Poultry and Fish Consumption in Relation to Total Cancer Mortality: A Meta-Analysis of Prospective Studies

Abstract

Observational studies on the association between fish and poultry intake and the risk of total cancer mortality have been reported with mixed results. Thus, we aimed to assess this association by conducting a meta-analysis of prospective studies. We performed a literature search on PubMed database through February 1, 2017 to identify relative prospective studies. A random-effects model was used to calculate the summary estimates. We identified fourteen prospective studies involving 2,378,204 participants and 96,712 cancer mortality events. Comparing the highest category of consumption with lowest category, pooled relative risk (RR) of total cancer mortality was 0.99 (95% confidence interval [CI], 0.94-1.05) for fish (10 studies) and 0.96 (95% CI, 0.93-1.00) for poultry (8 studies), respectively. However, we failed to identify any dose-response association based on a limited number of eligible studies, with a pooled RR of 0.98 (95% CI, 0.92-1.05) and 0.97 (95% CI, 0.88-1.07) for each 100 g per day increment in fish and poultry consumption, respectively. In summary, this meta-analysis indicates that consumption of either fish or poultry is not substantially associated with lower risk of total cancer mortality. The observed weak inverse association for high poultry consumption needs to be verified in additional large prospective studies.

Blood n-3 fatty acid levels and total and cause-specific mortality from 17 prospective studies

“…Our findings of lower risk of CVD death with high vs. low blood levels of EPA + DHA are generally consistent with metaanalyses of self-reported fish intake 25 and of biomarker levels 4 , as well as randomized controlled clinical trials of n-3 PUFA supplementation 3,43 (although the most recent trial 44 has not yet been included in meta-analyses). Compared with CVD, evidence for a link between n-3 PUFAs and cancer mortality risk is sparse, with no significant relationship for self-reported estimates of fish or n-3 PUFA consumption 25,45 . Meta-analyses of RCTs with n-3 PUFA supplements also have not observed effects on cancer, although short-term durations of such trials (generally up to 5 years) would likely preclude any ability to detect an effect on cancer 46,47 .…”

Investigation of bias due to selective inclusion of study effect estimates in meta-analyses of nutrition research

“…Initially, all SRs with a continuous outcome were included, and 25 of the 74 SRs with a non-continuous outcome were randomly selected. However, from these 50 SRs, eight were excluded (6 continuous, 2 non-continuous), because the index meta-analysis had 20 or more studies, leaving 42 included SRs 22-41 42-46 47-51 52,53 [54][55][56][57][58][59][60][61][62][63] . After extracting data from the included studies of these 42 SRs, we excluded a further three SRs because we were unable to identify the relevant outcome data in any of the included primary study reports 61 , or none of the included studies had multiplicity of effect estimates 62 63 .…”

Fish consumption in multiple health outcomes: an umbrella review of meta-analyses of observational and clinical studies

“…After following the selection process, 91 meta-analyses and systematic reviews of RCTs and observational studies with 66 unique health outcomes were identified, with most outcomes having more than one meta-analysis. The association between fish consumption and mortality is presented in Table 1 (19)(20)(21)(22)(23)(24)(25)(26)(27). Table 2 (14,22,(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45) presents the associations between consumption of fish and cancer outcomes (46)(47)(48)(49)(50)(51)(52)(53)(54)(55)(56)(57)(58)(59)(60)(61)(62)…”