Alcohol – a scoping review for Nordic Nutrition

A scoping review written by Dag Thelle and Morten Grønbæk evaluates the updated evidence on the consumption of alcohol and health outcomes regarded as relevant for the Nordic and Baltic countries, including cardiovascular disease, cancer, and all-cause mortality. The aim of the review is to describe the current evidence for selected health-related outcomes. This is asa basis for setting and updating national dietary reference values (DRVs) and food-based dietary guidelines (FBDGs) on alcohol consumption in the Nordic Nutrition Recommendations. The paper is one of many scoping reviews commissioned as part of the Nordic Nutrition Recommendations 2023 (NNR2023) project. It is based on the previous Nordic Nutrition Recommendations of 2012 and relevant papers published until 31 May 2021.
The review finds that alcohol consumption is associated with both negative and positive health effects. Current evidence from mainly conventional epidemiological studies suggests that regular, moderate alcohol consumption confers a modest protective effect against MI and possibly type 2 diabetes among middle-aged and older individuals. Conversely, alcohol consumption among young adults is detrimental, especially because of the tendency to binge drinking in this age group. For several cancers, there is convincing evidence that alcohol consumption increases the risk, and it is not possible to set any ‘safe limit’ of intake. This is especially true for breast cancer, where even moderate intake has been shown to increase the risk. Light to moderate regular alcohol consumption is not associated with increased mortality risk among middle-aged and older adults.
The review authors state that observational studies on alcohol consumption are hampered by a number of inherent methodological issues such as ascertainment of alcohol intake, selection of appropriate exposure groups, and insufficient control of confounding variables, colliders, and mediators. They add that it should also be emphasized that there is a socio-economic contribution to the alcohol-health axis with a stronger detrimental effect of alcohol in the lower social classes. The above issues contribute to the complexity of unravelling the causal web between alcohol, mediators, confounders, and health outcome.
Mendelian Randomization (MR) analyses, where genetic variants that are strongly associated with the potential risk factor are used as instrumental variables to determine whether the risk factor is a cause of the disease, do not fully support the findings above. This ispossibly because these analyses may fail to identify low alcohol intake. Currently, MR studies on the effect of alcohol on health are hampered by the lack of specific polymorphisms specifically addressing alcohol use.
Based on the overall evidence, the review recommends limiting alcohol intake. Based on estimates of the maximal mortality risk reduction associated with moderate alcohol consumption, the intake should not exceed 20 g (approximately two units) per day for both women and men. The consumption of alcohol should not exceed 5% of the energy intake in adults. Pregnant women, children, and adolescents are recommended to abstain from alcohol. Lactating women are recommended to follow the above.
Source: Thelle DS, Grønbæk (2024) M. Alcohol – a scoping review for Nordic Nutrition Recommendations 2023. Food and Nutrition Research, 68.