There are many food-safety secrets that fast food restaurants don’t want you to know. Last week researchers revealed a potentially new secret, which suggests that eating fast food three or more times a week is linked with a higher risk of severe asthma and eczema in children and teenagers. However, they also found that frequent servings of fruit can reduce that risk.

While we easily link fast food with growing rates of childhood obesity and diabetes, many don’t associate the effects of the often-processed foods on other diseases — including autoimmune disorders. The researchers analyzed data on hundreds of thousands of children and teenagers from several countries. Their parents recorded what types of food they fed their children and tracked symptoms of asthma or eczema.

The researchers found a correlation. Teenagers who consumed at least three weekly servings of fast food saw a 39% higher risk of developing or already having severe asthma or eczema. Young children with the same eating habits had a 27% higher risk. However, they did find that those who consumed at least three servings of fruit a week were 14 percent less likely to develop asthma or eczema. They also found an 11 percent decrease in young children.

This research comes at a time when autoimmune disorders, like asthma and eczema, are on the rise in the United States and the world. The CDC reports that “the number of people diagnosed with asthma grew by 4.3 million from 2001 to 2009,” and those increasing numbers are especially apparent among African-American children.

Among eczema cases, the prevalence of eczema has doubled from 1995 to 2008. Currently 10.7% of children are estimated to have some form of eczema, which occurs disproportionately more frequently among African-American children.

Though both diseases afflict adults, they tend to first strike in childhood. Asthmatic children usually present with coughing and wheezing fits that gets worse at night. They may also complain of feeling as if a band or belt is squeezing their chest, preventing them from breathing easily. The disease later progresses to periods of “breathing” attacks that require the use of inhalers or corticosteroids for relief.

Children who frequently develop dry, reddened skin that constantly itches or burns should be checked out by their pediatrician for eczema. It can affect any part of the body, though it most commonly occurs on the face, neck, or the insides of elbows and knees. The symptoms of the disorder can be soothed with special steroid creams and oatmeal baths that relieve the itching.