Mycotoxins are secondary toxic metabolites produced by moulds that contaminate a variety of agricultural products before, during or after harvest. They are in fact naturally occurring toxins produced by certain species of moulds (fungi) and can be found in food (1) (2). Globalisation and food production, together with climate change, are linked to the presence of emerging contaminants in food products and the environment, which represent a threat to animal and human health (3).
Human exposure to these moulds can happen directly when eating infected food or indirectly from animals fed with contaminated feed, and in particular by drinking animal milk (1). Major mycotoxin-producing mould genera include:
Aspergillus (hay and compost). Most people inhale Aspergillus spores every day without getting sick. However, people with a weak immune system or lung diseases are at a greater risk for developing health issues due to Aspergillus, including allergic reactions, lung infections and infections in other organs (2). Foods where this mycotoxin may be found include grapes, cocoa seeds and ham (4).
Fusarium (soil and plants). Fusarium species are important plant pathogens causing various diseases such as crown rot (disease in trees and plants), head blight (disease in grains) and scab on cereal grains, which can occasionally cause infections in humans and animals, including superficial infections (keratitis and onychomycosis), allergic diseases (sinusitis) and mycotoxicosis in humans and animals following ingestion of food contaminated by Fusarium (5). Plants where this mycotoxin may be found include corn and tiger nut, but it can also be found in different varieties of fish (4).
Penicillium is one of the most common fungi found in a wide variety of habitats, from soil to vegetation, air, indoor environments and various food products (6). This fungus may be found in fruits and vegetables, such as onions, peppers, tomatoes and tomato-derived products (ketchup, juices, soups), berries, etc. (4).
Mycotoxins can cause a variety of adverse health effects on humans. In low concentrations, nausea, gastrointestinal disorders and vomiting have been reported, whereas high concentrations have been linked to the induction of cancers such as oesophageal cancer, and immune deficiency (1). In Spain, the highest concentrations of mycotoxins were associated with rural areas, lower social class, and beer, light sodas and fruit juice consumers (3). Food with higher concentrations of mycotoxins in Spain are refrigerated pizza dough, paprika, coffee, cocoa, wine, Iberian ham and liquorice (7).
The World Health Organization advise people to (1):
- Inspect whole grains, especially corn, sorghum, wheat and rice.
- Avoid damage to grains before and during drying, and in storage.
- Store food properly, kept free from insects, dry and not too warm.
- Not keep foods for extended periods before being used.
- Ensure a diverse diet to reduce mycotoxins exposure.
References
- Micotoxinas [Internet]. [cited 19 November 2023]. Available at: https://www.who.int/es/news-room/fact-sheets/detail/mycotoxins
- Aspergillosis | Types of Fungal Diseases | Fungal Diseases | CDC [Internet]. 2021 [cited 19 November 2023]. Available at: https://www.cdc.gov/fungal/diseases/aspergillosis/spanish/index.html
- Dasí-Navarro N, Lozano M, Llop S, Vioque J, Peiro J, Esplugues A, et al. Associated factors with mycotoxin exposure in Spanish population. Environ Res. 14 November 2023;117618.
- Illana C. Micotoxinas en España II. 22 October 2019;
- Nucci M, Anaissie E. Fusarium Infections in Immunocompromised Patients. Clin Microbiol Rev. October 2007;20(4):695-704.
- Visagie CM, Houbraken J, Frisvad JC, Hong SB, Klaassen CHW, Perrone G, et al. Identification and nomenclature of the genus Penicillium. Stud Mycol. June 2014;78:343-71.
- Aesan – Agencia Española de Seguridad Alimentaria y Nutrición [Internet]. [cited 19 November 2023]. Available at: https://www.aesan.gob.es/AECOSAN/web/seguridad_alimentaria/subdetalle/micotoxinas.htm
Mónica Miriam García Cuéllar
Master’s Degree in Public Health and Health Promotion
OSMAN Scientific Editor