While most people can tolerate sulfites without any issues, some individuals may be sensitive or allergic to them. Sulfite sensitivity can manifest as symptoms ranging from mild to severe, including headaches, respiratory problems, hives, digestive issues, and in rare cases, life-threatening allergic reactions. Sulfites may cause the increased production of highly volatile compounds called free radicals, which could play a role in why people with asthma may have a higher sensitivity to sulfites. While more human research is needed, some sulfites have been shown to inhibit the growth of beneficial bacteria, thus indicating an effect on the microbiome. Sodium metabisulfite has been associated with negative health effects in rat studies, including affecting heart function, inducing apoptosis of gastric cells, and having a prooxidant effect in the liver and kidney. Due to many reported adverse reactions such as anaphylactic and asthmatic reactions with increased use of sulphites in the 1970’s and ‘80’s, the FDA banned the use of sulphites in fresh fruits and vegetables.