Asthma study hints at benefits of soy for tackling airway inflammation
Scientists in Japan investigating new treatments for asthma have made a promising discovery, finding a fermented soybean product can help temper inflammation associated with the condition in animal models. The food supplement appeared to induce these anti-inflammatory effects by acting on key cells in the bronchi, and raises the prospect of a complementary means of managing the condition that doesn't involve steroid inhalants.
The idea that a diet high in soy products can help alleviate the severity of asthma symptoms is one scientists have been exploring for some time. One notable example published in 2015, called the Study of Soy Isoflavones in Asthma (SOYA) trial, sought to build on earlier indications that these supplements could reduce severity in patients with poorly controlled asthma, but the multi-year study came to no such conclusion. Follow-up investigations since, however, found they can in fact benefit asthma sufferers with very specific genetic mutations.
“The relationship between soy intake and allergic diseases has been epidemiologically reported in the past, suggesting that the components of soy may have some anti-allergic effects," says Hideaki Kadotani, first author of this new study, from Osaka City University.
The researchers explored this idea further by feeding mouse models of asthma a diet enriched with a fermented soy product called ImmuBalance, with mice on a normal diet used as controls. In the ImmuBalance group, the scientists observed a significant reduction in white blood cells linked to asthma called eosinophils, along with the suppression of inflammation in the bronchi and the production of mucus. Further, the scientists reported reductions in proteins and antibodies associated with inflammation, as compared to mice on a normal diet.
“It was reported that imbalances in the gut microbiota may be involved in immune system and allergic diseases, and fermented dietary fiber, like that found in soy, might have beneficial effects in allergic asthma models.” says Associate Professor Kazuhisa Asai, supporting author of the study.
Further work is needed to explore how these effects seen in mice on soy-enriched diets might translate to human sufferers of asthma, but the scientists believe the findings do show a potential path to more comfortable management of the condition in future.
“In clinical practice, steroid inhalants are the basis of asthma treatments, yet they are known to have adverse side effects“, says study author Professor Tomoya Kawaguchi. “Our results suggest that the intake of fermented soybean products should be recommended as a complementary coping strategy to asthma with fewer side effects.”
The research was published in the journal Nutrients.
Source: Osaka City University