A study has found that “middle-aged women who indulge in a drink or two a day are boosting their chance of good health in their seventies”,_ The Daily Telegraph_ reported.
This study was in 13,894 nurses in the US. Their alcohol consumption in midlife (average age 58 years) was monitored and compared with their chances of being free from major chronic disease and mental impairment in later life. Light to moderate alcohol consumption (about 0.6 to 3.75 units per day) during midlife was associated with a small (2.1%) absolute increase in the chance of being free of these conditions at age 70 compared with drinking no alcohol. The study also found that those who spread their midlife drinking over the week experienced more benefit than those who concentrated their alcohol consumption on just one or two days.
Overall, this research is consistent with other research showing that low to moderate alcohol consumption may be associated with improvements in some areas of health. However, it is important to remember that the harmful effects of drinking heavily are well established. See our Live Well pages on alcohol for the UK recommendations on consumption and other advice.
This study was carried out by researchers from the Harvard School of Public Health and Harvard Medical School. Funding was provided by grants from the National Institutes of Health and Boston Obesity Nutrition Research Centre.
The study was published in the open-access peer-reviewed journal PLoS Medicine .
The news coverage of this story was generally accurate. The_ Daily Mirror_ report may have given readers the mistaken impression that the study looked at drinking in old age, when it actually looked at the effects of drinking in midlife on the likelihood of healthy survival in old age.
This study examined the effect of alcohol consumption during midlife on women’s chances of being free from major chronic disease and mental impairment in later life. The researchers focused on aspects of what they called “successful ageing”, which they defined as “being free of 11 major chronic diseases and having no major cognitive impairment, physical impairment or mental health limitations”.
The authors state that previous research has found that moderate alcohol consumption reduces the risk of premature death. However, it is largely unknown whether moderate alcohol intake is also associated with overall health and wellbeing among populations who have survived to older age.
This research looked at a subset of women taking part in a prospective cohort study in the US called the Nurses’ Health Study. A cohort study is an appropriate and feasible study design for assessing the relationship between alcohol consumption in midlife and successful ageing later on.
The Nurses’ Health Study was established in 1976 when it enrolled 121,700 female nurses. Every two years afterwards the women were sent questionnaires asking them about their lifestyle and medical history.
Consumption of beer, wine and liquor at midlife (average [median] age 58 years) was assessed using a validated food frequency questionnaire. The alcohol consumption results from the 1980 and 1984 questionnaires were then averaged to determine each woman’s daily midlife alcohol use. One drink was defined as a 355ml bottle or can of beer, a 118ml glass of wine or a shot of liquor.
These same women were followed up at age 70 or older and their health status checked to see if they had “successfully aged” as the researchers put it. Successful ageing was considered to be being free of 11 major chronic diseases (including cancer, diabetes and heart disease) and having no major cognitive impairment, physical impairment or mental health limitations.
In the Nurses’ Health Study, 21,202 were 70 years or older and free of stroke in 1995-2001. These women were invited to participate in the study. The researchers excluded women who drank more than 45g of alcohol a day (5.6 units) at midlife. They also excluded women who already had chronic diseases at the start of the study; had been diagnosed with alcohol dependence, chronic liver disease or cirrhosis; had missing information on health outcomes or alcohol use; or reported having substantially reduced their alcohol consumption when asked in 1980 (as this could indicate problems with alcohol). This left 13,894 female nurses for the current analysis.
The statistical analysis took into account a range of factors that could have potentially influenced the relationship between midlife alcohol consumption and successful ageing (confounders). These were: age; body mass index; physical activity; smoking status; level of education; husband’s level of education; marital status; postmenopausal hormone use; family history of heart disease, diabetes or cancer; personal history of hypertension or high cholesterol; use of aspirin and dietary intake of fruit and vegetables, wholegrains, fish and red meat.
Of the eligible participants, 10.7% achieved “successful ageing”. A quarter of women did not drink in midlife, while 62.1% drank about one drink a day, 9.8% drank about one to two drinks a day and 9.8% drank two to three drinks a day. The vast majority of women who drank in midlife drank wine.
The researchers found that, after taking into account the influence of a range of potential confounders:
After taking into account total alcohol consumption, these differences were more pronounced in people who drank alcohol more regularly throughout the week, rather than on fewer occasions. This was demonstrated by the finding that people who drank on one to two days a week had the same chances of successfully ageing as non-drinkers. Those drinking on three to four days in midlife were 29% more likely to have successful ageing than non-drinkers (OR 1.29, 95% CI 1.01 to 1.64). Those who drank on five to seven days per week in midlife were 47% more likely to have successful ageing than non-drinkers (OR 1.47, 95% CI 1.14 to 1.90).
The researchers state that “these results 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 age”. In addition, they say their results “suggest the potential importance of drinking pattern in the relationship between alcohol use and successful ageing”.
The results of this analysis of a large prospective cohort study of female nurses suggest that light to moderate alcohol consumption during midlife is associated with a modestly improved overall chance of being free of major chronic disease and mental impairment at 70 years of age. In addition, they suggest that those who spread their drinking out over more days of the week may be more likely to achieve successful ageing than those concentrating consumption over just a few days.
While this study has some strengths, such as its size and prospective data collection, the following issues need to be considered when interpreting the results:
Overall, this research provides evidence that light to moderate alcohol consumption, in the region of one to two drinks per day, is associated with an increased chance of ageing successfully in women of European origin. This is consistent with other research showing that light to moderate drinking may be associated with improvements in some areas of health. It is more difficult to be certain that the drinking itself is causing these improvements, and not other factors.
However, it is important to remember that the harmful effects of drinking heavily are well established. The current UK recommendations are that people who drink should drink no more than three to four units of alcohol per day for men (approximately one pint of high strength larger) and two to three units for women (approximately one standard size glass of wine).