Introduction: A Complex Relationship Between Wine and Cancer
In a recent study published within the journal Frontiers in Nutrition, researchers performed meta-analytical research to find out the connection between wine intake and cancer.
Cancer is considered one of the leading causes of morbidity and mortality worldwide. Smoking, alcohol use, tobacco intake, and a high body mass index (BMI) are the critical risk aspects determining the whole burden of cancer. Interestingly, while alcohol consumption has been linked to an increased risk of developing various cancers (including those of the top, neck, upper gastrointestinal tract, breast, liver, rectum, and colon), wine consumption in moderate quantities has demonstrated opposing effects. The present understanding of alcohol intake and cancer stays contentious, particularly concerning wine consumption, warranting further research.
In the current meta-analysis, researchers investigated whether wine consumption can increase cancer risk.
Study: Association between wine consumption and cancer: a scientific review and meta-analysis. Image Credit: DALL·E 3
Data Pool and Inclusion Criteria
The Cochrane, Scopus, Web of Science, and MEDLINE (PubMed) databases were searched from their inception through to December 12, 2022, for relevant records without publication date limitations. Moreover, the team screened references from previously conducted qualitative (systematic reviews) and quantitative (meta-analyses) research. Only longitudinal studies evaluating the link between wine intake and cancers of the upper gastrointestinal tract, kidneys, colon, rectum, skin, pancreas, brain, lungs, and gynecological tissues were included.
The team excluded reviews, editorials, ecological studies, case reports, studies not published in Spanish or English, and people with no separate wine intake documentation amongst different alcohol types. Two reviewers performed study selection, bias risk assessments, and data extraction, and discrepancies were solved by discussion or consulting a 3rd reviewer. Bias risks were evaluated using the Newcastle-Ottawa Scale (NOS).
The team used the DerSimonian and Laird methods to find out the pooled relative risks (RRs). The I2 and τ2 statistics were utilized to judge inconsistency and heterogeneity, respectively. A five-year follow-up was determined because the eligibility criteria for the included studies for quantitative research to make sure data quality.
The team performed a sensitivity assessment by eliminating studies one by one from the first evaluation. As well as, they performed continent-wise subgroup analyses. In addition they performed random effects-type meta-regressions to judge the impact of participants’ age, female proportion, and follow-up durations on the link between wine intake and cancer risk. Egger’s regression asymmetries were assessed to find out publication bias.
What the Data Reveals
The literature search yielded 12,651 studies; the title and abstract review excluded 8,380, and 377 were assessed for eligibility. Finally, 73 studies were included within the systematic review. In total, 31 studies were cohort studies, and 42 were case-control studies.
Study settings within the included records included america (US), Australia, Recent Zealand, Greece, Canada, Uruguay, Argentina, the Netherlands, Italy, Denmark, Hawaii, the UK (UK), Puerto Rico, France, Germany, Spain, Norway, and Sweden. The publication period of the included studies ranged from 1986 to 2021, and the studies included 4,346,504 individuals 18 to 103 years of age.
The NOS scores of the included studies ranged between seven and nine, indicating top quality. The pooled relative risks for the impact of wine intake on the chance of gynecological, colorectal, renal, breast, and ovarian tumors were 1.0, 0.9, 0.9, 1.0, and 1.0, respectively. The heterogeneity within the included studies was greater than 50% to 75%.
Publication bias was reported for ovarian and renal tumors. Sensitivity and subgroup analyses yielded similar findings, indicating that the first evaluation results were robust. Follow-up durations impacted pooled RRs for the link between wine intake and tumors of the kidneys, rectum, and colon. The inverse associations between wine intake and specific cancers may very well be resulting from wine components comparable to phytoestrogens and antioxidants.
The Biochemistry Behind Wine’s Effects
It has been established that alcohol is related to gastric cancer, however the association has been claimed to be lessened amongst individuals who drink wine as a substitute of other alcoholic beverages. Wine can raise stomach acidity, which can inhibit the event of microorganisms comparable to Helicobacter pylori. In earlier investigations, wine was shown to have neuroprotective advantages when ingested in small amounts.
Wine components, including resveratrol, exert anti-mutagenic, anti-inflammatory, and antioxidant effects in carcinogenesis, with anti-inflammatory effects lasting in the course of the acute in addition to chronic stages of inflammation. Moreover, by causing cyclooxygenase 1 (COX1) suppression, resveratrol can impede the cellular processes of tumor genesis, development, and progression. Other anticarcinogenic components include quercetin, tannins, and anthocyanins, which protect against UV radiation and inhibit free radicals and myeloperoxidase (MPO) and cyclooxygenase-2 (COX-2) enzymatic activity, reducing skin cancer growth.
Overall, the study findings showed no link between wine intake and cancer risk. Quite the opposite, wine consumption showed protective trends regarding the risk of tumor development, especially within the brain, lungs, skin, and pancreas. Nonetheless, wine intake was not uniformly defined across studies; the chosen studies had different methodologies and didn’t document wine consumption volumes. Further research documenting alcohol intake in similar units, considering potential confounders comparable to weight loss program, lifestyle, and socioeconomic status with low heterogeneity, is required to find out the true impact of wine consumption in diverse populations.