Beer and Health: Making up the BalanceBeer and Health
Beer is made from natural ingredients and has relatively low (or zero) alcohol content compared to most other alcoholic beverages. Drinking beer in moderation can have a positive effect on life expectancy, due to the alcohol in it. There is a J-shaped relationship between alcohol consumption and all-cause mortality, with the lowest relative risk (with an approximate 10% decrease) associated with the consumption of around 20 g of alcohol per day for men and 10 g of alcohol per day for women. This effect is the sum of the positive effects on cardiovascular disease risk at moderate intake and the negative effects on certain cancers and accidents with higher consumption. It is unrelated to the type of alcoholic beverage.
- Beer is a versatile drink with a relatively low alcohol percentage, that when drank in moderation, can be part of an adult’s healthy lifestyle.
- Drinking beer in moderation may have positive effects on life expectancy, mainly due to the presence of alcohol.
- In addition to the effects associated with alcohol, other properties of beer arising from the raw materials and brewing processes, may also have positive effects on health.
- However, moderate alcohol consumption should always be considered as a supplement to, and not as an alternative to, other healthy lifestyle choices that lower the risk of coronary heart disease, type 2 diabetes and other diseases.
- People who do drink beer or other alcoholic beverages are encouraged to drink in moderation as part of a healthy diet.
- For people who don’t want to consume alcohol, non-alcoholic beer can be a good alternative.
Alcohol consumption and life expectancy
A population study in 1926 had already shown that moderate drinkers live longer than abstainers and heavy drinkers,283 and a J-shaped relationship between alcohol consumption and mortality risk has also been seen in numerous other studies performed more recently (see Table 7 and Figure 11). Overall, the lowest mortality relative risk with about a 10% decrease is observed with the consumption of around 20 g of alcohol per day for men and 10 g of alcohol per day for women. The relative risk increases again with a consumption of more than 40 g of alcohol per day for men and 20 g of alcohol per day for women. The net health benefit from moderate alcohol consumption is thought to act primarily through its cardio-protective effect (see Chapter 5), though increased alcohol consumption is also associated with an increased risk of certain cancers (see Chapter 7) and death from accidents.
|Table 7. Overview of studies focusing on the relationship between alcohol consumption and mortality risk|
|Ref no.||Study||#Subjects||Mortality risk reduction (alcohol dose)||Mortality risk increases|
|285||Meta-analysis, 34 studies||1,015,835||17% (6 g alcohol per day)||18% (5 g alcohol per day)||>40 g alcohol per day||>20 g alcohol per day|
|286||Meta-analysis, 24 studies||2,424,964||8% (25 g alcohol per day)||9% (25 g alcohol per day)||>75 g alcohol per day||>50 g alcohol per day|
|287||Meta-analysis, 9 studies||62,950||10% (1–29 g alcohol per day)||>40 g alcohol per day|
|288||Population study (European Prospective Investigation into Cancer and Nutrition)||380,395||10% (<=24 g alcohol per day)||7% (<=12 g alcohol per day)||>60 g alcohol per day||>30 g alcohol per day|
|289||Population study (Melbourne Collaborative Cohort Study)||39,577||19% (20–39 g alcohol per day)||15% (>0–9 g alcohol per day)||>=80 g alcohol per day||>=40 g alcohol per day|
Some scientists suggest that it is better to measure lifetime alcohol consumption and not only the consumption at study entry (baseline). The reason for this is that alcohol consumption is likely to vary over time. 290Therefore, the association between alcohol and mortality might be underestimated or overestimated when only baseline consumption is considered. However, studies that measured lifetime alcohol consumption also showed similar J-shaped relationships with all-cause mortality risk.288,289
Transient and reversible effect
The effect of alcohol on mortality risk may be transient and reversible based on data from a 5-year follow-up population study. Subjects with a stable pattern of light to moderate alcohol consumption (12–72 g alcohol per week) had the lowest all-cause mortality risk. Those individuals starting to drink less or those starting to drink more had a 29% and 32% higher relative risk during follow-up, respectively.291
Critical appraisal on alcohol research
The J-shaped relationship between alcohol consumption and all-cause mortality is a combined result from many studies. The challenge with these is that residual, unmeasured or confounding results can never be completely excluded. Few epidemiological observations, however, have been scrutinised for bias as thoroughly as the apparent health benefits of moderate alcohol consumption, 292but some uncertainty remains regarding the causal nature of the J-shaped association seen in population studies. Several methodological flaws have been shown in alcohol research that might produce apparent benefits of moderate drinking, as discussed below.
