Meta-analysisAssociation between fruit and vegetable intake and risk for glioma: A meta-analysis
Introduction
Glioma is the most common primary brain tumor, occurring most frequently in adults and accounting for approximately 70% of adult brain malignancies [1], [2]. It has an incidence of 5 to 10 cases per 100 000 [1]. Evidence has suggested that a genetic predisposition and ionizing radiation are established risk factors for brain tumors [3], [4], [5]. Additionally, other potential risk factors include exposure to environmental chemical carcinogens, such as chemical agents and, among dietary factors, exposure to N-nitroso compounds [1], [3]. Due to the highly invasive character of glioma, complete resection is difficult to achieve [6]. Thus, prevention of glioma progression has become an important strategy for fighting the disease [7].
The intake of fruit and vegetables has long been associated with a decreased risk for various diseases [8], [9]. The suggested mechanisms for the major role of vegetables and fruit include modulation of DNA methylation; protection from and repair of DNA damage; promotion of apoptosis; and induction of detoxifying phase II enzymes [10]. To date, a number of epidemiologic studies have explored the relationship between fruit and vegetable intake and the risk for glioma. However, results are not consistent [11], [12], [13], [14]. Thus, to better characterize this issue, we conducted a comprehensive meta-analysis to evaluate the evidence from observational studies on the association between vegetable and fruit intake and the risk for glioma by summarizing it quantitatively with a meta-analysis approach.
Section snippets
Search strategy
A comprehensive search was conducted for available articles published in English or Chinese using the databases of PubMed, Web of Knowledge, and Wan Fang Med Online up to January 2014 and by hand-searching the reference lists of the computer-retrieved articles. The following search terms were used: glioma AND (neoplasm OR carcinoma OR cancer) combined with nutrition OR diet OR lifestyle OR fruit OR vegetable. Two investigators searched articles and reviewed all retrieved studies independently.
Search results and study characteristics
The search strategy identified 312 articles from PubMed, 11 from Wan Fang Med Online, and 432 from the Web of Knowledge. Twenty-nine articles were reviewed in full after reading the title/abstract. By studying reference lists, we identified two additional articles. Sixteen of these 31 articles were subsequently excluded from the meta-analysis for various reasons. Hence, 12 articles [12], [13], [14], [22], [23], [24], [25], [26], [27], [28], [29], [30] with 15 studies (1 prospective study and 14
Discussion
Findings from this meta-analysis suggested that the intake of vegetables might have a protective effect on glioma (pooled RR, 0.775; 95% CI, 0.688–0.872) for overall data and all subgroup analyses. The intake of fruit might have a protective effect on glioma only in an Asian population (RR, 0.573; 95% CI, 0.346–0.947) and hospital-based case–control studies (RR, 0.586; 95% CI, 0.398–0.863), but not in other subgroups.
Previous meta-analyses have suggested that a favorable effect was found
Conclusion
In summary, results from this meta-analysis suggested that the intake of vegetables might have a protective effect on glioma. The intake of fruit may have a protective effect on glioma in an Asian population, which needs to be confirmed.
References (40)
- et al.
Primary brain tumours in adults
Lancet
(2012) - et al.
Microregional extracellular matrix heterogeneity in brain modulates glioma cell invasion
Int J Biochem Cell Biol
(2004) - et al.
Prospective study of intake of fruit, vegetables, and carotenoids and the risk of adult glioma
Am J Clin Nutr
(2007) - et al.
An international case-control study of adult diet and brain tumor risk: a histology-specific analysis by food group
Ann Epidemiol
(2009) - et al.
Meta-analysis in clinical trials
Control Clin Trials
(1986) - et al.
Meta-analysis of genetic association studies
Trends Genet
(2004) - et al.
Malignant gliomas in adults
N Engl J Med
(2008) Epidemiology of brain tumors
Methods Mol Biol
(2009)- et al.
Quantitative assessment of the association between +61 A>G polymorphism of epidermal growth factor gene and susceptibility to glioma
Tumour Biol
(2014) - et al.
Three polymorphisms of DNA repair gene XRCC1 and the risk of glioma: a case-control study in northwest China
Tumour Biol
(2014)
Association between ERCC1 C8092 A and ERCC2 K751Q polymorphisms and risk of adult glioma: A meta-analysis
Tumour Biol
Intake of fruit and vegetables and risk of esophageal squamous cell carcinoma: a meta-analysis of observational studies
Int J Cancer
Fruit and vegetable intake and risk of cardiovascular disease
Proc Nutr Soc
Diet and cancer prevention
Oncogene
Links between private habits, psychological stress and brain cancer: A case-control pilot study in France
J Neurooncol
Inverse association of antioxidant and phytoestrogen nutrient intake with adult glioma in the San Francisco Bay area: a case-control study
BMC Cancer
Quantifying heterogeneity in a meta-analysis
Stat Med
Measuring inconsistency in meta-analyses
BMJ
Controlling the risk of spurious findings from meta-regression
Stat Med
Operating characteristics of a rank correlation test for publication bias
Biometrics
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2021, Trends in Food Science and TechnologyCitation Excerpt :When increasing the intake of fruit to three servings per week reduced the risk of developing gastric cancer by 52% (Poorolajal et al., 2020). However, there was no association found between fruit intake and the occurrences of glioma (Li, 2014), pancreatic cancer (Koushik et al., 2012; Zhao et al., 2018), liver cancer (Guo et al., 2019), hepatocellular carcinoma (Yang et al., 2014), premenopausal-breast cancer (Farvid et al., 2021), thyroid cancer (Liu & Lin, 2014), bladder cancer (Xu et al., 2015), prostate cancer (Meng et al., 2014), endometrial cancer (Bandera et al., 2007), ovarian cancer (Khodavandi et al., 2021), non-Hodgkin lymphoma (NHL) (Sergentanis et al., 2018), diffuse large B-cell lymphoma (Sergentanis et al., 2018), small lymphocytic lymphoma/chronic lymphocytic leukemia (Sergentanis et al., 2018), acute myeloid leukemia (Sergentanis et al., 2018), or multiple myeloma (Sergentanis et al., 2018) (Table 3). Fruit intake has also been shown to reduce the mortality from ovarian cancer (Hurtado-Barroso et al., 2020), but no significant associations between fruit intake and total cancer mortality (Wang, 2014), head and neck cancer mortality (Hurtado-Barroso et al., 2020), NHL mortality (Hurtado-Barroso et al., 2020), or breast cancer-specific mortality (Peng et al., 2017) were found (Table 1).
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2021, Clinical NutritionCitation Excerpt :In accordance with our findings, a previous case–control study reported that higher adherence to the Dietary Approaches to Stop Hypertension, which encourages the consumption of healthy food items including higher consumption of nuts and legumes, vegetables, fruits, and whole grains, was associated with a 72% decreased odds of glioma [46]. In addition, combined findings of 17 observational studies about the consumption of fruit and vegetables revealed a lower risk of glioma among those with the highest intake [11]. Another meta-analysis that examined the association between fish intake and risk of brain tumors demonstrated a protective role for fish intake against brain cancer [47].
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