A perceived increase in allergies among children in the industrialized world has been blamed on everything from environmental pollutants to sanitizing products. Now, a team of researches from Finland suggests that diet may play a role.
Their study, published in a recent issue of the journal Allergy, found that children who eventually developed allergies ate less butter and more margarine compared with children who did not develop allergies. The allergic children also tended to eat less fish, although this dietary difference was less significant. While it is too soon to make dietary recommendations aimed at lowering the risk of allergies, the findings provide evidence of a link between certain dietary fats and allergic diseases such as asthma, according to Dr. Teija Dunder and colleagues at the University of Oulu.
The study is not the first to suggest that certain types of fatty acids may play a role in the onset of allergic diseases. Polyunsaturated fats like those in margarine are thought to promote the formation of prostaglandin E2, a substance that promotes inflammation and causes the immune system to release a protein that triggers allergic reactions.
A diet higher in unsaturated fats and low in saturated fats such as those in butter is more healthful in general. But the growing emphasis on achieving this fat balance has been blamed in some research for the increasing rates of childhood allergies, the report indicates. At the same time, however, studies have suggested the unsaturated fats found in certain types of fish may protect against allergic disease.
This study, according to Dunder’s team, supports the overall idea that dietary fat somehow affects allergy risk. “Our results support the hypothesis that the quality of the fat consumed in the diet is important for the development of allergic diseases in children,” the study authors write. “The possibility of preventing allergic diseases by supplementation or by changing the fatty acid composition of the diet of young children remains to be tested by clinical trials.”
The investigators reviewed data from 462 children aged 3 to 18 in 1980 and from 308 children in 1986, and followed the children for 9 years. In 1980, children with atopic dermatitis–a common allergic reaction that causes itchy skin–consumed about 8 grams of margarine for every 1,000 calories, compared with roughly 6 grams among children without the condition.
Children with atopic dermatitis also consumed about 9 grams of butter per 1,000 calories, while those without the allergy downed more than 11 grams of butter, on average. In other findings, the ratio of polyunsaturated to saturated fat was higher and the percentage of myristic acid, an indicator of saturated fat intake, was significantly lower in children with atopic dermatitis in 1980.
On the other hand, children with the allergy also had lower levels of polyunsaturated fats found in fish–although their fish intake was similar to that of the other children. High fish intake, the researchers note, has been linked to lower rates of asthma. The current study supports the idea that the fat composition of children’s diets may influence their allergy risk, Dunder and colleagues conclude.