Cruciferous vegetable intake and the risk of human cancer: epidemiological evidence

Abstract

Over several decades a number of epidemiological studies have identified the inverse associations between cruciferous vegetables and the risk of several cancers, including gastric, breast, colo-rectal, lung, prostate, bladder and endometrial cancers, via plausible physiological mechanisms. Although retrospective case-control studies have consistently reported inverse associations between the risk of these cancers and the intake of cruciferous vegetables and isothiocyanate-containing plants, current prospective cohort studies have found these associations to be weaker and less consistent. Genetic variations affecting the metabolism of glucosinolate hydrolysis products may modulate the effects of cruciferous vegetable consumption on cancer risk, which may be one of the reasons for the discrepancies between retrospective and prospective studies. In addition, methodological issues such as measurement errors of dietary exposure, misclassification, recall bias, publication bias, confounding and study design should be carefully considered in interpreting the results of case-control and cohort studies and in drawing conclusions in relation to the potential effects of cruciferous vegetables on cancers. Although recent comprehensive reviews of numerous studies have purported to show the specific protective role of cruciferous vegetables, and particularly Brassicas, against cancer risk, the current epidemiological evidence suggests that cruciferous vegetable consumption may reduce the risk only of gastric and lung cancers. However, there is at present no conclusive evidence that the consumption of cruciferous vegetables attenuates the risk of all other cancers.

The potential role of nutritional genomics tools in validating high health foods for cancer control: Broccoli as example

“…3. More comprehensive reviews on various aspects of the topic are provided elsewhere [12,[29][30][31][32].…”

Glucosinolate biosynthetic genes in Brassica rapa

“…Increasing daily intake of cruciferous vegetables is associated with reduced risk of certain cancers (Keck and Finley, 2004;Kim and Park, 2009;Tang et al, 2008;Wu et al, 2004). Chinese cabbage (B. rapa ssp.…”

Cruciferous vegetables intake and risk of prostate cancer: A meta‐analysis

“…Cruciferous vegetables are good sources of a variety of nutrients and phytochemicals that might have excellent cancer-fighting properties. 5 Epidemiological studies have shown inverse associations between consumption of cruciferous vegetables and the risk of lung, colorectal, stomach, breast and other cancers, 6 but these studies are not all clearly consistent. Over the past two decades, a number of epidemiological studies have been carried out to investigate the association of cruciferous vegetables intake with prostate cancer risk, and most of them have reported inverse, but non-significant, associations; possibly as a result of a lack of statistical power in the individual studies.…”