Beer : Health and Nutrition

The Impact of Alcohol on Health 127
It seems that not only does limited alcohol intake reduce the risk of heart attack, but
even after myocardial infarction, the moderate consumption of alcohol reduced the risk
of a subsequent episode (Muntwyler et al. 1998).
Predictably, critics of these various claims have asserted that the phenomenon is an
artefact arising from the fact that some of the non drinkers were either not consuming
alcohol because of ill health or were previous heavy consumers who had stopped
drinking for health reasons (‘sick quitters’) (Shaper 1990). However studies that have
painstakingly eliminated such purported problems have continued to demonstrate the
validity of the U- or J-shaped curves (Criqui 1990, 1996; Kannel & Ellison 1996).
Dawson (2000) stresses that alcohol dependence nulli es any bene t from moderate
drinking. Excessive consumption of alcohol has unquestioned detrimental effects
(Poikolainen 1996). For example, Kauhanen et al. (1997) demonstrated the adverse
impact on all causes of mortality, including myocardial infarction, of binge drinking
of beer. Britton and McKee (2000) highlighted how the apparently contradictory nding
that alcohol intake in certain populations (e.g. Russia) was positively correlated
with cardiovascular disease could in fact be linked to binge drinking. This emphasises
the importance of moderation in terms of not only the amount of intake but also the
frequency.
Remarkably, however, Mukamal et al. (2003) showed from a study of 38,077 male
health professionals over a 12-year period that men who consumed alcohol 3–4 or 5–7
days per week had a decreased risk of myocardial infarction when compared to those
who drank less than once per week. They found that the risk was similar for men taking
10 g alcohol per day or 30 g or more per day, and furthermore it didn’t matter whether
the beverage was beer, red wine, white wine or spirits. In other words, these authors
would claim that the frequency of drinking has as much, if not more, effect than the
absolute level of drinking.
At least two components of alcoholic beverages have been suggested as being the
key factors in the reduction of atheroma: antioxidants and the alcohol itself.
It is understood that alcohol increases the concentration in blood serum of HDL cholesterol
– i.e. it lessens accumulation of cholesterol in blood vessels (Hulley & Gordon
1981; Thornton et al. 1983). It has also been suggested that alcohol reduces the risk of
atherosclerosis by lessening the tendency of blood platelets to aggregate in blood clotting
(Renaud et al. 1992; Hendriks & van der Gang1998) and bene cially impacting
clotting/ brinolysis mechanisms (Kluft et al. 1990; Ridker et al. 1994). Alcohol may
decrease platelet stickiness (Mikhailidis et al. 1983), lower levels of brinogen (Ridker
et al. 1994) and promote the release of plasminogen activator (Laug 1983).
Components of alcoholic beverages other than alcohol may also combat coronary
heart disease (Klatsky 1999), and these include the polyphenols (Halpern et al. 1998).
Beer, wine and spirits seem to have similar effects on plasma HDL (Parker et al. 1996;
Rimm et al. 1999), which may argue against agents such as polyphenols, which are