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Obesity isn’t the only potential toll that dinner from the drive-thru may have on your health.

It’s not just your waistline that may pay a price for eating fast food meals three or more times a week, but your immune system as well. According to a study published in the journal Thorax, fast food fare is linked to an increased risk of asthma, eczema and rhinitis among kids and teens. The study also found that eating fruit could protect against these disorders among all age groups.

A group of European researchers analyzed data from participants in the International Study of Asthma and Allergies in Childhood (ISAAC), which included more than 319,000 teens ages 13 to 14 from over 50 countries, and more than 181,000 kids ages six to seven from 31 countries.

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Both the participants and their parents answered questions about how often and how severely they experienced symptoms of asthma, eczema and rhinitis–like wheezing, runny nose and itchy and watery eyes. They were also asked about their diets, and how often they ate foods ranging from vegetables to fast food burgers.

Eating fast food meals at least three times a week was linked to a 39% increased risk of severe asthma in teenagers and a 27% increased risk among children between ages six and seven. Fruit, on the other hand, seemed to have the opposite effect on asthma symptoms; three or more servings of fruit was associated with a 11% decrease in severe symptoms in teens and a 14% drop in severity of suffering in kids.

The scientists accounted for other potential factors that could explain the difference in incidence of the disorders, but fast food remained the only food that showed similar associations among both the younger children and the teens, suggesting a strong link between the fatty and processed foods and respiratory problems.

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“This is the largest study to date on allergies in people around the world, and the findings are remarkably consistent when it comes to looking at specific regions of the world and within affluence and sex,” says study author Hywel Williams, a professor at the Centre for Evidence Based Dermatology at the University of Nottingham. “If true, our findings have big public health implications given that these types of allergies are on the rise and fast food is so popular.”

Although the results don’t confirm a cause and effect relationship, previous studies have shown that saturated fats can influence immunity, which in turn can make children’s immune systems more sensitive to the various allergens behind allergies such as rhinitis and that drive asthma and eczema. The fact that the fruit eaters seemed to be protected from these conditions also supports this idea, since fruits are typically high in antioxidants that can fight cell damage and boost immune health. Fast food may be convenient, but the latest data suggests that the price for that ease may be getting higher.