Wine that maketh glad the heart of man.
The Book of Psalms, 104:15
Despite an ever increasing amount of evidence that a moderate consumption of alcohol has a beneficial effect on many aspects of health, the vast majority of work concerns the effect on coronary heart disease, and that easily defined indicator of general ill health, death.
What is coronary heart disease?
With increasing age, atherosclerotic plaques form within the walls of the blood vessels. These plaques are already present in primary school age children. With time, plaques in the coronary arteries (three vessels that supply the heart with blood) may impede the blood supply to the heart muscle. Heart muscle with an unsatisfactory blood supply may become ischaemic (starved of oxygen), particularly during exercise. This manifests as chest pain, known as angina. Should one or more coronary arteries become suddenly blocked, by rupture of one the plaques and the formation of blood clot in and around it, the blood supply to a part of the heart muscle is lost completely. This section of muscle then dies. This is a myocardial infarction, commonly referred to as a heart attack.
This whole spectrum of disease can be referred to as coronary heart disease or ischaemic heart disease.
Can alcohol help prevent this?
The largest studies provide the best evidence. In 1997 Thun et al demonstrated a reduced risk of death from CHD with up to two drinks per day, but an increased death rate with more than three drinks per day. This study involved a staggering 490 000 adult Americans, and was adjusted for confounding variables.
In 1990 Boffetta et al published work demonstrating a decreased risk of death with up to two drinks per day, but no benefit from drinking any more. This involved 276 802 men aged 40- 59, and was adjusted for age and smoking, but not for other confounding variables.
Gaziano et al, publishing in 2000, studied 89 299 US male physicians. Up to one drink per day conferred a lower overall mortality. There was no benefit from drinking more than two drinks per day.
In 1995 Stampfer published work involving 85 709 women aged 34- 59. There was a lower risk of death in drinkers consuming 18 drinks per week (about 2.5 drinks per day). Drinking more than this resulted in an increased risk of death (from cancer and cirrhosis). This study was adjusted for confounders.
Doll studied 12 321 British doctors, publishing in 1994. The lowest risk of death occurred with one to two drinks per day. CHD deaths were reduced in all drinkers.
All these studies agree: reduced death with moderate consumption (up to two-to-three drinks per day), with no benefit and often increased risk of death with higher levels of consumption.
There are other supportive studies, which demonstrate lower rates of CHD related death with increasing levels of alcohol intake, but do not study overall death rate and are therefore not applicable in real life. These are Valmadrid (983 diabetics, 1999), Klatsky (128 934 Californians, 1997) and Rimm (51 529 male physicians, 1991).
Drinking heavily reduces your risk of dying from CHD even further, but overall you are more likely to die because of increased risk of cancer, liver disease and trauma.
These findings do not represent a reason to take up drinking if you currently abstain, but they do represent a reason to cut back if you imbibe heavily.
If you are worried about your risk of heart disease (perhaps because of family history), don't smoke, take some exercise and eat a balanced diet. For advice about any of these, see your general practitioner.