Daily Drinking Is Associated with Increased Mortality

Abstract

Background: There is evidence that low-level alcohol use, drinking 1 to 2 drinks on occasion, is protective for cardiovascular disease, but increases the risk of cancer. Synthesizing the overall impact of low-level alcohol use on health is therefore complex. The objective of this paper was to examine the association between frequency of low-level drinking and mortality.

Methods: Two data sets with self-reported alcohol use and mortality follow-up were analyzed: 340,668 individuals from the National Health Interview Survey (NHIS) and 93,653 individuals from the Veterans Health Administration (VA) outpatient medical records. Survival analyses were conducted to evaluate the association between low-level drinking frequency and mortality.

Results: The minimum risk drinking frequency among those who drink 1 to 2 drinks per occasion was found to be 3.2 times weekly in the NHIS data, based on a continuous measure of drinking frequency, and 2 to 3 times weekly in the VA data. Relative to these individuals with minimum risk, individuals who drink 7 times weekly had an adjusted hazard ratio (HR) of all-cause mortality of 1.23 (p < 0.0001) in the NHIS data, and individuals who drink 4 to 7 times weekly in the VA data also had an adjusted HR of 1.23 (p = 0.01). Secondary analyses in the NHIS data showed that the minimum risk was drinking 4 times weekly for cardiovascular mortality, and drinking monthly or less for cancer mortality. The associations were consistent in stratified analyses of men, women, and never smokers.

Conclusions: The minimum risk of low-level drinking frequency for all-cause mortality appears to be approximately 3 occasions weekly. The robustness of this finding is highlighted in 2 distinctly different data sets: a large epidemiological data set and a data set of veterans sampled from an outpatient clinic. Daily drinking, even at low levels, is detrimental to one's health.

Keywords: Alcohol Use; Cancer Mortality; Cardiovascular Mortality; Mortality.

Figure 1:

Patterns of alcohol use for each sample.

Figure 2:

Adjusted hazard ratios* of all-cause mortality by drinking frequency for individuals who drink 1–2 drinks on occasion and never binge drink. 2A. NHIS data, N=340,668; N deaths=30,498 *NHIS hazard ratios are adjusted for birth cohort, gender, race, typical drinking quantity when not binge drinking, frequency of binge drinking, health and wellness factors (current smoking status, perceived health status, exercise level, and medical comorbidities), socioeconomic factors (educational attainment, employment status, and whether the household received food stamps in the last calendar year), region of country, and year of survey. 2B. VA data, N=93,653; N deaths=8,322 *VA hazard ratios are adjusted for birth cohort, gender, race, typical drinking quantity when not binge drinking, frequency of binge drinking, and medical comorbidities.

Figure 3:

Estimated hazard ratios for mortality due to cardiovascular disease and cancer based on the frequency of non-binge drinking. Curves correspond to risk for individuals who typically drink 1–2 drinks per occasion and never binge in the NHIS dataset. *Hazard ratios are adjusted for birth cohort, gender, race, typical drinking quantity when not binge drinking, frequency of binge drinking, health and wellness factors (current smoking status, perceived health status, exercise level, and medical comorbidities), socioeconomic factors (educational attainment, employment status, and whether the household received food stamps in the last calendar year), region of country, and year of survey.

Figure 4:

Gender-stratified hazard ratios for mortality based on frequency of non-binge drinking. Curves correspond to risk for individuals who typically drink 1–2 drinks per occasion and never binge in the NHIS dataset. *Hazard ratios are adjusted for birth cohort, gender, race, typical drinking quantity when not binge drinking, frequency of binge drinking, health and wellness factors (current smoking status, perceived health status, exercise level, and medical comorbidities), socioeconomic factors (educational attainment, employment status, and whether the household received food stamps in the last calendar year), region of country, and year of survey.