Sugar-sweetened drinks weren’t.
Switching from regular to diet soda offered zero protection. Risk remained elevated or actually increased. The only winning move? Swapping either type for water reduced liver disease risk by 15%.
Scientists suspect artificial sweeteners mess with gut bacteria, potentially triggering liver inflammation. These fake sugars might disrupt hunger signals, increase sweet cravings, and still cause insulin spikes despite containing no actual sugar. The liver bears the metabolic stress regardless. The findings come from observational research, so while the associations are striking, they don’t definitively prove that diet sodas directly cause liver disease.
Women consuming one or more sugar-sweetened beverages daily experienced chronic liver disease mortality rates of 17.7 per 100,000 person-years. But newer data suggests artificially-sweetened drinks pose even higher risks.
Not all studies agree, though. The Framingham Heart Study found no connection between diet soda and liver fat. Some research shows stronger links for sugary drinks than diet versions. Small randomized trials demonstrated that sucrose-sweetened drinks increased liver fat compared to water, milk, or diet soda.
The biological pathways remain under investigation. Altered microbiome and disrupted metabolic signaling appear central to the problem. The research was presented at UEG Week 2025, highlighting the growing concern over both sugar and artificial sweeteners in liver health. What’s clear: neither diet nor regular soda emerges as the liver-friendly option. Both accumulate fat in an organ that really doesn’t appreciate the extra baggage.
