intolérances

Intolerances are conditions in which the body has difficulty processing certain substances, leading to adverse symptoms after exposure. They are distinct from immune-mediated reactions such as food allergies and from diseases driven by autoimmune or inflammatory processes. Intolerances are often dose-dependent and may involve enzymatic deficiencies, impaired absorption, or metabolic sensitivities rather than a true allergy.

Common forms include dietary intolerances, especially lactose intolerance caused by lactase enzyme deficiency, and fructose intolerance from malabsorption. Other examples include histamine intolerance, arising from reduced activity of the enzyme diamine oxidase, and various sensitivities to sugar alcohols like sorbitol. Some individuals report gluten-related intolerances that are not due to celiac disease, often referred to as non-celiac gluten sensitivity; this area is still studied and debated. In addition, some people experience intolerance to certain additives or preservatives, such as sulfites.

Diagnosis typically combines clinical history with elimination and reintroduction of suspected triggers. Supportive tests can include hydrogen breath tests for lactose or fructose malabsorption and, in some cases, genetic tests for lactase persistence. Management centers on avoiding or limiting identified triggers while ensuring adequate nutrition. Enzyme supplements (for example, lactase) or alternative products can help some individuals. Diet planning may be important to maintain essential nutrients when avoiding certain foods.

Intolerances can affect quality of life and daily functioning, particularly if triggers are common in the diet or environment. They are usually not life-threatening, but persistent symptoms warrant medical evaluation to exclude other conditions and to develop an appropriate management plan.