Gastric acid secretion levels are an important determinant of the manifestation of acid-related upper GI diseases such as gastroesophageal reflux disease. We recently reported that gastric acid secretion levels did not change from the 1990s to 2010s in H. pylori-negative asymptomatic Japanese outpatients with a mean age of 63 years old. However, because young people have a quite different lifestyle, including dietary pattern, from elderly people in Japan, it is worth investigating any chronologic changes in gastric acid secretion in younger generations. The aim of this analysis is to investigate the potential changes in gastric acid secretion from 1995 to 2014 in young Japanese healthy volunteers. Eighty-eight young Japanese healthy volunteers under the age of 40 with a mean age of 26 were extracted from a database accumulated from 1995 to 2014 for the present analysis. Their gastrin-stimulated gastric acid level was determined with the endoscopic gastrin test. In 76 H. pylori-negative subjects, gastric acid secretion levels showed a significant positive correlation with the calendar year when the test was performed (r = 0.27, p < 0.01). A similar trend was observed in 12 H. pylori-positive subjects. A chronological 5-year time period showed a significant positive association with gastric acid secretion in univariate and multivariate analyses (p < 0.01 and p = 0.01, respectively). Gastric acid secretion levels have been increasing in young Japanese healthy volunteers during the last 20 years. We need to monitor future trends in the prevalence of acid-related diseases such as gastro-esophageal reflux disease in Japan.
In modern society, fierce competition and socioeconomic interaction stress the quality of life, causing a negative influence on a person’s mental health. Laughter is a positive sensation, and seems to be a useful and healthy way to overcome stress. Laughter therapy is a kind of cognitive-behavioral therapies that could make physical, psychological, and social relationships healthy, ultimately improving the quality of life. Laughter therapy, as a non-pharmacological, alternative treatment, has a positive effect on the mental health and the immune system. In addition, laughter therapy does not require specialized preparations, such as suitable facilities and equipment, and it is easily accessible and acceptable. For these reasons, the medical community has taken notice and attempted to include laughter therapy to more traditional therapies. Decreasing stress-making hormones found in the blood, laughter can mitigate the effects of stress. Laughter decreases serum levels of cortisol, epinephrine, growth hormone, and 3,4-dihydrophenylacetic acid (a major dopamine catabolite), indicating a reversal of the stress response. Depression is a disease, where neurotransmitters in the brain, such as norepinephrine, dopamine, and serotonin, are reduced, and there is something wrong in the mood control circuit of the brain. Laughter can alter dopamine and serotonin activity. Furthermore, endorphins secreted by laughter can help when people are uncomfortable or in a depressed mood. Laughter therapy is a noninvasive and non-pharmacological alternative treatment for stress and depression, representative cases that have a negative influence on mental health. In conclusion, laughter therapy is effective and scientifically supported as a single or adjuvant therapy.