Some old news

The first record of brewing is to be found in the Sumerian civilisation in Mesopotamia about 6,000 years ago. In his review of the history of beer and its medicinal properties Antonio Gasbarrini, Associate Professor of Internal Medicine, Rome, outlined how the consumption of beer had increased health and longevity in ancient civilisations because of the vitamins and calories it contained. Many medical books contain references to beers properties as a diuretic, laxative and sedative drink. In agreement with Dr. Mack Mitchell, President of the Alcoholic Beverage Medical Research Foundation and Clinical Professor of Medicine at the University of North Carolina at Chapel Hill, professor Gasbarrini found strong evidence from observational studies that all alcoholic drinks are linked with lower risk of CHD (coronary heart disease). Thus a substantial portion of the benefit is due to the alcohol content of the drink. Here are some of the known mechanisms of effects of alcohol on risk of CHD:

·Alcohol increases serum level of HDL - the beneficial cholesterol.

·Alcohol decreases serum fibrinogen and increases serum TPA, thus thinning the blood.

·Alcohol decreases platelet adhesion making the blood less sticky.

·Low dose alcohol consumption protects the heart from future ischemia/reperfusion injury.

The same protective effects of alcohol are supposed to bring about the decrease in risk of ischemic stroke in moderate drinkers. The mechanisms, however, of the finding of a lower incidence of type 2 diabetes in moderate drinkers in several large population studies remain uncertain. An improvement of the moderate drinkers sensitivity to insulin seems to be the most likely explanation.

The antioxidant activity of beer

Whether you would order a pint of lager or a bottle of Newcastle Brown Ale in the pub used to be a matter of taste. These days you might also choose to consider the antioxidant activity of your favourite beer. Cereal grains are a good source of antioxidants and not surprisingly beer, which is made from malted barley, also contains antioxidants. Beers with a high antioxidant score generally have a high content of polyphenols which have been shown to have useful antioxidant properties. A research group from UMDS, Guys Hospital, London, has measured the total antioxidant activity (TAA) of 21 beer samples (Walters M et al. BRFI Quarterly, April 1997:18-20). The lagers had a TAA in the range of 1.00-1.50 mM while the stouts and dark ales - due to a higher content of polyphenols - led the antioxidant contest with TAAs in the range of 1.50-2.00 mM.

Dr. Pilar Codoñer Frach, University of Valencia, has studied the polyphenol content of 80 different beers. Basically, the final content of phenolic components of a beer depends on both the raw materials (malted barley and hops) and the brewing process. Dr. Frachs results confirmed previous reports of a higher polyphenol content of dark beers. "Bitter" style beers showed the highest levels of phenolic components. However, when moving from in vitro (test tubes) to in vivo (liver cell cultures) investigations Pilar Frach found no difference in antioxidant activity between light beer and dark beer samples. In conclusion her results show that beer is a product with an important antioxidant capacity - and you may feel free to choose between lager, ale and stout entirely according to your own taste.

Hop constituents - the spice in beer

Hops - an essential and unique ingredient of beer - contribute to the characteristic aroma and bitterness that makes beer the thirst quenching drink enjoyed by the consumer. Hops also act as a natural antibiotic, ensuring that the beer remains fresh to drink. Many hop constituents, however, also add health properties to beer, according to the research of Prof. Denis de Keukeleire, director of Pharmacognosy and Phytochemistry at Ghent University, Belgium. He has carried out research on hops and beer for 35 years.

2-4 grams of hops are needed for every litre of beer leading to ca. 100 mgs per litre hop-derived constituents which account for various medicinal properties:

·Sedative compounds with stress combating and sleep inducing properties.

·Flavonoids with potent antioxidant activity protecting against reactive oxygen species.

·Compounds with bacteriostatic, fungistatic and antiinflammatory action.

·Estrogenic compounds counteracting complaints related to the menopause.

·Bitter compunds which stimulates the digestive tract.

·Compounds with diuretic activity and beneficial effect against bladder complaints.

Most prominent among the bioactive hop constituents are the prenylated flavonoids that are transferred to a significant extent (up to 4 milligrams per litre) from hops to beer.

According to research in progress at Ghent University prenylated hop flavonoids have an effect on enzymes that affect the ratio of androgenic and estrogenic hormones in prostate cells with an inhibition of BPH (benign prostatic hyperplasia) as a possible result. The interesting finding from the test tubes of Ghent University is in accordance with recent results from the Health Professionals Follow-up Study: moderate alcohol consumption almost halved the American Health Professionals risk of BPH (Am J Epidemiol 1999;149:106-15).

