Allium Vegetables and Risk of Prostate Cancer: Evidence from 132,192 Subjects

Abstract

Objective: To evaluate the relationship between allium vegetable intake and risk of prostate cancer. Methods: A systematic literature search up to May 2013 was carried out in PubMed, EMBASE, Scopus, Web of Science, Cochrane register, and Chinese National Knowledge Infrastructure (CNKI) databases, and the references of retrieved articles were also screened. The summary relative risks with 95% confidence interval for the highest versus the lowest intake of allium vegetables were calculated. Heterogeneity and publication bias were also evaluated. Results: A total of nine epidemiological studies consisting of six case-control and three prospective cohort studies were included. We found a significantly decreased risk of prostate cancer for intake of allium vegetables (OR = 0.82, 95% CI 0.70, 0.97). Moreover, in the subgroup analysis stratified by allium vegetable types, significant associations were observed for garlic (OR = 0.77, 95% CI 0.64-0.91) but not onions (OR = 0.84, 95% CI 0.62-1.13). Conclusions: Allium vegetables, especially garlic intake, are related to decreased risk of prostate cancer. Because of the limited number of studies, further well-designed prospective studies are warranted to confirm the findings of our study.

Garlic consumption and colorectal cancer risk in man: a systematic review and meta-analysis

“…Similarly to our results, a preventive effect of garlic on gastric cancer was observed in three hospital-based case-control studies (OR = 0·57; 95 % CI 0·34, 0·80) and in eight population-based case-control studies (OR = 0·52; 95 % CI 0·37, 0·67), while one cohort study showed an increased risk (OR = 1·28; 95 % CI 0·45, 3·66) (39) . Furthermore, the results obtained on prostate cancer were similar to our results in showing that meta-analysis from the case-control studies suggested a significant reduction in risk (OR = 0·77; 95 % CI 0·64, 0·91) while the results from the cohort studies were null (OR = 0·96; 95 % CI 0·89, 1·05) (40) . Several mechanisms have been suggested to participate in Table 2 Results of stratified analysis on the basis of study type, cancer site and sex 0·655 (23,(25)(26)(27)(28)31,33,34) F, females; M, males.…”

Epidemiology of Prostate Cancer

“…Several studies suggest that consumption of vegetables and fruit are associated with a lower risk of developing prostate cancer (Liu et al, 2012;Zhou et al, 2013). Askari et al (2014) conducted a case-control study to evaluate the association between consumption of vegetables and fruit and prostate cancer.…”

A Western Dietary Pattern Increases Prostate Cancer Risk: A Systematic Review and Meta-Analysis

“…It was observed a significant increment of PC risk associated with Carbohydrate pattern (OR=1.64; 95% CI: 1.35, 2.00; p=0.0001), in the absence of heterogeneity (I 2 =0.00%, p=0.393) ( Table 3). The analysis was performed when a number of data ≥3 were available; 2 The risk estimates ware calculated using the random-effect model; 3 In brackets are indicated the number of articles included in the analysis; 4 Analysis was performed on case-control and cohort studies combined together;…”

“…Indeed, significant preventive effects have been found for the intake of allium vegetables [4], carrots and coffee [5,6], whereas inconsistent correlation has been observed between PC risk and consumption of tomato and lycopene [7,8], tea [9], fruit and vegetables [10], fiber [11], fat [12], red meat, processed meat and seafood [13]. On the other hand, dairy products, calcium and eggs seem to act as risk factors for PC [13,14].…”