Beta-hydroxybutyrate reduces symptoms of gout.
Gout is a painful, debilitating disease that affects more than 8 million people living in the United States. The condition arises when uric acid crystals form in and around the joints, causing inflammation, pain, and impaired mobility. Evidence from a 2017 study suggests that beta-hydroxybutyrate inhibits the activity of the NLRP3 inflammasome, reducing symptoms of gout.
Beta-hydroxybutyrate is a type of ketone body. It forms in the liver via the breakdown of fatty acids and can be used to produce energy in the mitochondria. Beta-hydroxybutyrate also acts as a signaling molecule that alters gene expression via a wide range of molecular pathways. Ketogenic diets induce beta-hydroxybutyrate production.
Inflammasomes are large, intracellular complexes that detect and respond to internal and external threats. Activation of inflammasomes has been implicated in a host of inflammatory disorders. The NLRP3 inflammasome, in particular, triggers the release of the proinflammatory proteins interleukin (IL)-1 beta and IL-18 and drives pyroptosis, a form of cell death that is triggered by proinflammatory signals and closely linked with inflammation.
The study involved rats that are prone to developing gout. The investigators fed one group of the rats a normal diet and fed another group a ketogenic diet. After one week, they measured ketones present in the animals' urine. They found that the ketogenic diet induced production of beta-hydroxybutyrate, which in turn protected the animals against uric acid-induced elevations in IL-1 beta. Examination of the animals' joints revealed that the rats that ate the ketogenic diet had less joint inflammation than those fed a normal diet.
Next, the investigators assessed the effects of beta-hydroxybutyrate on neutrophils, a type of immune cell, from both young and old humans. They found that the compound inhibited the NLRP3 inflammasome-induced IL-1 beta secretion in both young and old neutrophils, suggesting that the ketone plays a role in activating the inflammasome in neutrophils, regardless of age.
These findings suggest that beta-hydroxybutyrate inhibits the activity of the NLRP3 inflammasome, reducing the symptoms of gout. Researchers do not know if these results translate to humans, however. Learn more about the health effects of beta-hydroxybutyrate in our overview article.