Carotenoids may improve lung function

According to a new US study, increased blood carotenoid concentrations may be associated with a slower rate of age-related lung function decline.

In the observational trial, the long-term association between serum carotenoid (e.g., beta-carotene, lutein/ zeaxanthin and lycopene) concentrations and the development of lung function was analyzed for a period of 20 years in 2701 men and women between the ages of 18 and 30 (1). Lung function testing was conducted at years 0, 2, 5, 10 and 20; serum carotenoids were assayed at years 0 and 15 and diet was assessed at years 0 and 20. The study results showed that higher provitamin A carotenoid (e.g., beta-carotene) concentrations at years 0 and 15 were associated with a significantly slower rate of decline from maximum observed lung function. In addition, the results indicated a non-significant association between provitamin A carotenoid concentrations and maximum lung function.

The researchers concluded that increased blood carotenoid levels may support the prevention of age-related lung function decline. In addition, a healthy lifestyle and factors that influence serum carotenoid concentrations, such as interindividual variations in carotenoid metabolism, may play a role. On the other hand, the role of provitamin A carotenoids in lung development would need to be investigated in more detail in future studies.

Reduced lung function, even in asymptomatic and otherwise healthy adults, is associated with cardiovascular disease and overall mortality in the general population. Increased oxidative stress and inflammation have been negatively associated with lung function. Thus, antioxidant carotenoids may have a protective role in lung function decline. Many cross-sectional epidemiologic studies have shown positive associations between higher lung function and higher intakes of carotenoid (2, 3) and higher serum concentrations of carotenoids (4, 5). A randomized controlled trial of carotenoid supplementation showed that increases in beta-carotene and vitamin A concentrations were associated with improvements in lung function in current and former smokers (6).

1. Thyagarajan B. et al. Serum carotenoid concentrations predict lung function evolution in young adults: the Coronary Artery Risk Development in Young Adults (CARDIA) Study. Am J Clin Nutr. Online publication September 2011.
2. Schünemann H. J. et al. Lung function in relation to intake of carotenoids and other antioxidant vitamins in a population-based study. Am J Epidemiol. 2002; 155:463–471.
3. Hu G. and Cassano P. A. Antioxidant nutrients and pulmonary function: the Third National Health and Nutrition Examination Survey (NHANES III). Am J Epidemiol. 2000; 151:975–981.
4. Schünemann H. J. et al. The relation of serum levels of antioxidant vitamins C and E, retinol and carotenoids with pulmonary function in the general population. Am J Respir Crit Care Med. 2001; 163:1246–1255.
5. Guénégou A. et al. Serum carotenoids, vitamins A and E, and 8 year lung function decline in a general population. Thorax. 2006; 61:320–326.
6. Chuwers P. et al. The protective effect of beta-carotene and retinol on ventilatory function in an asbestos-exposed cohort. Am J Respir Crit Care Med. 1997; 155:1066–1071.