The authors state that they carried out analyses in a prospective cohort study of 11,914 Danes aged 20 years or older and without pre-existing ischaemic heart disease (IHD) to determine the combined influence of leisure-time physical activity and weekly alcohol intake on the risk of subsequent fatal IHD and all-cause mortality. During approximately 20 years of follow up, 1,242 cases of fatal IHD occurred and 5,901 subjects died from all causes.
Within both genders, being physically active was associated with lower hazard ratios (HR) of both fatal IHD and all-cause mortality than being physically inactive. Further, weekly alcohol intake was inversely associated with fatal IHD and had a U-shaped association with all-cause mortality. Within level of physical activity, non-drinkers had the highest HR of fatal IHD, whereas both non-drinkers and heavy drinkers had the highest HR of all-cause mortality. Further, the physically inactive had the highest HR of both fatal IHD and all-cause mortality within each category of weekly alcohol intake. Thus, the HR of both fatal IHD and all-cause mortality were low among the physically active who had a moderate alcohol intake. The authors conclude that leisure-time physical activity and a moderate weekly alcohol intake are both important to lower the risk of fatal IHD and all-cause mortality.
Comments by R. Curtis Ellison: Over the past decades, numerous studies have shown that light-to-moderate alcohol consumption decreases the risk of death from coronary disease, as well as all-cause mortality. A large number of studies have also demonstrated that physical activity is associated with a reduced risk of such outcomes. However, few studies have examined the synergistic effect of physical activity and alcohol consumption on all-cause mortality or mortality from ischaemic heart disease.
Results from this large-scale prospective epidemiologic study indicated that both physical activity and moderate alcohol consumption have independent beneficial effects on risk of fatal ischaemic heart disease. The low risk of fatal ischaemic heart disease is more apparent among subjects who drank alcohol moderately and also engaged in some level of physical activity. However, a beneficial effect of moderate alcohol consumption on all-cause mortality was observed mainly among physically active subjects.
Figures 1 and 2 from the paper are copied below. As shown in Figure 1, compared with inactive subjects (dark dots) consuming <1 drink/week, the risk of heart disease for those inactive subjects who drink 1-14 (center column) or 15+ drinks/week (right column) decreases by about 30%. At each level of alcohol intake, those who were active (open dots) showed reduced risk in comparison with inactive subjects.
For all-cause mortality, shown in Figure 2, no alcohol effect was seen for inactive persons. For those with low or moderate to high activity, however, there was a reduction in risk going from the <1 drink/week group to the moderate (1-14 drinks/week) group. The risk for those drinking 15+ drinks/week appears to increase.
The bottom line appears to be that alcohol reduces the risk of ischaemic heart disease regardless of activity. All drinkers show further reduction if they are also physically active; in this study, there was little difference according to the level of physical activity.
For all-cause mortality, the moderate drinkers (1-14 drinks/week) who are active do best. Those who drink 15+ drinks/week show higher mortality risk. Even among heavier drinkers, however, there is evidence of reduced all-cause mortality with physical activity.
Source: The combined influence of leisure-time physical activity and weekly alcohol intake on fatal ischaemic heart disease and all-cause mortality. Pedersen JO, Heitmann BL, Schnohr P, Grønbæk M. European Heart Journal 2008;29:204212.