The impact of capsaicin intake on risk of developing gastric cancers: a meta-analysis.
BACKGROUND
Reported associations of capsaicin with gastric cancer development have been conflicting. Here, we examine 10 published articles that explore these associations using 2,452 cases and 3,996 controls.


METHODS
We used multiple search strategies in MEDLINE through PubMed to seek for suitable articles that had case-control design with gastric cancer as outcome.


RESULTS
The outcomes of our study shows protection (odds ratio [OR] 0.55, P = 0.003) and susceptibility (OR 1.94, P = 0.0004), both significant with low and medium-high intake of capsaicin, respectively, although under relatively heterogeneous conditions (P(heterogeneity) = <0.0001). Outlier analysis resulted in loss of overall heterogeneity (P = 0.14) without affecting the pooled ORs. Among the subgroups, low intake elicited protection in both Korean (OR 0.37) and Mexican (OR 0.63) populations while high intake rendered these subgroups susceptible (OR 2.96 and OR 1.57, respectively). These subgroup values were highly significant (P = 0.0001-0.01) obtained in heterogeneous conditions (P(heterogeneity) < 0.0001-0.04). The homogeneous (P(heterogeneity) = 0.27-0.37) H. pylori (OR 0.60 and 1.69) effects were highly significant (P < 0.001) in the low and medium-high intake analyses, respectively. Given outcomes from the tests of interaction, high capsaicin intake is significantly different from the protection that low consumption offers.


CONCLUSIONS
This meta-analysis implies moderation in capsaicin consumption in order to derive its protective benefits.
School of Natural Sciences and Nursing, Saint Louis University, 2600, Baguio City, Philippines.
Noel
N
Pabalan
Hamdi
H
Jarjanazi
Hilmi
H
Ozcelik
D000818:Animals; D016588:Anticarcinogenic Agents / Q000008:administration & dosage / Q000009:adverse effects* / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D001208:Asia / Q000453:epidemiology; D002211:Capsaicin / Q000008:administration & dosage / Q000009:adverse effects* / Q000494:pharmacology; D002212:Capsicum; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic / Q000187:drug effects; D004032:Diet; D004198:Disease Susceptibility; D004305:Dose-Response Relationship, Drug; D005753:Gastric Mucosa / Q000187:drug effects; D005756:Gastritis / Q000453:epidemiology / Q000382:microbiology; D005786:Gene Expression Regulation / Q000187:drug effects; D016481:Helicobacter Infections / Q000453:epidemiology; D016480:Helicobacter pylori / Q000472:pathogenicity; D006801:Humans; D008019:Life Style; D008296:Malaysia / Q000453:epidemiology; D012107:Research Design; D012306:Risk; D013274:Stomach Neoplasms / Q000139:chemically induced / Q000453:epidemiology* / Q000382:microbiology / Q000517:prevention & control
D016588:Anticarcinogenic Agents; D002211:Capsaicin