Is fever a symptom of glycine deficiency?
A viral hypothesis suggests glycine deficiency may cause fever and poor sleep by impairing antioxidant production.
A provocative hypothesis from Benquo on LessWrong is challenging conventional views on sleep and fever by pointing to a common amino acid. The theory posits that glycine deficiency—common in modern diets—may be a root cause of increased sleep need and could even explain fever. The body synthesizes only about 3 grams of glycine per day, but total daily requirements are estimated between 10 to 60 grams, especially for those in poor health. This shortfall is critical because glycine is a key component of glutathione, the body's primary intracellular antioxidant.
During wakefulness, mitochondria generate reactive oxygen species (ROS) as a metabolic byproduct. Sleep is the period for clearing this oxidative damage via glutathione. If glycine is deficient, glutathione production bottlenecks, ROS clearance slows, and more sleep is needed for recovery. Furthermore, Benquo speculates that fever—a metabolically costly immune response—might be triggered when the body is too glycine-depleted to fight infection through more precise, glycine-enabled mechanisms. This connects two seemingly disparate biological phenomena to a single nutritional deficiency.
- Glycine is required for glutathione production, the body's main antioxidant for clearing oxidative stress accumulated during wakefulness.
- Modern diets provide far less than the estimated 10-60g daily glycine need, creating a widespread potential deficiency.
- The theory suggests fever may be a less efficient immune response activated when glycine levels are too low for optimal repair.
Why It Matters
This reframes chronic sleep issues and immune response as potentially addressable through targeted nutrition, not just pharmacology.