By LOIS BAKER
Contributing Editorr
New research by UB epidemiologists has suggested that Vitamin E and
a little-known vitamin called beta-cryptoxanthin found primarily in
oranges are associated with healthy lung function.
Results of the study, the first to analyze simultaneously the relationship
of vitamin C, vitamin E and certain carotenoid-class vitamins with pulmonary
health, appear in a recent issue of the American Journal of Respiratory
and Critical Care Medicine.
"Impaired lung function is associated with an increased risk of dying,"
said Holger Schünemann, research assistant professor in the Department
of Social and Preventive Medicine and lead author on the study. "Therefore,
it is important to determine the factors that could influence lung function."
Schünemann has focused his research on determining the relation of
lung function with these factors. He published an earlier study showing
that oxygen molecules known as free radicals were implicated in impaired
lung function. The current research investigated the association between
blood levels of certain antioxidant vitamins known to dispose of free
radicals and the results of lung function tests.
Previous studies on the effect of antioxidant vitamins, particularly
beta-carotene, on lung function had used dietary intake to estimate
antioxidant level and results were inconsistent. This investigation
measured blood-serum levels of vitamin C, vitamin E, retinol (a form
of vitamin A) and the carotenoids beta-crytoxanthin, lutein/zeaxanthin,
beta-carotene and lycopene in 1,616 randomly selected residents of Western
New York.
All participants performed lung-function tests to measure the volume
of air they could expel in one breath, known as forced vital capacity
(FVC), and the volume expelled in one second, called forced expiratory
volume1 (FEV1).
Analysis of antioxidant levels and lung function based on these tests
showed that lung function was better as serum levels of antioxidant
vitamins increased. Vitamin C, vitamin E, beta-crytoxanthin, lutein/zeaxanthin,
beta-carotene and retinol were positively associated with FEV1, and
beta-carotene was positively related to FVC when the vitamins were considered
individually.
However, when all vitamins were considered together, beta-crytoxanthin
and vitamin E showed the strongest relationship to the two measures
of lung function. Participants who had half of the average concentration
of these vitamins in their bloodstream showed a reduction in lung function
equivalent to 1-2 years aging of the lungs.
Retinol also was associated with pulmonary health, specifically with
FEV1.
Low levels of both vitamin C and vitamin E were associated with the
lowest results on the tests, but vitamin E had the stronger relationship.
"Our findings indicate that carotenoids and retinol, in addition to
vitamin E, may play a role in respiratory health and that the most important
carotenoid may not be beta-carotene, as previously thought," Schünemann
said. "Evaluating this association is important because persons with
reduced pulmonary function are at increased risk factor of dying from
chronic disease. Antioxidant vitamins could help reduce that risk."
Additional UB researchers on the study were Brydon J.B. Grant of the
departments of medicine and physiology; Jo L. Freudenheim, Paola Muti,
Richard W. Brown and Julie Drake, all of the Department of Social and
Preventive Medicine; Robert A. Klocke, professor and chair of the Department
of Medicine, and Maurizio Trevisan, professor and chair of the Department
of Social and Preventive Medicine.