The ‘sick quitters’ hypothesis
Some studies failed to separate lifelong abstainers from ex-drinkers. The non-drinker reference group might therefore include ‘sick quitters’, being those who stop drinking alcoholic beverages because of health problems. 293This may lead to the impression of benefits from moderate drinking, though studies that separated ex-drinkers from lifelong abstainers have refuted this hypothesis.103
The ‘healthy drinker’ hypothesis
Another potential source of confounding evidence is the suggested healthier lifestyle of moderate drinkers, or conversely, non-drinkers may show an adverse risk profile. 294,295Some studies suggest that the J-shaped relationship between alcohol consumption, cardiovascular disease (CVD) and type 2 diabetes is not likely to be explained by a healthy lifestyle. However, even in those with a healthy lifestyle, moderate alcohol consumption is associated with an additionally lower risk of CVD and type 2 diabetes (see Chapters 5 and 6).
Assessment of actual alcohol consumption
Another concern is the accuracy of alcohol consumption assessments. To date, there is no widely accepted consensus on how to measure alcohol consumption. Data on alcohol consumption are often based on self-reporting, which can lead to the possibility of misclassification of exposure, and especially the under-reporting of alcohol consumption is a source of potential bias.296 Including heavier drinkers in lower intake categories will lower the threshold of apparent harm, as seen for example in a study showing that the prevalence of hypertension with people reporting to consume 1–2 drinks per day was essentially limited to suspected under-reporters.297
In conclusion: Beer and health
All the previous chapters in this booklet show us that beer is a versatile drink with relatively low alcohol percentage, that when drank in moderation, can be part of an adult’s healthy lifestyle. Due to the natural ingredients there are small amounts of B vitamins, minerals, polyphenols and fibre in beer. And because of the alcohol there may be positive effects on life expectancy. For people who don’t want to consume alcohol, non-alcoholic beer can be a good alternative.
Moderate alcohol consumption
There are many adverse effects of heavy alcohol consumption. On the other hand, moderate drinking may have beneficial effects on health, despite an increased relative risk of certain types of cancer. Mainly, there appears to be a lower risk of cardiovascular disease, type 2 diabetes and dementia that may explain the overall lower relative mortality risk (by around 10%) with the consumption of 10–20 g alcohol per day. This is unrelated to the type of alcoholic beverage. The most favourable drinking pattern is regular daily or almost daily drinking, and avoiding harmful binge drinking.298
Although residual confounding results cannot be excluded, it would be unlikely that they would modify the presented scenarios in any substantial way. 285The consistency and temporal sequence in epidemiological studies and the plausible biological explanations in experimental studies all favour the conclusion that moderate alcohol consumption does have beneficial health effects, 299and the benefits of moderate drinking is relevant for public health. 285However, moderate alcohol consumption should always be considered as a supplement to, and not as an alternative to, other healthy lifestyle habits that also lower the risk of chronic diseases, such as coronary heart disease and diabetes.
Remember: A healthy lifestyle is possible with or without drinking beer
Although moderate beer consumption may have health benefits, you do not have to drink beer in moderate amounts for a healthy lifestyle. To ensure a healthy lifestyle, the World Health Organization (WHO) recommends eating lots of fruit and vegetables, reducing fat, sugar and salt intake, and exercising. What is important, is that if you do drink beer, to do so responsibly and in moderation.
Remember: Alcohol affects women differently to men
Alcohol affects women differently to men mainly because of their different body composition and lower average body weight. Women have a higher percentage of fat in their body and therefore a lower percentage of body fluid. Since alcohol is water-soluble, it is distributed only in body fluid. Women will therefore have higher peak blood alcohol levels than men when they drink the same amount of alcohol (see Table 8). 81Other possible mechanisms to explain gender differences in blood alcohol concentration include differences in the relative metabolism of alcohol, the interaction of alcohol dehydrogenase (ADH) with female sex hormones, lower levels of gastric ADH, and more rapid metabolism in the liver by women.300
The difference in blood alcohol concentration between men and women may explain the reason why the inverse association for life expectancy in women disappears at lower alcohol intake compared to that in men, probably due to an increased relative risk of (breast) cancer.284
|Table 8. Example of peak blood alcohol concentration in men and women after drinking the same amount of alcohol|
|Body fluid (%)||65||55|
|Body fluid (kg)||52||35|
|Alcohol from one unit (g||10|
|Peak blood alcohol concentration (%)||0.02||0.03|