Guidelines Dietary - Eat For Health

Appendix JStudies examining the health effects of intake of fruit andvegetables togetherThe literature includes studies that have investigated the effect of consumption of fruit and vegetables together.This evidence clearly confirms the positive health effects of consuming vegetables and fruits, particularly inreducing the risk of cardiovascular disease, but also in reducing risk of obesity and some cancers. It is compiledas an Appendix to aid the conciseness of Chapter 2.Cardiovascular disease, type 2 diabetes and excess weightThere is evidence regarding a probable association between the consumption of each additional daily serve of fruitand vegetables and reduced risk of coronary heart disease (Grade B; Evidence Report, Section 3.1). 362-364,367,1105Similarly, recent evidence supports a probable association between consumption of each additional daily serve offruit and vegetables and a reduced risk of stroke (Grade B; Evidence Report, Section 3.2). 362,363 Consuming morethan five serves of fruit and vegetables a day was found to reduce the risk of stroke by 26% (fruit serve was 80g andvegetables 77 g), 363 and consuming each additional serve of fruit and vegetables (of average serve size 106 g) reducedthe risk of stroke by 5%. 362 These results are consistent with those presented in the literature reviews to inform therecent review of the Dietary Guidelines for Americans, 2010 which found that ‘consistent evidence suggests at leasta moderate inverse relationship between vegetable and fruit consumption with myocardial infarction and stroke, withsignificantly larger, positive effects noted above five serves of vegetables and fruits per day’. 198In the literature reviews to inform the revision of the Dietary Guidelines for Americans, 2010, the evidence for anassociation between increased fruit and vegetable intake and reduced risk of excess body weight was found to bemodest, with a trend towards decreased weight gain over five or more years in middle adulthood associated withincreased fruit and vegetable intake. However no conclusions could be drawn from the evidence of efficacy ofincreased fruit and vegetable consumption in weight loss diets. 198 In children and adolescents, the limited body ofevidence from longitudinal studies suggested that greater intakes of fruits and/or vegetables may protect againstincreased adiposity. 198CancerLung cancer: The recent body of evidence suggests that consumption of fruit and vegetables is associated withreduced risk of lung cancer (Grade C; Evidence Report, Section 3.5). 1106-1108Colorectal cancer: Recent evidence suggests that there is no association between consumption of fruit andvegetables together and risk of colorectal cancer (Grade C; Evidence Report, Section 3.4). 389,410 In its 2008 report,the International Agency for Research on Cancer (IARC) also concluded that intakes of fruit and vegetables wereeither not associated or only slightly associated with risk of colorectal, breast and prostate cancer. 1109 However,recently published findings from the European Prospective Investigation into Cancer and Nutrition (EPIC) studysuggest 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. 1110Ovarian cancer: It is probable that there is no association between consumption of fruit and vegetables andrisk of ovarian cancer (Grade B; Evidence Report, Section 3.6). 384,385 A more recent meta-analysis has describedevidence of a probable inverse relationship between consumption of vegetables and fruit, and bladder cancer. 1111An insufficient number of studies were found to produce an evidence statement for an association between theconsumption of fruit and vegetables and renal cancer. 1112-1114Epithelial cancer: In general, comparison of the results of systematic reviews of the evidence on diet and cancersponsored by the WCRF in 1997 1115 and 2007 43 suggests weaker evidence of a protective effect of high intakesof 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 IARC report. 1116Overall cancer: Analyses of prospective studies have generally failed to demonstrate consistent evidence of aconvincing association between the intake of fruits and vegetables and overall risk of cancers. 1109 However themore recent EPIC cohort study found a weak but statistically significant inverse association between consumptionof fruit and vegetables and risk of overall cancers – a 4% lower incidence of all cancers combined for an incrementof 200g total fruit and vegetable intake per day. 1117140EAT FOR HEALTH – australian dietary guidelinesNational Health and Medical Research Council