BackgroundThe increase in food intolerances poses a burgeoning problem in our society. Food intolerances not only lead to physical impairment of the individual patient but also result in a high socio-economic burden due to factors such as the treatment required as well as absenteeism. The present study aimed to explore whether lactose intolerant (LI) patients exhibit more frequent comorbidities than non-LI patients.MethodsThe study was conducted on a case-control basis and the results were determined using routine data analysis. Routine data from the IMS Disease Analyzer database were used for this purpose. A total of 6,758 data records were processed and analyzed.ResultsThere were significant correlations between LI and the incidence of osteoporosis, changes in mental status, and the presence of additional food intolerances. Comparing 3,379 LI vs. 3,379 non-LI patients, 34.5% vs. 17.7% (P<0.0001) suffered from abdominal pain; 30.6% vs. 17.2% (P<0.0001) from gastrointestinal infections; and 20.9% vs. 16.0% (P=0.0053) from depression. Adjusted odds ratios (OR) were the highest for fructose intolerance (n=229 LI vs. n=7 non-LI; OR 31.06; P<0.0001), irritable bowel syndrome (n=247 LI vs. n=44 non-LI; OR 5.23; P<0.0001), and bloating (n=351 LI vs. n=68 non-LI; OR 4.94; P<0.0001).ConclusionThe study confirms that LI should not be regarded as an isolated illness but considered a possible trigger for further diseases. Additional research is necessary to assert more precise statements.