High soy intake improves lung function: Study

Dr Fumi Hirayama and Professor Andy Lee from Curtin University of Technology in Perth, Western Australia stated, “Chronic obstructive pulmonary disease is a leading cause of morbidity (disability due to illness) and mortality worldwide, with cigarette smoking being established as the principle risk factor.”

The study and its findings
The researchers and their team examined 278 patients, aged between 50–75 years. The patients were from six Japanese hospitals who had been diagnosed with COPD since past 4 years and 340 healthy members of the general public without the lung condition.

All the subjects were asked to fill questionnaires on demographics, lifestyle characteristics and food consumption. They also had to undergo lung function tests and were questioned about their soy intake.

Other factors taken into account were smoking, body mass index, alcohol consumption and other variables.

The participants were divided into four groups based on their daily soy consumption.

The research demonstrated that consumption of soy products gave lung function a boost. The group with the highest intake of soy (50.23g/day) was 60 percent less likely to have COPD as opposed to those in the group with the lowest intake at an average of (28.50 g/day) of soy products.

Food products rich in soy like tofu, soybean curd, soy milk were associated with improved lung function and a lower risk of respiratory symptoms, such as breathlessness.

"Soy consumption was found to be positively correlated with lung function and inversely associated with the risk of COPD,” said Hirayama about the study.

“It has been suggested that flavonoids from soy foods act as an anti-inflammatory agent in the lung, and can protect against tobacco carcinogens for smokers. However, further research is needed to understand the underlying biological mechanism,” he added.

According to the researchers, this is the first study to demonstrate the association between consumption of soy and a reduction in the risk of developing COPD. Earlier studies have found that soy foods reduce cholesterol and can alleviate menopause symptoms.

About COPD
COPD is a lung disease, encompassing chronic bronchitis and emphysema. This ailment makes it difficult to breathe and the condition deteriorates over the passage of time.

Smoking is a leading cause of COPD, accounting for nearly 90 percent of such cases. However, prolonged exposure to chemical fumes, air pollution, and other types of toxics can also cause the disease.

Nearly 12 million Americans are currently diagnosed with COPD, though there may be millions more suffering from the disease but unaware of it.