Consuming high amounts of eicosapentaenoic acid (EPA) and vitamin E in the diet may reduce the risk of developing hayfever, according to a new study in Allergy (2003;58:1277–84). These findings suggest that making relatively minor changes in the diet can significantly improve one’s allergies.
Hayfever or seasonal allergic rhinitis is caused by stimulation of the immune system (specifically IgE) in response to exposure to an inhaled allergen, such as pollen or mold . Studies suggest hayfever may affect as many as 41% of adults in Europe and up to 45% of adults in the United States. Genetic factors, environmental factors, housing conditions and lifestyle habits have all been identified as underlying causes. Conventional treatment includes antihistamines, such as fexofenadine (Allegra®), loratadine (Claritin®) and cetirizine (Zyrtec®) and steroidal nasal sprays, such as beclomethasone (Beconase®), triamcinolone (Nasacort®) and budesonide (Rhinocort®). Decongestants are often used as well. Incorporating foods high in EPA and vitamin E may reduce the need to use these medications.
In the new study, dietary intake questionnaires were completed by 334 adults with adult-onset hayfever and 1,336 adults who did not have hayfever. The amount of fatty acids and antioxidants in their diet was calculated, based on the responses given. Dietary intake of each nutrient was calculated by quartiles, with the first quartile having the lowest consumption and the fourth quartile having the highest intake amount of a specific nutrient. Dietary questionnaires were completed initially and again after approximately two years.
Those with the highest dietary intake of oleic acid and beta-carotene had an increased risk of developing hayfever, compared with participants with the lowest dietary intake of these nutrients. Oleic acid is found in animal products, such as red meat, as well as olive oil and other seed oils.[I couldn’t find a table that broke the content of oleic acid down, but it appears that animal products may have as much or more oleic acid than olive oil. Oleic acid is the most ubiquitous of all FA’s. People who have olive tree pollen allergy tend not to tolerate olive oil, because there is a lipid transfer protein that is passed into the oil. Its reasonable to consider that these oils do make peoples hayfever worse. Is there any data to suggest olive oil helps with hayfever?] Conversely, adults who consumed large amounts of EPA and vitamin E were at a reduced risk of getting hayfever, although these findings were mainly observed in women and ex-smokers. This suggests that benefits in treating hayfever with vitamin E and EPA may be limited to these two groups. An increased ratio of omega-3 to omega-6 fatty acids tended to decrease hayfever risk, but these results did not reach statistical significance.
Dietary habits in Western cultures may contribute the increased prevalence of hayfever observed over the last decade. In a typical western diet, consumption of omega-6 fatty acids from meat and dairy products is significantly higher than omega-3 fatty acids that are found mostly in fish, nuts and seeds. Studies suggest that eating more omega-6 fatty acids can lead to worsening of allergy symptoms, while omega-3 fatty acids may have a protective effect. Including more foods that are high in omega-3 fatty acids and vitamin E may help reduce the severity of hayfever symptoms. Foods rich in vitamin E include nuts and seeds, whole grains, dark, leafy vegetables and egg yolks. While the current study suggests this benefit may be limited to women and ex-smokers, these nutrients have other health benefits as well and may be worth trying before starting prescription or over-the-counter medications.