This latest study from PLOS Medicine found that among women, moderate drinking in midlife and living to age 70 without serious or chronic illness are correlated. This is the latest addition to an already robust evidence base for health benefits of moderate drinking, especially in midlife and older individuals. Strengths of this particular study were the prospective design, large sample size and the ability to statistically adjust findings to minimize bias from other factors such as diet and exercise. A few caveats are in order, however. First, correlation is not causation. In spite of statistical adjustments, it is simply not possible to completely eliminate the possibility that other, possibly unmeasured factors account for the correlation. Similarly, correlation is association and does not imply directionality. That is, do women who drink live longer and in better health, or do women who live longer and in better health drink more? Second, don't be too mesmerized by the "one standard drink a day" idea. That number is not what or how people actually drank. Instead, it is a number based on some question(s) about drinking, which are then usually grouped into categories for statistical analysis. For example, abstainers, less than monthly or weekly drinkers, weekly, daily drinkers. Or they may ask "On average, how many drinks do have in a day (or in week)?" and then average that number. The fact is, almost nobody in the US actually drinks one standard drink a day. Drinking varies a lot from day to day and week to week. I think of moderate drinking as regular non heavy drinking. For example, weekly or more often, and for women, never more than 3 standard drinks in any day or 7 drinks in any week (the NIAAA low risk drinking guideline.) For men, the numbers are no more than 4 standard drinks in any day and no more than 14 standard drinks in any week.
Oh, and by the way the type of alcoholic beverage is not important. Wine, beer and spirits all have pretty much the same effect.
OK, so caveats aside, what does this mean? My interpretation is that the evidence overwhelmingly supports a real health benefit associated with moderate drinking. That is, it is very unlikely that these findings are simply due to other factors. Moderate drinking is associated with reduced all cause and especially cardiovascular mortality, lower risk of developing diabetes, Alzheimer's Disease and rheumatoid arthritis. The likely mechanisms for this effect are several. First, drinking raises HDL (good) cholesterol levels. Second, it reduces inflammation, a key factor in development of many disorders. Finally, it increases insulin sensitivity. A decrease of insulin sensitivity is associated with developing Type II diabetes, the most common type.
Everyone is always worried about saying this, for fear that the streets will be flooded with middle aged alcoholics who started drinking to improve their health. Or, that currently addicted people will use this type of finding as an "excuse" to keep drinking. Hogwash! The risk that someone who starts moderate drinking in middle age will become addicted is trivial. In fact if they stay within the NIAAA guidelines, it's nonexistent. And my experience is that addicted people don't need an excuse to keep drinking. They don't drink for their health.
So if anyone is so inclined to start drinking or drink more regularly because of these findings, keep track of your drinking. If it goes above the low risk guidelines, cut back. Also, of course, the guidelines are for healthy adults. People with various health conditions such as liver disease may need to either abstain or drink at even lower levels. People older than 65 or 70, or those taking medications that might interact with alcohol should either abstain or modify their limits. I know I'm supposed to also suggest talking to your doctor about it first, but I'm afraid most doctors know almost nothing about drinking and its effects, and you are likely to get widely divergent advice from different doctors. Also, asking a doctor about something like this is like asking a lawyer about risk. You'll always get the most "conservative" answer, meaning one that puts the expert at lowest risk of being vulnerable. So doctors will be inclined to say don't drink at all, or keep it to one standard drink per day, or something like that. My advice: use your own best judgement, and stay within the low risk guidelines. You are very unlikely to cause harm, and keep in mind that the health benefits are pretty substantial. So advice to a middle aged person to abstain is not conservative in that abstainers get sick more and die younger than moderate drinkers. Finally, women who are pregnant or at risk of becoming pregnant should abstain due to potential fetal effects.
Alcohol Consumption at Midlife and Successful Ageing in Women: A Prospective Cohort Analysis in the Nurses' Health Study
Qi Sun1,2*, Mary K. Townsend2, Olivia I. Okereke2,3, Eric B. Rimm1,2,3, Frank B. Hu1,2,3, Meir J. Stampfer1,2,3, Francine Grodstein2,3
1 Department of Nutrition, Harvard School of Public Health, Boston, Massachusetts, United States of America, 2 Channing Laboratory, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, United States of America, 3 Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts, United States of America
Sun Q, Townsend MK, Okereke OI, Rimm EB, Hu FB, et al. (2011) Alcohol Consumption at Midlife and Successful Ageing in Women: A Prospective Cohort
Analysis in the Nurses’ Health Study. PLoS Med 8(9): e1001090. doi:10.1371/journal.pmed.1001090
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.