Soy Intake Helps Lung Health

by | Jul 10, 2009 | 2009, Lung Health, Respiratory Health, Soy Isoflavones

Written by Greg Arnold, DC, CSCS. This Study of 278 patients with chronic obstructive pulmonary disease (COPD) demonstrated a 61% decreased risk of COPD with the highest tofu intake, a 63% decreased risk of COPD with the highest NATTO(fermented soybean) intake and a 42 % decreased risk of COPD with the highest bean sprout intake.

Chronic Obstructive Pulmonary Disease (COPD) is defined as “a slowly progressive disease of the airways that is characterized by a gradual loss of lung function” and is the fifth-leading cause of death worldwide (1). While 12.1 million adults aged 25 and older were diagnosed with COPD in 2001, it’s estimated that another 24 million adults have evidence of impaired lung function. In 2001 alone, COPD cost our healthcare system over $32 billion (2)

Now a new study (3) has found that soy may also help with lung health. In the study, 278 patients between the ages of 50 and 75 diagnosed with COPD within the previous 4 years underwent lung function tests (called “spirometry” (4)). They provided information on their diet and lifestyle through a 138-item questionnaire (5) whose reliability has been proven in previous research (6). These patients’ results were compared to 340 patients without COPD. The researchers found that soy intake among those without COPD was nearly 25% higher than those with COPD (60 grams vs. 44.84 grams per day). When comparing the highest (> 75.83 grams per day) versus lowest (< 30.43 grams per day) soy intake per day, a 60% reduced risk of COPD was evident.

When individual soy-containing foods were examined (comparing the highest to lowest intakes), there was a 61% decrease with the highest tofu intake (>28.69 vs <7.53 grams per day), a 63% decreased risk with the highest Natto (fermented soybean) intake (compared to the lowest) (>39.31 vs. <10.70 grams per day), and a 42% decreased intake with the highest bean sprout intake (>5.27 vs. <1.67 grams per day). For the researchers, “Increasing soy consumption was associated with a decreased risk of COPD and breathlessness.”

Source: Hirayama, Fumi, et al. “Soy consumption and risk of COPD and respiratory symptoms: a case-control study in Japan.” Respiratory research 10.1 (2009): 56.

© 2009 Hirayama et al; licensee BioMed Central Ltd. Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0)

Click here to read the full text study.

Posted July 10, 2009.

References:

  1. Pauwels RA, Rabe KF. Burden and clinical features of chronic obstructive pulmonary disease (COPD). Lancet 2004; 364:613-620.
  2. “Chronic Obstructive Pulmonary Disease” posted on the National Heart, Lung, and Blood Institute Website.
  3. Hirayama F.  Soy consumption and risk of COPD and respiratory symptoms: a case-control study in Japan.  Res Res 2009; 10:56-63.
  4. “Pulmonary Function Tests” posted on The Medline Plus website.
  5. Ishihara J.  Demographics, lifestyles, health characteristics, and dietary intake among dietary supplement users in Japan. Int J Epidemiol. 2003, 32(4):546-553.
  6. Ishihara J.  Validity and reproducibility of a self-administered food frequency questionnaire in the JPHC study cohort II: study design, participant profile and results in comparison with cohort I. J Epidemiol. 2003, 13(1 Suppl):S134-S147.