09/07/09 Boston University School of Medicine researchers (BUSM) have observed in a study of pregnant women that consumption of at least seven servings per day of fruits and vegetables moderately reduced the risk of developing an upper respiratory tract infection (URTI). The BUSM study appears online in the journal Public Health Nutrition.

URTIs include the common cold and sinus infections, which can lead to lower respiratory problems, such as asthma or pneumonia. Even though the majority of URTIs are uncomplicated colds, identifying ways to prevent their occurrence is important because colds are the most common reason for school and work absences. Eating nutritious foods, especially fruits and vegetables, improves immunity but hadn't previously been associated with reducing the risk of URTIs in pregnant women.

BUSM researchers studied more than 1,000 pregnant women and found those who ate the most fruits and vegetables were 26 percent less likely to have URTI relative to those who ate the least amount. Neither fruit nor vegetable intake alone was found to be associated with the five-month risk of URTI. The patterns observed for total fruit and vegetable intake and either fruit or vegetable intake alone in relation to the three-month risk of URTI were consistent with those when assessing the five-month risk of URTI. Women in the highest quartile of fruit and vegetable intake had a stronger reduced three-month risk than the five-month risk of URTI. Moreover, there was a significant decreasing linear trend for the three-month risk of URTI with consumption of fruits and vegetables.

Pregnant women have been recommended to consume at least five servings of fruits and vegetables per day. This study showed that intake of higher levels, 6.71 servings per day, was associated with a moderate risk reduction for URTI.

"Pregnant women may require more fruits and vegetables than usual because of the extra demands on the body," said senior author Martha M. Werler, M.P.H., Sc.D., professor at Slone Epidemiology Center at Boston University.

This study was supported by the National Institute of Dental and Craniofacial Research. The Institute had no role in the design and conduct of the study, the collection, management, analysis and interpretation of the data, or the preparation, review and approval of the manuscript.