Fruits and vegetables may not have strong cancer-fighting properties, according to a recent study, but these foods remain important components of a healthful diet (J Natl Cancer Inst. 2010;102:529-537).

Patients might have been confused by findings published this spring: Dietary data from more than 30,000 Europeans with cancer demonstrated that a high intake of fruits and vegetables did not greatly reduce cancer risk. “The analysis suggested little confounding by body weight, physical activity, smoking, and several other factors that were examined,” noted the large investigative team.

In an accompanying editorial (J Natl Cancer Inst. 2010;102:510-511), Walter C. Willett, MD, DrPH, of the Harvard School of Public Health, said the findings “strongly confirms” similar results from other studies. However, he affirmed, the possibility exists that a single one or a small group of these products, or a specific substance contained in some of them, has an important protective effect. “For example, considerable evidence suggests that lycopene and tomato products reduce the risk of prostate cancer.”

Similarly, an editorial in The Lancet (2010;375:1320) reported that despite the small benefit against cancer overall, the study from which these data were drawn had previously shown fruits and vegetables to have a bigger protective effect for individual cancers such as mouth, esophagus, bowel, and lung cancers.

The editorial also acknowledged evidence indicating that antioxidants or other cancer-protective components of fruits and vegetables may be most effective when consumed in childhood or early adult life.

Finally, The Lancet editors remind readers that fruits and vegetables remain major players in cardiovascular health and staving off obesity, a risk factor for cancer.