Think Fiber Is Always Healthy? Think Again

Fiber might not be as essential as you've been led to believe. Now, before you throw your kale smoothie at the screen in frustration, let's break down the science together, because the truth about fiber is way more complex and interesting than simply good or bad. Some people argue that fiber-rich foods are anti-inflammatory, but that's not entirely true. For example, a landmark randomized controlled trial published in the journal Cell found that some people were inflammatory responders to dietary fiber, meaning when they ate fiber they had more inflammation. Reading straight from the paper: Taken together, these data suggest divergent immune system responses to the high-fiber intervention, with high-inflammation participants exhibiting broad increases in steady-state immune activation. Which means inflammation. To be clear, this was not the majority of participants. And it's also worth noting that those with lower microbiome diversity tended to be the inflammatory responders to fiber. Another interesting discovery and point on this paper is that fermented foods were far more universally anti-inflammatory. So, as a practical tip, if your goal is to reduce inflammation and eat an anti-inflammatory diet, I'd capitalize on kimchi over broccoli.