Hay fever is often caused due to exposure to an allergen. About 10 to 40 percent of the European population suffers from hay fever. Genetic factors as well as many environmental factors influence the generation of an allergic reaction to a particular allergen. The present study aimed at evaluating the role of consumption of different fatty acids and antioxidants in the genesis of hay fever. The results of the study showed that dietary factors could impact the risk of hay fever and the onset of symptoms.
The central mechanism in the generation of hay fever is the production of substances such as prostaglandins, which in turn enhance the production of a specific immunoglobulin, IgE. Prostaglandins are derived from arachidonic acid, a fatty acid present in animal foods. Oxidant injury also enhances allergic reaction. Many earlier researchers have shown that there is an association between consumption of certain foods and incidence of allergic disorders such as hay fever. But most of these studies did not calculate the amount of different nutrients that the subjects of the study consumed. Hence, this study was undertaken to measure the amounts of different fatty acids and antioxidants consumed and their association with hay fever was assessed.
* Participants of the present study were picked from a larger parent study “European Prospective Investigation into Cancer and Nutrition,” designed to determine the association of food with various chronic diseases, especially cancers.
* A total of 334 individuals suffering from hay fever and 1336 controls were recruited for the study.
* A “Food Frequency Questionnaire” was supplied to all the participants, to find out their average food consumption. The intake of various fatty acids and antioxidants such as vitamin E and beta carotene were measured using “National food tables BLS, version II.3”.
* Other details of patients such as their education, sports activity, and smoking history were also collected.
* Participants consuming higher amounts of oleic acid suffered more frequently from hay fever.
* It was found that an increased intake of eicosapantaenoic acid led to decrease in the risk of symptoms of hay fever. Other fatty acids had no significant role to play in the genesis of hay fever.
* Higher intake of ß carotene was increasingly linked with hay fever. But higher consumption of vitamin E protected against hay fever.
* Among women, increased consumption of linoleic acid, and in non-smokers, increased intake of oleic acid, were positively associated with the occurrence of hay fever.
All the cases of hay fever included in the study were diagnosed by physicians. No self-diagnosed cases were included, as it would have led to erroneous high numbers. But at the same time, many cases might have been missed. The dietary intake assessment of the present study is based on self reported data, which may be biased.
The present study has provided added proof that diet also plays a role in the development of allergic reactions. There are basically two types of polyunsatuared fatty acids- n-3 and n-6. Eicosapantaenoic acid belongs to the type n-3 and arachidonic acid belongs to the type n-6. The ratio of n-3 to n-6 influences prostaglandin production. The present study has shown that a high level of n-3 type i.e. high consumption of eicosapantaenoic acid reduces the risk of hay fever. Vitamin E also decreases the risk of hay fever, through its powerful antioxidant property. Whether change of food habits alters the occurrence of hay fever needs to be assessed in future studies.
For More Information:
The Influence of the Dietary Intake of Fatty Acids and Antioxidants on Hay Fever in Adults
Publication Journal: Allergy, 2003
By G Nagel; A Nieters; German Cancer Research Center, Heidelberg, Germany
*FYI Living Lab Reports Are Summaries of the Original Research.