DRAFT Australian Dietary Guidelines - Eat For Health

A5.2 Cancer
Lung cancer: The recent body of evidence suggests that consumption of fruit and vegetables is
associated with reduced risk of lung cancer (Grade C, Section 3.5 in the Evidence Report [14])
[970-972].
Colorectal cancer: Recent evidence suggests that there is no association between consumption of
fruit and vegetables together and risk of colorectal cancer (Grade C, Section 3.4 in the Evidence
Report [14]) [177, 202]. In its 2008 report, the International Agency for Research on Cancer
(IARC) also concluded that intakes of fruit and vegetables were either not associated or only
slightly associated with risk of colorectal, breast and prostate cancer [973]. However, recently
published findings from the European Prospective Investigation into Cancer and Nutrition (EPIC)
study suggest that a high consumption of fruit and vegetables is associated with reduced risk of
colorectal cancer, especially of colon cancer, but that the effect may also depend on smoking
status [974].
Ovarian cancer: It is probable that there is no association between consumption of fruit and
vegetables and risk of ovarian cancer (Grade B, Section 3.6 in Evidence Report [14]) [172, 173]. A
more recent meta-analysis has described evidence of a probable inverse relationship between
consumption of vegetables and fruit, and bladder cancer [975]. An insufficient number of studies
were found to produce an evidence statement for an association between the consumption of fruit
and vegetables and renal cancer [976-978].
Epithelial cancer: In general, comparison of the results of systematic reviews of the evidence on
diet and cancer sponsored by the World Cancer Research Fund in 1997 [586] and 2007 [42]
suggests weaker evidence of a protective effect of high intakes of fruits and vegetables against
several common epithelial cancers, with a downgrading of the association from ‘convincing’ to
‘probable.’ This is also consistent with the evidence presented in the International Agency for
Research on Cancer report [979].
Overall cancer: Analyses of prospective studies have generally failed to demonstrate consistent
evidence of a convincing association between the intake of fruits and vegetables and overall risk of
cancers [973]. However the more recent EPIC cohort study found a weak but statistically
significant inverse association between consumption of fruit and vegetables and risk of overall
cancers —a 4% lower incidence of all cancers combined for an increment of 200g total fruit and
vegetable intake per day [980].
It should also be noted that a very weak association between the consumption of fruit and
vegetables as a whole and overall cancer rates is not inconsistent with the evidence of the effects
of fruit and vegetable consumption on site-specific cancers, or the evidence that specific types of
fruit or vegetables may have an effect, particularly on the risk of site-specific cancers, and suggests
DRAFT Australian Dietary Guidelines- December 2011 174