A Stanford trial found high-dose inulin, a common fiber supplement, spiked liver injury markers so severely the study stopped early. Lower doses may help fatty liver disease, but the research suggests dosage and individual response matter more than the blanket advice that all fiber is universally good.
Can fiber damage your liver? Well, it can, but not this fiber, and wait because this isn't just clickbait. A landmark randomized controlled trial conducted at Stanford tested different types of fiber on individuals, and one common fiber type, inulin, at high doses spiked ALT, a marker of liver injury, in a subset of people. The effect was so big they actually stopped the study early in these participants out of concern for their safety. And they even cite preclinical data hinting that high-dose, long-term insulin intake might raise liver cancer risk, which is totally counterintuitive, right? Because we're told fiber is always good. But here's the nuance: dose matters, and different people respond differently. Lower doses of insulin might even help liver health, decrease fatty liver, improve insulin sensitivity, but the higher doses can harm the liver in a minority. So the point here isn't fiber is bad, it's context over dogma.
