Plasma vitamin C concentrations and risk of incident respiratory diseases and mortality in the European Prospective Investigation into Cancer-Norfolk population-based cohort study

• Published in: European journal of clinical nutrition Vol. 73; no. 11; pp. 1492 - 1500
• Main Authors: Myint, Phyo Kyaw, Wilson, Andrew M., Clark, Allan B., Luben, Robert N., Wareham, Nicholas J., Khaw, Kay-Tee
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.11.2019; Nature Publishing Group
• Subjects: 692/308; 692/499; Adult; Aged; Ascorbic acid; Ascorbic Acid - blood; Bacterial pneumonia; Cancer; Clinical Nutrition; Cohort analysis; Confidence intervals; Epidemiology; Fatalities; Female; Fruits; Health aspects; Health risk assessment; Health risks; Humans; Illnesses; Incidence; Internal Medicine; Investigations; Lung cancer; Lung diseases; Male; Medicine; Medicine & Public Health; Metabolic Diseases; Middle Aged; Mortality; Oncology, Experimental; Pneumonia; Population studies; Population-based studies; Prospective Studies; Public Health; Quartiles; Respiratory diseases; Respiratory Tract Diseases - blood; Respiratory Tract Diseases - epidemiology; Respiratory Tract Diseases - mortality; Risk Factors; Risk management; Smoking; Statistical models; Vegetables; Vitamin C; United Kingdom
• ISSN: 0954-3007; 1476-5640; 1476-5640
• DOI: 10.1038/s41430-019-0393-1

Background/Objectives Cancerous and non-cancerous respiratory diseases are common and contribute significantly to global disease burden. We aim to quantify the association between plasma vitamin C concentrations as an indicator of high fruit and vegetable consumption and the risk of incident respiratory diseases and associated mortality in a general population. Subjects/Methods Nineteen thousand three hundred and fifty-seven men and women aged 40–79 years without prevalent respiratory diseases at the baseline (1993–1997) and participating in the European Prospective Investigation into Cancer (EPIC)-Norfolk study in the United Kingdom were followed through March 2015 for both incidence and mortality from respiratory diseases. Results There were a total of 3914 incident events and 407 deaths due to any respiratory diseases (excluding lung cancers), 367 incident lung cancers and 280 lung cancer deaths during the follow-up (total person-years >300,000 years). Cox's proportional hazards models showed that persons in the top quartiles of baseline plasma vitamin C concentrations had a 43% lower risk of lung cancer (hazard ratio (HR) 0.57; 95% confidence interval (CI): 0.41–0.81) than did those in the bottom quartile, independently of potential confounders. The results are similar for any non-cancerous respiratory diseases (HR 0.85; 0.77–0.95), including chronic respiratory diseases (HR 0.81; 0.69–0.96) and pneumonia (HR 0.70; 0.59–0.83). The corresponding values for mortality were 0.54 (0.35–0.81), 0.81 (0.59–1.12), 0.85 (0.44–1.66) and 0.61 (0.37–1.01), respectively. Confining analyses to non-smokers showed 42% and 53% risk reduction of non-smoking-related lung cancer incidence and death. Conclusions Higher levels of vitamin C concentrations as a marker of high fruit and vegetable consumption reduces the risk of cancerous and non-cancerous respiratory illnesses including non-smoking-related cancer incidence and deaths.