You probably know at least one child who suffers from food allergies. Scientists have been studying why so many children face this problem, and now they’ve identified another cause: secondhand smoke. Secondhand smoke comes from a burning tobacco product and the smoke exhaled by someone smoking.

Secondhand smoke from tobacco products is a complex mixture of thousands of different chemicals. Hundreds of these chemicals are toxic and at least 70 are carcinogenic. Even brief exposure to these chemicals is not considered safe. It can lead to molecular changes that cause cancer and changes in the cells that line blood vessels and alter platelets in the blood, which can increase the chances of a heart attack. An estimated 2.5 million nonsmoking Americans have died from exposure to secondhand smoke since the mid-1960s. Smoking during pregnancy is especially deadly, leading to 1,000 or more infant deaths annually.

We already know that secondhand smoke can have serious and long-term effects on a child’s health. Exposed children are known to get sick more frequently. Children are more likely to experience wheezing and coughing, and those with asthma are subject to more frequent and severe attacks, which can become life-threatening. They show a reduction in lung growth during their development, and experience more bronchitis, pneumonia and other respiratory and ear infections. Secondhand smoke can also lead to sudden infant death syndrome in children.

A Swedish study published last year studied how exposure to secondhand smoke in children can lead to increased risks of sensitization to food allergens and the development of food allergies. The common foods children are allergic to include cow’s milk, eggs, wheat, peanuts and fish. This large study enrolled more than 3,300 children, who were followed from birth until they were 16-years-old. The study used periodic questionnaires to track secondhand smoke exposure and symptoms of allergic disease. This study did not include children who were exposed during pregnancy. This made it easy to determine the effects of secondhand smoke.

Results from this study clearly showed that secondhand smoke exposure resulted in increased sensitization of children starting at age four. This sensitization to food allergens persisted into adolescence. Food allergies can have a tremendous impact on children’s lives, and the health care costs associated with managing this long-term health concern are significant.

How can you protect children from the health effects of secondhand smoke? First, do not smoke around your children, where you live or in your car. Second, do not permit anyone else to do so either. Third, choose babysitters, daycares and schools that are smoke free. If you suspect your child is suffering any health effects due to secondhand smoke, food allergens or otherwise, see your pediatrician.

It sounds logical, but consider the many smokers who come in contact with a child throughout their development and the complications of creating a smoke-free environment.

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