Alcohol, coffee and tea intake and the risk of cognitive deficits: a dose–response meta-analysis

Abstract

Aims Lifestyle interventions are an important and viable approach for preventing cognitive deficits. However, the results of studies on alcohol, coffee and tea consumption in relation to cognitive decline have been divergent, likely due to confounds from dose–response effects. This meta-analysis aimed to find the dose–response relationship between alcohol, coffee or tea consumption and cognitive deficits. Methods Prospective cohort studies or nested case-control studies in a cohort investigating the risk factors of cognitive deficits were searched in PubMed, Embase, the Cochrane and Web of Science up to 4th June 2020. Two authors searched the databases and extracted the data independently. We also assessed the quality of the studies with the Newcastle-Ottawa scale. Stata 15.0 software was used to perform model estimation and plot the linear or nonlinear dose–response relationship graphs. Results The search identified 29 prospective studies from America, Japan, China and some European countries. The dose–response relationships showed that compared to non-drinkers, low consumption (<11 g/day) of alcohol could reduce the risk of cognitive deficits or only dementias, but there was no significant effect of heavier drinking (>11 g/day). Low consumption of coffee reduced the risk of any cognitive deficit (<2.8 cups/day) or dementia (<2.3 cups/day). Green tea consumption was a significant protective factor for cognitive health (relative risk, 0.94; 95% confidence intervals, 0.92–0.97), with one cup of tea per day brings a 6% reduction in risk of cognitive deficits. Conclusions Light consumption of alcohol (<11 g/day) and coffee (<2.8 cups/day) was associated with reduced risk of cognitive deficits. Cognitive benefits of green tea consumption increased with the daily consumption.

Nutrition, Physical Activity, and Other Lifestyle Factors in the Prevention of Cognitive Decline and Dementia

“…Since the results of studies in humans on alcohol, coffee, and tea consumption in relation to cognitive decline have been incongruous, a recent meta-analysis of 29 prospective cohort studies or nested case-control studies in a cohort from different countries worldwide aimed to find the dose-response relationship between alcohol, coffee, or tea consumption and cognitive deficits. The dose-response relationships showed that compared to nondrinkers, green tea consumption was a significant protective factor for cognitive health; one cup of tea per day was associated with a 6% reduction in the risk of cognitive deficits [177].…”

“…Recent investigations continue to provide inconsistent results. A meta-analysis aiming to investigate the dose-response relationship between alcohol, coffee, or tea consumption and cognitive deficits including prospective cohort studies or nested case-control studies (n = 29) from America, Japan, China, and some European countries published up to June 2020 found that a low consumption of coffee reduced the risk of any cognitive deficit (<2.8 cups/day) or dementia (<2.3 cups/day) [177]. Conversely, a study exploring the effect of lifetime coffee consumption on the volume of white matter hyperintensities (VWMH) in late life examining 492 cognitively normal community-dwelling men and women (mean age 73.4 ± 6.7 years) from the Korean Longitudinal Study on Cognitive Aging and Dementia found that higher cumulative lifetime coffee consumption was associated with significantly higher log VWMH in both sexes.…”

Prevalence of Dementia in China in 2015: A Nationwide Community-Based Study

“…For tea-drinking, our result showed that both green tea and black tea were the protective factors for dementia and AD. A few studies have reported the hypothesis that green tea intake might reduce the risk for dementia, AD ( 26 ). However, whether black tea intake was associated with dementia and AD needs further research.…”

Green Tea Suppresses Brain Aging

“…In fact, green tea consumption has been epidemiologically shown to be inversely associated with both male and female heart disease mortality and male cerebrovascular and respiratory mortality [ 2 ]. In addition, there are accumulating reports that the ingestion of green tea is effective in preventing dementia [ 3 , 4 , 5 , 6 , 7 ]. In order to elucidate the effect of green tea, studies mainly focusing on the antioxidant effect of epigallocatechin gallate (EGCG) have been conducted in vivo and in vitro [ 8 , 9 , 10 , 11 ].…”