In a similar way, it can be inferred that uncooked soy sauce used as a seasoning results in foods with a high NH3-N content. It appears that patients with high blood NH3-N levels in liver cirrhosis should eat foods with a low NH3-N content. Consequently, since non-heat-treated soy sauces contain a great deal of NH3-N, such patients should refrain from comsuming unprocessed soy sauce with their meals. We believe that education based on the above finding will have a significant therapeutic effect in preventing hepatic encephalopathy in association with hyperammonemia in patients with decompensated liver cirrhosis. The NH3-N content of a variety of foods was measured using the method described by Fujii and Okuda. A slightly high NH3-N content was detected in meat, chicken, and various canned foods. Extremely high concentrations of NH3-N were found in all soy sauces except the processed Dashiwari variety. Low NH3-N concentrations were found in fresh miso and milk. Since Dashiwari soy sauce was the only one with a low NH3-N content, it was concluded that NH3-N content decreased to 1/3 to 1/5 when foods were heated.