Influence of linolenic [omega 3] and linoleic [omega 6] poly unsaturated fatty acid containing oils on an experimentally induced model of atopy

ABSTRACT

Atopy or atopic syndrome is an allergic hypersensitivity reaction affecting nose, eyes, skin, and lungs. In the typical Western diet, 20-25-fold more omega-6 [linoleic acid] than omega-3 [linolenic] polyunsaturated fats are consumed. The Mediterranean-style diet high in alpha linolenic acid [ALA] has been shown to markedly reduce the recurrence rate after a first myocardial infarction. Epidemiologic studies have also shown that a higher intake of ALA protects against fatal ischemic heart disease and is associated with a reduced prevalence of coronary artery disease in both men and women. The aim of this work is to study the effect of short term daily oral feeding with diet containing linseed oil [omega-3, alpha linolenic acid] or sunflower [omega-6, linoleic acid] on the experimentally induced model of atopy in rats. 60 male Sprague Dawlley rats were divided into three equal groups. The first group is the control group where the animals were fed with normal diet, the second group was fed with diet containing 5% linseed oil for 28 days and the third group was fed with diet contains 5% sunflower oil for 28 days. Blood samples were taken at the day for the determination of the total number of oesinophils. While the animals were under the same condition of diet feeding, animals of each group were vaccinated by i.p. injection with 0.1 ml sterile saline solution containing 150 ng of Haemophilus influenza type b vaccine five times! week for another 28 days. Blood samples were withdrawn two times per week from each group of animals to follow up the changes in the eosinophils number. The results showed that linseed containing diet sharply decreased the peripheral number of circulating eosinophils, while sunflower containing diet significantly increased this number. Also the observed changes in the eosinophils number, due to repeated allergen challenge by Hiberix vaccine in the linseed group of animals, were always below the free fat diet control values, and in some cases the decrease was significant while sunflower oil containing diet can increase their numbers. This work showed that manipulation of dietary fat can modulate the clinical response of atopic disorders