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A leading U.K.-based pediatrician has warned that people who overuse paracetamol-based medicines such as Calpol could be putting their children's lives at risk. Reuters/Kim Kyung-Hoon

A recent study by Northwestern Medicine and the American Lung Association's Asthma Clinical Research Network has discarded the findings of a previous study that established a link between the consumption of soy supplements and a decrease in the severity of asthma attacks in patients. Following the most recent study, researchers hope to stress the importance of combating and managing asthma as an overall health issue, rather than just focusing on individual health strategies, such as increasing soy intake.

“You are what you eat, but that’s a whole constellation of foods, not just a single food or a single component of a food. Instead of focusing on supplements, we should be taking a more holistic approach,” lead author Dr. Lewis Smith said in a statement.

During the placebo-controlled study, the researchers studied the effect of soy in people with poorly controlled asthma. The team asked half of the asthmatic participants to take a soy isoflavone supplement twice a day for six months. The other half took a placebo. The research team found no evidence suggesting improvement in lung function of the patients who consumed soy supplements for half a year.

"We found that the supplement, though able to increase blood levels of the key soy isoflavone genistein, did not improve lung function, symptoms or measures of inflammation in these individuals,” Smith said in a statement. “This study highlights why it is so important to perform well-designed, placebo-controlled studies when associations are reported between specific nutrients and disease outcomes.”

The complete study has been published in the Journal of the American Medical Association.