Vitamin C Helps Keep Lungs Healthy Over Time

A new study has found that high dietary intakes of vitamin C and magnesium are associated with improved lung function in adults.

In 1991, researchers in England gathered information about the diets of over 2600 men and women, aged eighteen to seventy years. They also measured respiratory symptoms, and performed a test for pulmonary function called the forced expiratory volume in one second, or FEV1. This test measures the amount of air a person can breathe out in the first second during a maximum effort to expel all the air from their lungs. People with obstructive lung disease have a reduced ability to expire air and lower FEV1 scores.

Nine years later the investigators were able to collect the same data in about half the participants in the original study population. After adjusting for smoking and other factors that could influence the results, they found a relationship between the amount of vitamin C and magnesium the participants consumed, and their FEV1 test results. Higher intakes of vitamin C and magnesium were linked to higher FEV1 values both in 1991 and 2000. In fact, a 100 mg higher average intake of vitamin C was related to a smaller decline in FEV1 values over the nine-year period. In other words, the higher intake of vitamin C over time apparently helped preserve lung function.

The authors conclude that their findings overall lend support to the idea that a diet rich in the foods that provide vitamin C is likely to be beneficial for lung health. By reducing the amount of decline in lung function over time, consuming ample amounts of these foods could lower the risk of chronic obstructive pulmonary disease or COPD-a disease that affects an estimated 15 million people and is the fifth leading cause of death in the US. COPD can be due to chronic bronchitis, emphysema, or both. Risk factors for COPD include history of smoking or passive smoke exposure, allergy and asthma, exposure to environmental pollution, recurrent respiratory illness, or a family history of chronic bronchitis or emphysema.

The take home message is to consume a sufficient amount of magnesium and vitamin C. Eating green leafy vegetables, whole grains, beans and nuts will supply ample amounts of magnesium.

Vitamin C is found in a variety of fruits and vegetables. Excellent sources of vitamin C include: orange juice, green peppers, watermelon, papaya, grapefruit juice, grapefruit, cantaloupe, strawberries, mango, broccoli, tomato juice, brussels sprouts, cauliflower, and cabbage. Vitamin C is also found in raw and cooked leafy greens such as turnip greens and spinach, canned or fresh tomatoes, potatoes, winter squash, raspberries, and pineapple. Vitamin C is sensitive to light, air, and heat. Eating fruits and vegetables raw, or minimally cooked, increases their vitamin C content.

References

1. McKeever TM, Scrivener S, Broadfield E, Jones Z, Britton J, Lewis SA. Prospective study of diet and decline in lung function in a general population. Am J Respir Crit Care Med. 165:1299-1303, 2002.