Associations of Food Intolerance with Irritable Bowel Syndrome, Psychological Symptoms, and Quality of Life

Abstract

Background & aims: The impact of different types of food intolerance on gastrointestinal symptoms and quality of life (QOL) is poorly understood. We aimed to investigate associations of food intolerance and type of intolerance with irritable bowel syndrome (IBS), health-related QOL, and psychological symptoms. Methods: We conducted an observational study of United States-based adults through an online survey. Demographics, culprit foods, symptoms, medical evaluation, Rome IV criteria for IBS, health-related QOL (Short-Form Health Survey 12), and anxiety and depression scores (Hospital Anxiety and Depression Scale) were collected in participants with self-reported food intolerance (lactose, non-lactose food, lactose plus food intolerance), and controls with no intolerance. Univariable associations of group with study endpoints were analyzed with the Kruskal-Wallis and Pearson χ2 or Fisher exact test. Multivariable comparisons were analyzed by logistic and linear regression. Results: A total of 197 patients with (59 lactose, 61 non-lactose food, 77 lactose plus food intolerance) and 273 patients without intolerance participated. Lactose, wheat, and eggs were the most common food triggers. Gas (54.2%), abdominal pain (40.2%), and diarrhea (37.3%) were frequently reported symptoms of food intolerance. Reactions caused 57.8% to eliminate the food. Rates of IBS, abnormal anxiety scores, and abnormal depression scores were highest in lactose plus food intolerance; Short-Form Health Survey 12 scores were lowest in lactose plus food intolerance. Multivariable analyses revealed all intolerance subgroups were more likely to have IBS than controls. Conclusions: Food intolerance is associated with IBS, anxiety, depression, and decreased health-related QOL and frequently leads to food elimination. Adults with lactose and lactose plus food intolerance have higher rates of IBS, increased psychological symptoms, and poorer QOL.