Critique 007 9 June 2010
Alcohol, Changes with ageing
Molander RC, Yonker JA, Krahn DD. Age-related changes in drinking patterns from mid- to older age: results from the Wisconsin Longitudinal Study. Alcoholism: Clinical and Experimental Research 2010;34 (Published early online 7 May 2010).
Drinking has generally been shown to decline with age in older adults. However, results vary depending on the measure of alcohol consumption used and the study population. The goals of this study were to (i) describe changes in drinking in a current cohort of older adults using a variety of measures of drinking and (ii) examine a number of different possible predictors of change.
This is a longitudinal study of a community-based sample surveyed at 2 time points, ages 53 and 64 years. The authors estimated a series of logistic regressions to predict change and stability in drinking categories of nondrinking, moderate drinking, and heavy drinking. Linear regressions were used to predict change in past-month drinking days, past-month average drinks per drinking day, and past-month total drinks.
Results showed that from age 53 to 64, average drinks per drinking day and heavy drinking decreased. Frequency of drinking increased for men and women, and total drinks per month increased for men. The most consistent predictors of drinking changes were gender, health, and education. Other factors predicted drinking change but were not consistent across drinking measures including: adolescent IQ, income, lifetime history of alcohol-related problems, religious service attendance, depression, debt, and changes in employment.
The authors conclude that heavy drinking decreases with age, but we may see more frequent moderate drinking with current and upcoming cohorts of older adults. Components of quantity and frequency of drinking change differently. Composite measures of total alcohol consumption may not be adequate for describing relevant changes in drinking over time. A number of factors predicted patterns of change in drinking and warrant further exploration.
In a prospective longitudinal study in Wisconsin, USA of a current cohort of Americans in the “Baby Boomer” generation, subject’s drinking habits were assessed at two points, when they were approximately 53 years of age and again when they were approximately 64 years of age. This was a large study of high school graduates recruited in 1957; follow-up data were available in 2004 from more than 5,000 subjects.
The study showed that as the subjects got older, they began to consume fewer drinks per occasion but to consume alcohol more frequently; the net effect was little change in total alcohol intake for women but a slight increase for men. Given that regular moderate drinking is the pattern associated in observational epidemiologic studies with decreases in the risk of many chronic diseases, the described change in drinking pattern can be considered a “healthy” change, especially since many studies have shown greater survival for elderly subjects who consume alcohol moderately.1-3
Changes in pattern of drinking in the present study
The authors report that the number of drinking days increased for both women (4.57 to 5.51 days/month) and men (7.98 to 9.13 days/month). Among those who consumed alcohol on both occasions, average drinks per drinking day decreased from 1.80 to 1.55 for women and 2.31 to 2.11 for men. Factors associated with an increase in total drinks/month included being male, having greater education, and transitioning to unemployment. A decrease in the total number of drinks per month was predicted by experiencing a major medical diagnosis and hospitalization in the year prior to follow up.
Among subjects who were non-drinkers or moderate drinkers at baseline, 6% transitioned to heavy drinking by follow up; those with a history of alcohol-related problems at baseline were more likely to become heavy drinkers. For those who reported heavy drinking at baseline, more than one half (both men and women) reported no drinking or moderate drinking at the follow-up examination. As for remaining in the moderate drinking category throughout follow up, the authors state that “higher education, IQ, and income independently support continuous moderate drinking,” adding that “this may be due in part to greater disposable income, social activity and leisure time, and access to health information suggesting that moderate drinking may have health benefits.”
A key message from this paper is how important it is to know the pattern of drinking, and not just the total number of drinks consumed over a week, when evaluating the impact of alcohol consumption on health and disease.
Potential reasons for a decline in alcohol consumption with ageing
Most previous studies have shown that as people age, they begin to consume less alcohol;4 reasons for this decline are probably multiple. Vestal et al5 studied the effect of ageing on the distribution and elimination of ethanol in a group of 50 healthy men ranging in age from 21 to 81 years. Ethanol was administered in a continuous 1-hr infusion at a mean dose of 0.57 gm/kg body weight. At the end of the infusion period peak ethanol concentration in blood water was correlated with age and increased 33% over the adult life span (20 to 90 years of age). The mean peak ethanol concentration in the 25 older men (177 mg/dl) was around 15% higher than the peak ethanol in the 25 younger men (153 mg/dl). However, rates of ethanol elimination were not affected by age. The reasons why people drink (whether young, middle-aged, or elderly) are very complex, and poorly understood.
