The Effect of Alcohol on Blood Pressure and Hypertension.

Purpose To examine the acute and chronic effects of alcohol on blood pressure (BP) and the incidence of hypertension. We discuss the most current understanding of the mechanisms underlining these effects and their associations with the putative cardioprotective effects of consumption of low-to-moderate amounts of alcoholic beverages. Recent findings A recent meta-analysis confirmed findings of experimental studies, demonstrating an acute biphasic effect of ethanol on BP, decreasing up to 12 h of ingestion and increasing after that. This effect is mediated by vagal inhibition and sympathetic activation. A meta-analysis found that chronic consumption of alcoholic beverages was associated with a high incidence of hypertension in men and women; it also found that, in women, the risk begins at moderate alcohol consumption. The risks of alcohol consumption are higher in Blacks than in Asians or Caucasians. The mechanism underlying the chronic effects of alcohol on BP, and particularly the differential effect on Blacks, is still unknown. Short-term trials showed that alcohol withdrawal promotes BP reduction; however, the long-term effectiveness of interventions that aim to lower BP through the restriction of alcohol consumption has not been demonstrated. The harmful effects of alcohol on BP do not support the putative cardioprotective effect of low-to-moderate consumption of alcoholic beverages. The absence of a tangible mechanism of protection, and the possibility that this beneficial effect is biased by socioeconomic and other characteristics of drinkers and abstainers, calls into question the hypothesis that consuming low amounts of alcoholic beverages improves cardiovascular health. The evidence from investigations with various designs converge regarding the acute biphasic effect of ethanol on BP and the risk of chronic consumption on the incidence of hypertension, particularly for Blacks. These effects do not support the putative cardioprotective effect of consumption of low-to-moderate amounts of alcoholic beverages. Mechanisms of chronic BP increase and the demonstration of long-term benefits of reducing alcohol intake as a means to treat hypertension remain open questions.