In the current study, we demonstrated both low-to-moderate and heavy alcohol consumption, regardless of the type of alcoholic beverage consumed, to result in significantly greater levels of HDL cholesterol, HDL3 cholesterol, and apolipo-protein A-I in both white and African-American males and females of the large ARIC study. Associations with other lipid measures contrasted between whites and African Americans, as well as between males and females. HDL2 cholesterol levels were significantly associated with low-moderate and heavy drinking in both white males and females, but not in African Americans. Significantly lower levels of LDL cholesterol, apolipoprotein B, and triglycerides were observed only in white females, whereas significantly higher triglyceride levels were observed only in African-Americans. The small number of African-American wine drinkers precluded any conclusions about the association between lipid measures and wine consumption for this racial group. Overall, our results confirm previous studies associating alcohol consumption, regardless of beverage type, with higher HDL cholesterol levels, with additional consistent associations detected for the major HDL cholesterol density subfraction, HDL3 cholesterol, and the major HDL cholesterol structural apolipoprotein, apolipoprotein A-I.
The effects of alcohol consumption on lipid profiles have been primarily investigated in men, or when women have been included, the data were generally not analyzed by sex. The few studies evaluating this relationship in separate populations of men and women have indicated that the association of alcohol consumption with higher levels of HDL cholesterol occurs at lower intakes of alcohol in women than in men (23
). Results from the current study corroborate these previous findings. When comparing never drinkers to low-to-moderate drinkers, as well as never drinkers to heavy drinkers, the percent raise in HDL cholesterol levels was similar in both white and African-American men and women. However, these findings were observed for consuming ≤105 grams of alcohol per week for women (low-moderate; >105 grams/week for heavy) and for consuming ≤210 grams of alcohol per week for men (low-moderate; >210 grams/week for heavy). Women have been shown to be more sensitive to the effects of alcohol than men, especially with respect to liver function (37
). Greater blood alcohol concentrations have also been observed in women compared with men after ingestion of the same amount of alcohol, with this difference attributed to decreased gastric metabolism of alcohol by women (42
). Thus, the question has been raised as to whether alcohol consumption also affects lipid metabolism differently in men and women, but biochemical studies of lipid and alcohol metabolism have not addressed this issue (37
). In the current study, we observed similar changes in lipid levels at lower intakes of alcohol in women compared to men, but a mechanistic interpretation of these findings is difficult because of the lack of detailed metabolic and biochemical measures on these same individuals.
To our knowledge, this is the first study to investigate the association between alcoholic beverage consumption and lipid measures in a large sample of African Americans. The major HDL cholesterol density subfraction, HDL2
cholesterol, while significantly associated with drinking in whites, was not associated with alcohol consumption in African Americans. In addition, significantly higher triglyceride levels were associated with heavy drinking in African Americans, but not in whites. Previous research in the ARIC study has demonstrated differences in whites and African Americans with regards to HDL and triglyceride levels (43
). Although the mechanism(s) for these differences is not fully understood, it may partially be due to differences in body composition, glucose and insulin metabolism, and genetic factors. In never drinkers, triglyceride levels were lower in African Americans compared with whites, and HDL2
cholesterol levels were greater in African Americans compared with whites. However, in drinkers of alcohol (most notably heavy drinkers), triglyceride and HDL2
cholesterol levels were less disparate between African Americans and whites (). These finding are intriguing in light of the fact that the mechanism(s) by which alcohol affects lipid measures remains largely unknown (13
). The differences observed in whites and African Americans with respect to the effects of alcohol intake on lipid measures (never drinkers have different levels; heavy drinkers have similar levels) could potentially be explained by genetic differences and thus warrant further study.
FIGURE 1 Mean triglyceride levels in male ARIC participants according to alcohol intake and race. Values are adjusted for age, center, smoking status, cigarette years of smoking, BMI, education, physical activity, glucose, keys score, and cholesterol medication (more ...)
Limitations to the current study include the limited sample sizes obtained when classifying the race-sex strata by type of alcoholic beverage consumed, particularly in African Americans. Another limitation is that alcohol consumption data was obtained based on self-report. The validity of self-reported data on alcohol consumption has been debated, but there is evidence that the questionnaire administered to the ARIC participants adequately captured their alcohol consumption (34
). With regards to self-reported alcohol data, another concern is that different patterns of alcohol consumption in the ARIC cohort, such as binge drinking, could not be assessed. We were unable to determine whether an individual's pattern of drinking included regular drinking (i.e., daily drinking) or binge drinking (i.e., predominantly weekend drinking), which may differentially affect lipid levels. However, a previous controlled trial determined that the favorable effects of alcohol on lipid measures were independent of drinking patterns (18
Overall, the current study determined that both low-moderate and heavy alcohol consumption, regardless of the type of alcoholic beverage consumed, results in significantly greater levels of HDL cholesterol, HDL3
cholesterol, and apolipoprotein A-I in both white and African-American males and females. Alcohol consumption has been shown to contribute to a favorable lipid profile, and studies have consistently reported a reduction in CHD risk with low-moderate consumption of alcohol that is generally attributed to the beneficial effects of alcohol on lipids (1
). Alcohol consumption has been shown to have potential harmful effects on health as well, including increased risk for hypertension and hemorrhagic stroke, diseases that are more common in African Americans (36
). Previous research in the ARIC study showed an inverse association between alcohol consumption and incidence of CHD in white men and women, but found a positive association between alcohol consumption and CHD in African-American men (34
). Our observations of an absence of a beneficial effect of alcohol consumption on HDL2
cholesterol and greater triglyceride levels in African Americans may be one factor of several contributing to the absence of protection against CHD in African Americans of the ARIC cohort. Therefore, the beneficial effects of alcohol on cholesterol measures must be weighed against the potential harmful effects on health, with considerations given to one's sex, cardiovascular disease risk, family history, racial/ethnic background and drinking behavior.