After being ingested into the human body, the final metabolite is alkaline, and the body fluids of healthy people are weakly alkaline (pH value is 7.3-7.4). However, due to the decomposition of food in the body, pyrogluconic acid, lactic acid, and fatty acids are produced. In addition, due to work fatigue, overeating, excessive drinking, etc., residual substances in the body are not removed and harmful residues are produced, thus causing human fatigue. At this time, human body fluids are weakly acidic (pH value is 6.8-7). Japanese scholar Nagata Masamatsu has been committed to research on the medical functions of vinegar since 1971. He believes that among all drugs and foods, vinegar is the only food that can directly make human body fluids appear normal and weakly alkaline.