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Folic acid supplements and colorectal cancer risk: meta-analysis of randomized controlled trials.

Qin T, Du M, Du H, Shu Y, Wang M, Zhu L - Sci Rep (2015)

Bottom Line: We herein performed a meta-analysis based on relevant studies to reach a more definitive conclusion.Moreover, no statistical effect was identified in further subgroup analyses stratified by ethnicity, gender, body mass index (BMI) and potential confounding factors.No significant heterogeneity or publication bias was observed.

View Article: PubMed Central - PubMed

Affiliation: Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.

ABSTRACT
Numerous studies have investigated the effects of folic acid supplementation on colorectal cancer risk, but conflicting results were reported. We herein performed a meta-analysis based on relevant studies to reach a more definitive conclusion. The PubMed and Embase databases were searched for quality randomized controlled trials (RCTs) published before October 2014. Eight articles met the inclusion criteria and were subsequently analyzed. The results suggested that folic acid treatment was not associated with colorectal cancer risk in the total population (relative risk [RR] = 1.00, 95% confidence interval [CI] = 0.82-1.22, P = 0.974). Moreover, no statistical effect was identified in further subgroup analyses stratified by ethnicity, gender, body mass index (BMI) and potential confounding factors. No significant heterogeneity or publication bias was observed. In conclusion, our meta-analysis demonstrated that folic acid supplementation had no effect on colorectal cancer risk. However, this finding must be validated by further large studies.

No MeSH data available.


Related in: MedlinePlus

A flow chart of the study identification and selection.
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f1: A flow chart of the study identification and selection.

Mentions: A total of 1,229 relevant reports were retrieved from the PubMed and Embase databases, and 72 eligible studies were identified for further assessment. Eight RCTs ultimately met the inclusion criteria1819202122232425 (Fig. 1), two of which were related to the prevention of cardiovascular disease1823, four were related to the occurrence or recurrence of colorectal adenoma19202223 and two studies assessed cancer risk2124. Each study was a population-based RCT, which ensured the methodological quality of the article. All trials were placebo-controlled except for the studies by Gao et al. and Logan et al.2025. Seven studies were double-blinded studies, whereas the remaining one provided no details regarding this25. The dose of folic acid supplemented daily varied from 0.5 to 2.5 mg. Each article was of high quality based on our quality assessment, and all had received a score ranging from 3 to 5 out of a total of 5 points. Detailed characteristics of the relevant literature are presented in Table 1.


Folic acid supplements and colorectal cancer risk: meta-analysis of randomized controlled trials.

Qin T, Du M, Du H, Shu Y, Wang M, Zhu L - Sci Rep (2015)

A flow chart of the study identification and selection.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4487230&req=5

f1: A flow chart of the study identification and selection.
Mentions: A total of 1,229 relevant reports were retrieved from the PubMed and Embase databases, and 72 eligible studies were identified for further assessment. Eight RCTs ultimately met the inclusion criteria1819202122232425 (Fig. 1), two of which were related to the prevention of cardiovascular disease1823, four were related to the occurrence or recurrence of colorectal adenoma19202223 and two studies assessed cancer risk2124. Each study was a population-based RCT, which ensured the methodological quality of the article. All trials were placebo-controlled except for the studies by Gao et al. and Logan et al.2025. Seven studies were double-blinded studies, whereas the remaining one provided no details regarding this25. The dose of folic acid supplemented daily varied from 0.5 to 2.5 mg. Each article was of high quality based on our quality assessment, and all had received a score ranging from 3 to 5 out of a total of 5 points. Detailed characteristics of the relevant literature are presented in Table 1.

Bottom Line: We herein performed a meta-analysis based on relevant studies to reach a more definitive conclusion.Moreover, no statistical effect was identified in further subgroup analyses stratified by ethnicity, gender, body mass index (BMI) and potential confounding factors.No significant heterogeneity or publication bias was observed.

View Article: PubMed Central - PubMed

Affiliation: Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.

ABSTRACT
Numerous studies have investigated the effects of folic acid supplementation on colorectal cancer risk, but conflicting results were reported. We herein performed a meta-analysis based on relevant studies to reach a more definitive conclusion. The PubMed and Embase databases were searched for quality randomized controlled trials (RCTs) published before October 2014. Eight articles met the inclusion criteria and were subsequently analyzed. The results suggested that folic acid treatment was not associated with colorectal cancer risk in the total population (relative risk [RR] = 1.00, 95% confidence interval [CI] = 0.82-1.22, P = 0.974). Moreover, no statistical effect was identified in further subgroup analyses stratified by ethnicity, gender, body mass index (BMI) and potential confounding factors. No significant heterogeneity or publication bias was observed. In conclusion, our meta-analysis demonstrated that folic acid supplementation had no effect on colorectal cancer risk. However, this finding must be validated by further large studies.

No MeSH data available.


Related in: MedlinePlus