Smokers With Adequate Vitamin C Intake Show a Preferable Pulmonary Function Test

Area of Science:

• Pulmonary Medicine
• Nutritional Science
• Epidemiology

Background:

• Chronic inflammation from cigarette smoke causes airflow obstruction.
• Ascorbic acid (vitamin C) is known to prevent oxidative damage from smoking at a cellular level.

Purpose of the Study:

• To investigate the impact of vitamin C intake on pulmonary function.
• To compare effects in established smokers versus never-smokers within a Korean population.

Main Methods:

• Utilized data from 2974 Korean adults (age > 40) from the 2008 Korea National Health and Nutrition Examination Survey IV.
• Participants were categorized by smoking status (never vs. established smoker) and vitamin C intake (higher vs. lower, based on median intake of 77.18 mg/day).
• Analyzed pulmonary function tests, including forced expiratory volume in 1 second (FEV1) and FEV1/forced vital capacity (FVC) ratio, using univariate and multiple logistic regression.

Main Results:

• Lower vitamin C intake was associated with reduced pulmonary function (FEV1 and FEV1/FVC ratio) in established smokers.
• Established smokers with lower vitamin C intake had significantly higher odds of impaired pulmonary function compared to never-smokers with higher vitamin C intake.
• Adjusted analyses confirmed that lower vitamin C intake increased the risk of poor pulmonary function, particularly in established smokers (p < 0.001).

Conclusions:

• Higher vitamin C intake correlates with better pulmonary function test results in Korean smokers.
• Maintaining adequate vitamin C levels may be beneficial for lung health in individuals exposed to cigarette smoke.