Alcohol is a risk factor for cancer of the oral cavity, pharynx, oesophagus, colorectum, liver, larynx and female breast, whereas its impact on other cancers remains controversial. We investigated the effect of alcohol on 23 cancer types through a meta-analytic approach. We used dose–response meta-regression models and investigated potential sources of heterogeneity. A total of 572 studies, including 486 538 cancer cases, were identified. Relative risks (RRs) for heavy drinkers compared with nondrinkers and occasional drinkers were 5.13 for oral and pharyngeal cancer, 4.95 for oesophageal squamous cell carcinoma, 1.44 for colorectal, 2.65 for laryngeal and 1.61 for breast cancer; for those neoplasms there was a clear dose–risk relationship. Heavy drinkers also had a significantly higher risk of cancer of the stomach (RR 1.21), liver (2.07), gallbladder (2.64), pancreas (1.19) and lung (1.15). There was indication of a positive association between alcohol consumption and risk of melanoma and prostate cancer. Alcohol consumption and risk of Hodgkin’s and Non-Hodgkin’s lymphomas were inversely associated. Alcohol increases risk of cancer of oral cavity and pharynx, oesophagus, colorectum, liver, larynx and female breast. There is accumulating evidence that alcohol drinking is associated with some other cancers such as pancreas and prostate cancer and melanoma.

There is convincing evidence that alcohol consumption increases the risk of cancer of the colorectum, breast, larynx, liver, esophagus, oral cavity and pharynx. Most of the data derive from studies that focused on the effect of moderate/high alcohol intakes, while little is known about light alcohol drinking (up to 1 drink/day). We evaluated the association between light drinking and cancer of the colorectum, breast, larynx, liver, esophagus, oral cavity and pharynx, through a meta-analytic approach. We searched epidemiological studies using PubMed, ISI Web of Science and EMBASE, published before December 2010. We included 222 articles comprising ∼92 000 light drinkers and 60 000 non-drinkers with cancer. Light drinking was associated with the risk of oropharyngeal cancer [relative risk, RR = 1.17; 95% confidence interval (CI) 1.06–1.29], esophageal squamous cell carcinoma (SCC) (RR = 1.30; 95% CI 1.09–1.56) and female breast cancer (RR = 1.05; 95% CI 1.02–1.08). We estimated that ∼5000 deaths from oropharyngeal cancer, 24 000 from esophageal SCC and 5000 from breast cancer were attributable to light drinking in 2004 worldwide. No association was found for colorectum, liver and larynx tumors. Light drinking increases the risk of cancer of oral cavity and pharynx, esophagus and female breast.

The study of probiotics to prevent allergic conditions has yielded conflicting results in children. We undertook a meta-analysis of randomized controlled trials to investigate whether probiotic use during pregnancy and early life decreases the incidence of atopic dermatitis and immunoglobulin E (IgE)-associated atopic dermatitis in infants and young children. We performed a systematic literature search in Medline, Embase, and Cochrane Library, updated to October 2011. The intervention was diet supplementation with probiotics versus placebo. Primary outcomes were incidence of atopic dermatitis and IgE-associated atopic dermatitis. We calculated summary relative risks (RRs) and corresponding 95% confidence intervals (CIs), using both fixed- and random-effects models. We computed summary estimates across several strata, including study period, type of patient, dose, and duration of intervention, and we assessed the risk of bias within and across trials. We identified 18 publications based on 14 studies. Meta-analysis demonstrated that probiotic use decreased the incidence of atopic dermatitis (RR = 0.79 [95% CI = 0.71−0.88]). Studies were fairly homogeneous (I2 = 24.0%). The corresponding RR of IgE-associated atopic dermatitis was 0.80 (95% CI = 0.66−0.96). No appreciable difference emerged across strata, nor was there evidence of publication bias. This meta-analysis provided evidence in support of a moderate role of probiotics in the prevention of atopic dermatitis and IgE-associated atopic dermatitis in infants. The favorable effect was similar regardless of the time of probiotic use (pregnancy or early life) or the subject(s) receiving probiotics (mother, child, or both).