Another potential reason for the decline in alcohol intake with age found in most studies may be the development of chronic illness and poorer general health. Further, older people engage the health care system more frequently and are exposed to health care providers who, with good intent, often counsel patients toward lower consumption or abstinence. We find that, in clinical practice, as patients age and have more fragile health, there is introspection as to the consequences of long-term alcohol drinking on their well being, and this too influences patients’ choices. In our clinical experience, few people begin to drink as they become elderly, but most moderate drinkers continue to drink; however, binge drinking appears to occur less frequently.
It would be interesting to see data on the type of alcohol consumed over time among the subjects in this study. In a study from Framingham,4 ageing was associated with a lower percentage of total alcohol intake from beer and a higher percentage from wine. Indeed, the authors of this study state that “higher education, IQ, and income independently support continuous moderate drinking.” In most studies, these are generally found to be characteristics especially of wine drinkers.
Other factors associated with alcohol consumption in the elderly
This study reports that baseline depressive symptoms did not significantly predict changes in frequency, quantity, or heavy drinking, but did predict transitioning to nondrinking. While the subjects of this paper had not reached an age where supportive care or institutional care are often needed, such a transition might lead to a reduced accessibility to alcoholic beverages. It would be interesting to determine how adjustment for geriatric autonomy factors might affect the results; in terms of alcohol intake, to what extent do we maximize individual functional independence and personal goals when caring for the elderly?6 As asked by Lee,7 “How can physicians justify limiting a patient’s independence in the interest of his or her ‘own safety,’ when independence and the ability to continue living at home are essential for most older patients’ quality of life?”
References from Critique
1. Grønbæk M, et al. Alcohol and mortality: is there a U-shaped relation in elderly people? Age Ageing 1998;27:739-744.
2. Simons LA, et al. Alcohol intake and survival in the elderly: a 77-month follow-up in the Dubbo study. Aust NZ J Med 1996;26:662-670.
3. Thun MJ, et al. Alcohol consumption and mortality among middle-aged and elderly U.S. adults. N Engl J Med 1997;337:1705-1714.
4. Zhang Y, Guo X, Saitz R, Levy D, Sartini E, Niu J, Ellison RC. Secular trends in alcohol consumption over 50 years: the Framingham Study. Am J Med 2008;121:695-701.
5. Vestal RE, et al. Aging and ethanol metabolism. Clin Pharmacol Ther 1977;21:343-354.
6. Powers JS, et al. An autonomy supportive model of geriatric team function. Tenn Med 2000; 93:295-297.
7. Lee J. Autonomy and quality of life for elderly patients. Virtual Mentor 2008;10: 357-359.
In a large, prospective longitudinal study of a cohort of Americans in the “Baby Boomer” generation, subjects’ drinking habits were assessed at two points, when they were approximately 53 years of age and again when they were approximately 64 years of age. As the subjects got older, they began to consume fewer drinks per occasion but to consume alcohol more frequently; the net effect was little change in total alcohol intake for women but a slight increase for men. Given that regular moderate drinking is the pattern associated in observational epidemiologic studies with decreases in the risk of many chronic diseases, the described change in drinking pattern (smaller amounts on more frequent occasions) can be considered a “healthy” change. Most long-term observational studies show a decrease in total alcohol intake with ageing, although reasons for such are poorly understood.
This paper emphasizes the importance of knowing the pattern of drinking, and not just the total number of drinks consumed over a week, when evaluating the impact of alcohol consumption on health and disease.
* * *
Contributions to this critique by the International Scientific Forum on Alcohol Research were from the following:
Roger Corder, PhD, MRPharmS, William Harvey Research Institute, Queen Mary University of London, UK
R. Curtis Ellison, MD, Section of Preventive Medicine & Epidemiology, Boston University School of Medicine, Boston, MA, USA
Harvey Finkel, MD, Hematology/Oncology, Boston University Medical Center, Boston, MA, USA
Tedd Goldfinger, DO, FACC, Desert Cardiology of Tucson Heart Center, Dept. of Cardiology, University of Arizona School of Medicine, Tucson, Arizona, USA
Lynn Gretkowski, MD, Obstetrics/Gynecology, Mountainview, CA, Stanford University, Stanford, CA, USA
Professor Ross McCormick PhD, MSC, MBChB, Associate Dean, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
Erik Skovenborg, MD, Scandinavian Medical Alcohol Board, Practitioner, Aarhus, Denmark