Vegetable and fruit consumption and prostate cancer risk: A cohort study in The Netherlands

Department of Epidemiology, Maastricht University, The Netherlands.
Cancer Epidemiology Biomarkers & Prevention (Impact Factor: 4.13). 09/1998; 7(8):673-80.
Source: PubMed


The association between 21 vegetables and eight fruits and prostate cancer risk was assessed in the Netherlands Cohort Study among 58,279 men of ages 55-69 years at baseline in 1986. After 6.3 years of follow-up, 610 cases with complete vegetable data and 642 cases with complete fruit data were available for analysis. In multivariate case-cohort analyses, the following rate ratios (RRs) and 95% confidence intervals (CIs) for vegetable consumption were found (comparing highest versus lowest quintile): total vegetables (RR, 0.80; CI, 0.57-1.12); prepared vegetables (RR, 0.85; CI, 0.61-1.19); and raw vegetables (RR, 0.96; CI, 0.69-1.34). For vegetables categorized in botanical groups, no associations were found except for consumption of pulses (RR, 0.71; CI, 0.51-0.98; P for trend, 0.01). The RRs for total fruit and citrus fruit were 1.31 (CI, 0.96-1.79) and 1.27 (CI, 0.93-1.73), respectively; the corresponding Ps for trend were 0.02 and 0.01, respectively. In a continuous model, no association for total fruit was observed. Individual vegetables and fruits were evaluated as continuous variables (g/day). Nonsignificant inverse associations (RRs per increment of 25 g/day) were found for consumption of kale (RR, 0.74), raw endive (RR, 0.72), mandarins (RR, 0.75), and raisins or other dried fruit (RR, 0.49). Observed positive associations were significant for consumption of leek (RR, 1.38) and oranges (RR, 1.07) and nonsignificant for sweet peppers (RR, 1.60) and mushrooms (RR, 1.49). Results in subgroups of cases were more or less consistent with the overall results. From our study, we cannot conclude that vegetable consumption is important in prostate cancer etiology, but for certain vegetables or fruits, an association cannot be excluded.

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    • "In epidemiological studies, such as case-control and cohort studies, the possible relationship between allium vegetables intake and prostate cancer risk has been investigated (Key et al., 1997; Schuurman et al., 1998; Hsing et al., 2002; Hodge et al., 2004; Galeone et al., 2006; Kirsh et al., 2007; Brasky et al., 2011; Hardin et al., 2011; Salem et al., 2011), but the findings are not all clearly consistent, possibly as a result of a lack of statistical power in the individual studies. In addition, to "
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    • "Dietary cohort studies that did not report associations with prostate cancer incidence frequently had lower lycopene and tomato intake compared with studies that report an association. A dietary cohort study based in The Netherlands between 1986 to 1992 did not report an association between tomato intake and prostate cancer incidence [22]. While this cohort took place between the same time period as the initial HPFS analysis, tomato consumption was low compared with the HPFS. "
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    • "They emerged at a time when interest in the carotenoids was fading, primarily because of the failure of supplemental b-carotene to reduce lung cancer or total cancer incidence in three randomized, placebo-controlled clinical trials (The Alpha-Tocopherol, Beta Carotene Cancer Prevention Study Group, 1994; Hennekens et al., 1996; Omenn et al., 1996). However, in another cohort study, including 58,279 men aged 55–69 years at baseline and living in the Netherlands, neither tomatoes (RR = 1.05 for a 25 g/day increase, equivalent to a serving/week) nor tomato juice (RR = 1.12 for a 25 g/day increase) were associated with decreased prostate cancer risk (Schuurman et al., 1998). The design for this study was comparable to that of the Giovannucci et al. (1995) study. "
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