Light-to-moderate drinkers tend to display an overall better cardiovascular health and longevity compared with abstainers or heavy drinkers _{(Klatsky et al., 1981; Maskarinec et al., 1998; Gaziano et al., 2000; Maraldi et al., 2006).} In addition to reducing the risk of atherosclerosis-related cardiovascular events, such as heart attacks, and angina pectoris _{(Camargo et al., 1997a; Dey and Choudhury, 1997; Frid, 2000; Samanek, 2000; Agarwal and Srivastava, 2001),} light-to-moderate drinking is also generally beneficial in minimizing the risk of stroke _{(Elkind et al., 2006),} peripheral artery disease _{(Camargo et al., 1997b)}, hypertension _{(Gillman et al., 1995; Thadhani et al., 2002)} and diabetes.

Source : Vascular Pharmacology Volume 57, Issues 2–4, Pages 69-71

Although many research groups* accept that light-to-moderate alcohol consumption can be beneficial to cardiovascular health, it's also clear that heavy use is detrimental to the same system.

The reasons for the beneficial effects are still not fully understood, and neither is the abrupt crossover into cardiovascular damage for heavier drinkers.

Further prospective studies in humans will have to further dwell on the underlying mechanisms for both beneficial and adverse effects of alcohol.

[source as above]

* Note: Not all alcohol research groups agree - some maintain that any amount of alcohol is damaging. ^{[link required]}

Also see :Alcohol intoxicationplugin-autotooltip__plain plugin-autotooltip_bigAlcohol intoxication

"Despite the fact that alcohol has been used and misused for hundreds of years, the mechanism of action of this simple molecule remains the subject of study. Alcohol use results in diverse behavioral effects, including intoxication, cognitive impairment, motor incoordination, tolerance and dependence, and these effects are likely due to its actions on multiple brain proteins. and Alcohol use and cancerplugin-autotooltip__plain plugin-autotooltip_bigAlcohol use and cancer

It's known that regular alcohol use - even at moderate levels - can increase the chances of developing various types of cancer.

After several decades of research, the increase in risk is now widely accepted to account for around 3.5% of cancer deaths worldwide. ( ref.