Gas-related symptoms are associated with poorer quality of life, and higher stress, anxiety and depression.
Other gas-related symptoms included stomach rumbling, which affected 60.5 percent of respondents, closely followed by belching (58 percent) and bad breath (48.1 percent). Trapped wind (47.2 percent), abdominal distension/swollen tummy (39.6 percent) and bloating/abdominal pressure (38.5 percent) also had a noticeable impact, while only 11.1 percent of respondents reported having no gas symptoms. On average survey participants had been affected by three different gas symptoms within the previous 24-hour period.
The findings from the study, which surveyed nearly 6,000 people across the United States, United Kingdom, and Mexico, were based on a representative sample of people aged 18 to 99 years asked to fill out validated Intestinal Gas Questionnaires (IGQs) via the internet, to measure the presence and severity of seven gas-related symptoms in the last 24 hours. Researchers also collected information on body mass index, exercise, emotional wellbeing, and quality of life in the past seven days.
The survey, conducted by scientists from the Rome Foundation Research Institute in the U.S. in collaboration with Danone Nutricia Research in France, revealed that higher IGQ scores correlated with lower mental health and quality of life scores on the PROMIS Global-10 questionnaire, higher stress, anxiety, and depression, and more non-gastrointestinal (GI) symptoms. However, IGC scores did not correlate with weight/BMI and only had a modest negative association with the amount of exercise taken.
Younger people aged 18 to 34 and 35 to 49 had the highest overall burden of gas-related symptoms, with IGQ total scores of 24 and 22.6 respectively, compared to 12.7 in people aged 50 to 64 and 8.6 in the over 65s. People in Mexico had higher scores for all seven gas symptoms in IGQ questionnaires, and a higher average IGQ total score, of 26 compared to 14.5 in the US and 13.7 in the UK.
Lead author, Professor Olafur Palsson from the University of North Carolina Department of Medicine, said: "I think the most remarkable and surprising finding in our study is that almost all adults in the general population experience some daily gas-related symptoms. This is important, given the data also clearly reveals that these symptoms affect people's general wellbeing. Having a high amount of these common intestinal symptoms is associated with higher levels of depression, anxiety and stress, as well as impaired general quality of life."
He added, "The reasons for the marked differences in the amount of gas-related symptoms between Mexico and the other countries we surveyed are unknown, and need to be investigated further. Cultural, linguistic, diet or public health factors might affect population levels of gas-related symptoms."
The survey methods used included the IGQ, the Patient Health Questionnaire non-GI physical symptoms (PHQ-12) and anxiety and depression (PHQ-4) scales, the PROMIS Global-10 QoL questionnaire and questions on exercises amount, height, weight, and life stress.