Consumption of Certain Types of Mushrooms
My thanks go to the authors of the clear article on micro- and macrohematuria (1). Allow me one additional point preceding the diagnostic evaluation: if patients notice that their urine is red—and they think it contains blood—they will be very concerned and therefore seek medical advice.
If subsequently urinalysis for blood yields a negative result in the practice setting or outpatient setting, and if no erythrocytes are seen on the microscope’s field of vision, the doctor will consider myoglobinuria, porphyria, or, in particular, hemoglobinuria after excessive exercise (for example, “march” hemoglobinuria). What is also generally known is the fact that consumption of beetroot can stain urine red because beetroot contains betaine.
What is less well known, however, is the fact that
ingestion of certain types of fungi/mushrooms can stain urine red. The first to mention in this context is the
saffron milk cap mushroom (Lactarius deliciosus), which is very popular with mushroom pickers/foragers and which surfaces in late summer and autumn around pines.
The mushroom is in the family of Russulaceae. But all other types of mushrooms whose gills—when cut—release bright red-orange latex that eventually turns wine red and which are all edible (such as the Lactarius salmonicolor mushroom and the very common false saffron milk cap [Lactarius deterrimus] and others)—can cause red or brownish-red staining of the urine.
The reason for this is the azulene (sesquiterpene) content in the fruiting bodies of these mushrooms. During long years of working as an assistant and senior physician, I was able on several occasions to calm down worried patients by asking if they had eaten beetroot or Lactarious mushrooms on the previous day and spare them further diagnostic evaluation.
Prof. Dr. med Siegmar Berndt
Toxikologe der Deutschen Gesellschaft für Mykologie e. V., Paderborn
Conflict of interest statement
The author declares that no conflict of interest exists.
|1.||Bolenz C, Schröppel B, Eisenhardt A, Schmitz-Dräger BJ, Grimm MO: The investigation of hematuria. Dtsch Arztebl Int 2018; 115: 801–7 VOLLTEXT|