Using the Nurses' Health Study, Qi Sun and colleagues examine whether moderate alcohol intake is associated with overall health and well-being among women who survive to older age.
Observational studies have documented inverse associations between moderate alcohol consumption and risk of premature death. It is largely unknown whether moderate alcohol intake is also associated with overall health and well-being among populations who have survived to older age. In this study, we prospectively examined alcohol use assessed at midlife in relation to successful ageing in a cohort of US women.
Methods and Findings
Alcohol consumption at midlife was assessed using a validated food frequency questionnaire. Subsequently, successful ageing was defined in 13,894 Nurses' Health Study participants who survived to age 70 or older, and whose health status was continuously updated. “Successful ageing” was considered as being free of 11 major chronic diseases and having no major cognitive impairment, physical impairment, or mental health limitations. Analyses were restricted to the 98.1% of participants who were not heavier drinkers (>45 g/d) at midlife. Of all eligible study participants, 1,491 (10.7%) achieved successful ageing. After multivariable adjustment of potential confounders, light-to-moderate alcohol consumption at midlife was associated with modestly increased odds of successful ageing. The odds ratios (95% confidence interval) were 1.0 (referent) for nondrinkers, 1.11 (0.96–1.29) for ≤5.0 g/d, 1.19 (1.01–1.40) for 5.1–15.0 g/d, 1.28 (1.03–1.58) for 15.1–30.0 g/d, and 1.24 (0.87–1.76) for 30.1–45.0 g/d. Meanwhile, independent of total alcohol intake, participants who drank alcohol at regular patterns throughout the week, rather than on a single occasion, had somewhat better odds of successful ageing; for example, the odds ratios (95% confidence interval) were 1.29 (1.01–1.64) and 1.47 (1.14–1.90) for those drinking 3–4 days and 5–7 days per week in comparison with nondrinkers, respectively, whereas the odds ratio was 1.10 (0.94–1.30) for those drinking only 1–2 days per week.
These data suggest that regular, moderate consumption of alcohol at midlife may be related to a modest increase in overall health status among women who survive to older ages.
Please see later in the article for the Editors' Summary
People have always drunk alcoholic beverages but throughout history there have been arguments about the risks and benefits of beer, wine, and spirits. It is clear that excessive alcohol use—heavy drinking (an average of more than two drinks per day for men or more than one drink per day for women; in the US, a “drink” is defined as 15 g of alcohol or, roughly speaking, a can of beer or a small glass of wine) or binge drinking (five or more drinks on a single occasion for men; 4 or more drinks at one time for women)—is harmful. It causes liver damage and increases the risk of developing some types of cancer. It contributes to depression and violence and interferes with relationships. And it is often implicated in fatal traffic accidents. However, in contrast to these and other harms associated with excessive alcohol use, moderate alcohol consumption seems to reduce the risk of specific diseases such as heart disease, stroke, and cognitive decline (deterioration in learning, reasoning, and perception).
Why Was This Study Done?
Although people who drink moderate amounts of alcohol have a reduced risk of premature death compared to abstainers or heavy drinkers, it is not known whether moderate alcohol consumption is associated with overall health among ageing populations. In many countries, elderly people are an increasingly large part of the population, so it is important to know how moderate alcohol consumption affects their well-being. In this study, the researchers examine the effect of alcohol consumption at midlife on successful ageing among the participants of the Nurses' Health Study. The researchers study the effect of midlife alcohol consumption because the chronic conditions that affect elderly people develop slowly and it is likely that factors in earlier life determine health in later life. Successful ageing is defined as being free of major chronic diseases such as cancer and heart disease, and having no major cognitive impairment, physical impairment, or mental health problems. The Nurses' Health Study enrolled 121,700 female registered nurses in 1976 to investigate the long-term effects of oral contraceptive use but has provided insights into many aspects of health and disease.
What Did the Researchers Do and Find?
The researchers assessed the alcohol consumption of the study participants at midlife (average age 58 years) from food frequency questionnaires completed in 1980 and 1984. Successful ageing for 13,984 participants who survived past 70 years was assessed by analyzing biennial health status questionnaires and cognitive function test results. One tenth of the women achieved successful ageing. After allowing for other factors that might affect their health such as smoking, women who drank light or moderate amounts of alcohol had a modestly increased chance of successful ageing compared to nondrinkers. For example, compared to nondrinkers, women who drank 5–15 g of alcohol per day (between one-third and one drink per day) had about a 20% higher chance of successful ageing. Independent of total alcohol intake, women who drank alcohol regularly had a better chance of successful ageing than occasional drinkers. Thus, compared to nondrinkers, women who drank five to seven days a week had nearly a 50% greater chance of successful ageing whereas women who drank only one or two days a week had a similar likelihood of successful ageing.
What Do These Findings Mean?
These findings suggest that regular, moderate consumption of alcohol at midlife may be related to a modest increase in overall health among women who survive to older ages. Because this is an observational study, it is possible that the women who drank moderately share other unknown characteristics that are actually responsible for their increased chance of successful ageing. Moreover, because all the study participants were women and most had European ancestry, these findings cannot be applied to men or to other ethnic groups. Nevertheless, these findings provide support for the 2010 US Department of Agriculture dietary guidelines, which state that consumption of up to one alcoholic drink per day for women and up to two alcoholic drinks per day for men may provide health benefits. Importantly, they also suggest that drinking alcohol regularly in moderation rather than occasional heavy drinking may be associated with a greater likelihood of successful ageing.
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001090.
The US National Institute on Alcohol Abuse and Alcoholism has detailed information about alcohol and its effects on health, including a fact sheet on women and alcohol and a booklet entitled Alcohol, a woman's health issue
The US Centers for Disease Control and Prevention has a website on alcohol and public health
The UK National Health Service Choices website provides detailed information about drinking and alcohol, including how to calculate consumption
The Nutrition Source, a website maintained by the Department of Nutrition at Harvard School of Public Health, has an article entitled Alcohol: balancing risks and benefits
MedlinePlus provides links to many other resources on alcohol and on seniors' health
Details of the Nurses' Health Study are available
The 2010 US Department of Agriculture dietary guidelines are available