Allergy and bananas

The usual complaint of individuals affected by rhinoconjunctivitis and/or bronchial asthma occurs during the time when the fruits, often referred to as seeds, are released from bananas.

Population studies, hospital admission and/or health expenditure costs, have shown that in the last forty years, allergic diseases, especially bronchial asthma and allergic rhinoconjunctivitis, have experienced a clear increase in their prevalence.

Forty years is too short a period of time for any type of genetic change to have been responsible for such an increase. On the contrary, all current evidence points to the environmental changes that occurred in the preceding four decades as being responsible, at least in large part, for not only the increase in prevalence but also the greater difficulty in treating them. These changes, both environmental and those related to asthma and allergic rhinitis, have occurred mainly in developed countries, which is why they are often referred to as "changes due to Westernization of lifestyle" (1).

Until a few years ago, it was common for allergic patients to have contact with the outside restricted, in order to prevent exposure to supposed environmental aggressors such as wind, dew, climate change, humidity, and some allergens such as fungi and pollens.

Unfortunately, currently, this little contact with the outside world is a social habit and not a medical indication. Thus, in industrialized countries, the majority of individuals spend a large part of their lives in closed, poorly ventilated spaces, with high relative humidity, the presence of carpets, curtains, cloth dolls, household pets and plants, where the air can contain pollutants in concentrations higher than those found outside.

Consequently, the quality of the air in these closed spaces is currently considered as important or more important than the quality of the air outside for health in general and for allergic respiratory diseases in particular (2,3,4).

The quality of the external environment has also been drastically altered in recent decades by the indiscriminate deforestation of large jungle areas, an increase in the number of vehicles with the direct increase in emissions derived from oil, the greenhouse effect due to the burning of grasslands, and the indiscriminate use of insecticides. , pesticides, aerosols and the lack of pollution control measures in large industries, among other causes.

If we consider the allergens that most frequently sensitize the atopic population, a study of children in Buenos Aires (5) found that out of 584 patients with obstructive bronchial symptoms from 1 to 18 years of age, 60% presented associated rhinitis. of the cases and atopic dermatitis in 12,5%, 66% were allergic to at least one inhalant allergen, the most frequent sensitizers being: Dermatophagoides (56%), Alternaria (18%), Cockroaches (16%), epithelia from dog and cat (13%), grass pollens (12%) and banana (8%).

In Rosario, a city with climatic characteristics similar to Buenos Aires and with a significant population of trees of the Platanus hispanica species, the findings were similar (6). The prevalence of sensitization in 203 patients with asthma and/or rhinitis aged between 10 and 60 years was 90,6% for 6 species of house dust mites; 55,7% for 33 pollen species; 40,4% for 5 species of fungi; and 18,7% for two types of epithelia.

If we consider the difference between sensitization to purely indoor allergens such as house dust mites (184/203) compared to pollens (113/203), extra-home allergens par excellence, the difference is highly significant (p<0,001). . When particularly considering the sensitivity to Platanus hispanica (32/203) in relation to that of Dermatophagoides pteronyssinus (160/203), a mite of the pyroglyphidae family of greatest global significance, the difference is more evident (p<0,0001).

In the city of Buenos Aires, the analysis of the monthly pollen content in the atmosphere during a complete annual period allowed 77 varieties to be identified. The highest pollen concentrations are reached at the end of winter and during spring, with an annual peak in October, the majority of which comes from the pollination of cultivated trees and shrubs (cypresses, ashes, plane trees, maples, eucalyptus, mulberry trees, palm trees, reeds, privets and various grasses). A second annual peak of lesser importance is recorded in March due to the main contribution of casuarinas, compositas and chenopodiaceae. (7,8).

The pollination duration of Platanus hispanica is very short, ranging between 20 and 40 days (9), so if respiratory symptoms are due to this pollen, it can be effectively prevented with medication during that season.

The usual complaint of individuals affected by rhinoconjunctivitis and/or bronchial asthma occurs during the time when the fruits, often referred to as seeds, are shed from this tree.

These fruits are surrounded by tiny, fine spikes that, when carried by the wind, impact the already irritated mucosa of these patients, triggering respiratory symptoms. Non-allergic individuals may also manifest symptoms, especially conjunctival and/or nasal irritation, due to this cause.
If we take into account that trees represent the "lungs of the planet" and that they are one of the most important elements that oppose the changes that the environment is experiencing due to the factors detailed above and that the adverse effects caused by Platanus hispanica, although annoying, are transitory and the most important ones can be adequately prevented, we believe that it does not justify the elimination of these trees.


1. Platts-Mills TAE, Wheatley LM, Aalberse RC. Indoor versus outdoor allergens in allergic respiratory disease. Curr Op Immunol 1998;10(6):634-639
2. Platts-Mills TAE, Wheatley LM, Aalberse RC. Indoor versus outdoor allergens in allergic respiratory disease. Curr Opin Immunol 1998,10:634-39
3. Platts-Mills TA, Woodfolk JA, Chapman MD, Heymann PW. Changing concepts of allergic disease: the attempt to keep up with real changes in lifestyles. J Allergy Clin Immunol 1996;98(6 Pt 3):S297-S306
4. Wickman M, Bylin G, Lindfors A, Strand V. Allergen exposure and pollutants of the indoor and outdoor environment - interaction in allergic disease. Progress in Allergy and Clinical Immunology Vol 4, 150-152. Oehling AK & Huerta López JG editors, Cancún, 1997
5. Martel J, Benhabib O, Grillo M, Testa M, Axenfeld J, Poiron J, Kohan M. XIX Annual Conference on Progress in Allergy, Asthma and Immunology, 1995
6. Ardusso L. Aeropalynology of the city of Rosario and its relationship with allergic sensitization. Preview. Postgraduate Course in Allergy and Immunology. Rosario, October 1999.
7. Romero EJ, Majas FD, Noetinger M. Aerial pollen in the city of Buenos Aires. Arch Arg Allerg Immunol Clin 1992;23:142-62
8. Noetinger M. Three years of monitoring pollen rain in the City of Buenos Aires. Arch Arg Allerg Immunol Clin 1993;24:65-75
9. Ballestero LH; Monticelli JV. Pollinosis. Hachette SA Bookstore Page 120


Study carried out by the Argentine Association of Allergy and Immunology on bananas. This information was requested by the Legislature in 2000 and was presented to the Dip. Clori Yelicic, President of the Health Commission of the Legislature of the City of Buenos Aires - Ref. Note Nº339/C/SALUD - Request for reports about: Effects caused by the planting of banana trees (Platanus hispanica) on the health of the allergic population, but IT WAS NEVER SPREADED!

* By Dr. Ledit. R. Ardusso. Coordinator of the Allergens, Diagnostic Tests and Immunotherapy Committee. Argentine Association of Allergy and Clinical Immunology