Vitamin E in Soya Beans and Canola Oil Causes Lung Problems and Asthma: Study

Vitamin E-rich oils can cause lung problems and breathing difficulties, according to a study.

Canola, soya beans and corn oils are rich sources of vitamin E in the form of gamma-tocopherol. Researchers from the Northwestern University found that increased consumption of gamma-tocopherol is associated with decreased lung function, inflammation and even asthma. While alpha-tocopherol, the other form of vitamin E found in olive and sunflower oil helps improve lung health.

The current study used data of 4,526 people who took part in the Coronary Artery Risk Development in Young Adults Study (CARDIA) and noted lung functioning and capacity once in every four years for nearly two decades. Experts recorded tocopherol in the blood samples of the participants five times in 15 years. The tocopherol readings from blood plasma accurately helps determine the amount of vitamin E ingested by the body through food and supplements.

It was observed that very high levels of gamma-tocopherol that equals 10 micromolar in every one liter blood plasma reduced lung functioning by 10 to 17 percent. About 10 percent of lung capacity to function results in asthma like condition where people experience serious trouble breathing.

"Considering the rate of affected people we found in this study, there could be 4.5 million individuals in the U.S. with reduced lung function as a result of their high gamma-tocopherol consumption," said Joan Cook-Mills, study author and associate professor of medicine in allergy and immunology at Northwestern University Feinberg School of Medicine in a news release.

The number of people affected with asthma has increased in the last 40 years and this is mainly attributed to the diet trend involving, soya bean, canola and corn oils that are assumed to benefit the heart.

According to the data by the U.S. Centers for Disease Control and Prevention, about 18.7 million American adults and 6.8 million children have asthma. The overall gamma-tocopherol levels in the blood plasma of an average American is four to five times higher than that of a European or Scandinavian person.

"People in countries that consume olive and sunflower oil have the lowest rate of asthma and those that consume soybean, corn and canola oil have the highest rate of asthma," Cook-Mills said. "When people consume alpha-tocopherol, which is rich in olive oil and sunflower oil, their lung function is better."

More information is available online in the journal Respiratory Research.