Arthritis linked to tryptophan in new study — here’s what to eat instead

It’s hard to be a fan of tryptophan these days.

The essential amino acid oft-blamed for inducing sleepiness after Thanksgiving dinner has given us another reason to say no thanks to meats, dairy, nuts, grains and legumes — and yes to Mediterranean diet staples.

University of Colorado researchers have found a link between arthritis and tryptophan, calling their findings the first to describe how the chemical breaks down in the body and causes inflammation.

Tryptophan is used by the body to build proteins, muscles, enzymes and neurotransmitters. What’s left, the study published in the Journal of Clinical Investigation revealed, may be broken down to produce an inflammatory chemical that facilitates the development of rheumatoid arthritis, an autoimmune disease affecting the joints.

Tests on lab mice showed that tryptophan is broken down into indole — a molecule closely associated with feces — which activates autoreactive inflammatory T-cells in their body.

When tryptophan hits our gut bacteria break it down into byproducts, but what they become depends on where they’re used. “If tryptophan hits our body’s cells, it tends to go get broken down into anti-inflammatory products versus when it hits the bacterial cells and goes more inflammatory,” explained Dr. Kristin Kuhn, associate professor and head of the CU Division of Rheumatology.

Some readers may also be inspired to swap their T-Day turkey for Greek-style branzino as study authors have claimed their results suggest that the Mediterranean diet, which emphasizes plant-based dishes and lean marine proteins, seems to avoid the immune-triggering effects of tryptophan.

The diet voted best in the world by doctors and diners alike “seems to push the microbiome into a healthier state, so that you are getting the anti-inflammatory properties of tryptophan, whereas the typical western diet seems to go more toward the inflammatory pathway,” the study co-author claimed.

Researchers hope to uncover other simple changes that could prevent arthritis from setting in.

“We have started to understand the at-risk stage, where we can actually identify people who are likely to progress to rheumatoid arthritis within the next few years based on blood markers,” said Kuhn, who’s pushed for more research to explore the best way to go about it. “We’re not quite sure yet what are the right ways to intervene.”