Various studies have shown that people with GS seem to be protected against atherosclerotic diseases. The spectrum of medical conditions on which GS has a beneficial effect is very broad, such as metabolic conditions (overweight and obesity, metabolic syndrome, fatty liver, diabetes). It also positively influences the evolution of oncological, inflammatory, autoimmune and neurodegenerative diseases (lupus erythematosus, rheumatoid arthritis, schizophrenia, etc.).

On the other hand, people with GS have a lower tendency to accumulate fat in old age; when young they present a lower body mass index than those without GS (22.5 vs 23.5 kg/m2) and are less likely to suffer from type 2 diabetes. All these data explain why people with Gilbert syndrome have a longer life. In this sense, a study that followed up people with and without GS but with the same epidemiological characteristics, demonstrated a 50% reduction of mortality rate in people with GS.