BACKGROUND: Research has long found 'J-shaped' relationships between alcohol consumption and certain health outcomes, indicating a protective effect of moderate consumption. However, methodological limitations in most studies hinder causal inference. This review aimed to identify all observational studies employing improved approaches to mitigate confounding in characterizing alcohol-long-term health relationships, and to qualitatively synthesize their findings.
METHODS: Eligible studies met the above description, were longitudinal (with pre-defined exceptions), discretized alcohol consumption, and were conducted with human populations. MEDLINE, PsycINFO, Embase and SCOPUS were searched in May 2020, yielding 16 published manuscripts reporting on cancer, diabetes, dementia, mental health, cardiovascular health, mortality, HIV seroconversion, and musculoskeletal health. Risk of bias of cohort studies was evaluated using the Newcastle-Ottawa Scale, and a recently developed tool was used for Mendelian Randomization studies.
RESULTS: A variety of functional forms were found, including reverse J/J-shaped relationships for prostate cancer and related mortality, dementia risk, mental health, and certain lipids. However, most outcomes were only evaluated by a single study, and few studies provided information on the role of alcohol consumption pattern. CONCLUSIONS: More research employing enhanced causal inference methods is urgently required to accurately characterize alcohol-long-term health relationships. Those studies that have been conducted find a variety of linear and non-linear functional forms, with results tending to be discrepant even within specific health outcomes.
TRIAL REGISTRATION: PROSPERO registration number CRD42020185861.
BACKGROUND AND AIMS: Most studies assess the relationship between alcohol and stroke at some point. Little is known about the effect on stroke of drinking status changes over time. This study aimed to examine the association of median 2.4-year drinking status changes with risk of stroke.
METHODS AND RESULTS: We examined 22,691 adults from rural China. Drinking status was assessed at 2004-2006 and in 2008. Participants were divided into four change patterns: consistent non-drinkers, abstainers, starters, and consistent drinkers. A Cox proportional hazards model were performed. We observed 1215 cases of stroke during a median follow-up period of 11.8 years. A faint J-shaped association between alcohol consumption and risk of stroke was found in this population. Based on the amount of alcohol consumption, only current drinkers with >/=721 g/week at baseline in both males and females had a higher risk of stroke [hazard ratio (HR): 1.342; 95% confidence interval (CI): 1.070-1.683 and HR: 2.130; CI: 1.041-4.357, respectively]. Based on change patterns, Compared with consistent non-drinkers, the HR (95% CI) for consistent drinkers, abstainers and starters was 1.298 (1.070-1.576), 1.093 (0.877-1.362) and 1.263 (1.034-1.543), respectively. The same trend was observed in male. The HR (95% CI) for consistent drinkers, abstainers and starters was 1.360 (1.098-1.685), 1.139 (0.883-1.470) and 1.364 (1.092-1.703), respectively. No difference was observed in females.
CONCLUSION: High alcohol consumption was associated with increased risk of stroke in both males and females. However, based on change patterns, consistent drinkers and starters were at higher risk of stroke only in males.
Cardiovascular disease (CVD) morbidity and mortality is increasing, representing an important public health issue worldwide. It is well-known that risk of CVD is substantially influenced by lifestyle, including poor diet, tobacco smoking and physical inactivity.
In the last years, the so-called Mediterranean Diet (MedDiet) has been associated with broad healthy benefits on human health, including protection against CVD. The present narrative review aimed to summarize and discuss the evidence from meta-analyses of epidemiological and clinical trials analyzing MedDiet and CVD risk.
The MedDiet is one of the best dietary patterns analyzed in relation to CVD risk and other health outcomes. Studies demonstrated that MedDiet has beneficial effects in the prevention of total and specific types of CVD, albeit a moderate-high degree of inconsistency has been reported and few studies have been included in most of the meta-analyses. As consequence, more high-quality prospective cohorts and randomized clinical trials are warranted in order to increase the confidence in the effect estimates.