Among the 20 compounds, which have been identified to date, 8-prenylnaringenin (hopein) appears to be the most intriguing compound with possible chemopreventive power:

·Inhibition of cytochrome P450 enzymes which mediate metabolic conversion of procarcinogens to carcinogens.

·Inhibition of human aromatase and 5a -reductase = a possible inhibition of prostate cancer.

·Inhibition of angiogenesis (formation of new blood vessels) = a possible inhibition of metastasis (spread of cancer from one organ to another part of the body).

Working with a screening program for chemo-preventive action of natural compounds Dr. Norbert Frank, senior scientist in the division of Toxicology and Cancer Risk Factors at Deutsches Krebsforschungszentrum in Heidelberg, found xanthohumol (XN) from hops to be a very promising agent. Laboratory experiments have shown that XN is protective at all levels of the carcinogenic process. Going from laboratory to animal experiments Dr. Frank could demonstrate that XN at very low concentrations prevented the early stages of carcinogenesis in cultured mouse mammary glands providing a first direct proof for its chemopreventive potential.

Vitamins in beer

Beer, primarily an enjoyable drink, also contains important vitamins. The main ingredient of beer is malt - sprouting barley and during malting the vitamin content increases. One litre of beer supplies the body with the following percentage of its daily requirement:

B6 17% Niacin 13%

B2 (riboflavin) 17% Biotin 17%

Panthothenic acid 8% Folate 10-45%

Dr. Caroline Walker, a biochemist for Brewing Research International is investigating the healthful aspects and nutritional value of beer. In the last decade it has become clear that increasing folate intake may provide protection against cardiovascular disease and cancer:

·High levels of homocysteine in the blood are linked with an increased risk of cardio-vascular disease. If folate supplies are adequate, homocysteine is converted to harmless methionine. Adequate folate intake could prevent 2-4% of cardiovascular deaths.

·An adequate level of folate in the blood is essential to the normal function of the enzymes maintaining healthy DNA. Lack of folates due to an inadequate folate intake may lead to DNA damage and cancer.

Unfortunately folate is one of the vitamins most likely to be lacking in Western type diets typically low in fruit and vegetables. Caroline Walker pointed out that beer accounts for 10% of the total folate intake by adults in the UK. The folate content of 1l beer corresponds to the folate content of 300g tomatoes. A study of 2290 men from Wales found that alcohol consumption was linked to lower homocysteine levels. A similar population study from the Czech Republic found beer consumption linked to lower homocysteine levels and higher folate levels (European Journal of Clinical Nutrition 2001;55:605-9).

Beer, bones and silicon

When the question is what beverage to drink in order to get strong bones milk, as an important source of calcium , clearly has the upper hand. In his lecture Dr. Jonathan Powell, Senior Lecturer and head of a research group on mineral metabolism at the Dept. of Gastro-intestinal Research, St Thomas Hospital, London, drew attention to silicon - an essential element for growth and development, especially of bone and connective tissue.

Recent work has shown that a supply of low levels of soluble silicon promote bone fracture healing. Normal dietary silicon intake in adults is 20-50mgs/day. The content of 10-40 mgs silicon in a bioavailable form (orthosilicic acid) makes beer a major dietary source of silicon. In several population studies a moderate intake of alcohol was associated with a higher BMD (bone mineral density) = stronger bones. Whether dietary silicon and moderate beer drinking protects against reduced BMD in humans and therefore, protects against osteoporosis is presently under investigation.

In a paper published in the Lancet 1977 Klaus Schwarz presents a logical argument for the hypothesis that lack of silicon may be an important aetiological factor in atherosclerosis. Silicon is essential for growth of connective tissue and unusually high amounts of bound silicon are present in the arterial wall, especially the intima. In atherosclerotic arteries silicon levels are greatly reduced. Industrial refinement can greatly reduce the amount of silicon in foods. Hence the hypothesis that lack of bioavailable silicon in modern diets may play a part in the promotion of atherosclerosis, and silicon may exert a protective effect against CVD. Klaus Schwarz found an inverse relation between silisic acid in drinking-water and the prevalence of CHD in Finland. They never investigated the silicon content of beer and, therefore, they missed the opportunity to look for an inverse relation between the silicon intake of beer drinkers and CHD in beer drinking countries like Germany and the Czech Republic.

The health benefits of moderate beer consumption

In his capacity as a General Practitioner it was the task of the author of this paper to pass on the lectures of the symposium to the delegates in an understandable form. The key word for a physician outlining the health benefits of moderate beer consumption is moderation:

To drink moderately is to drink within the limits set by your health, your economy and your obligations towards your family and friends: 1-2 drinks (1 drink = 12 gms of alcohol) a day for most women and 1-3 drinks a day for most men.

Bar-drinking may end up as binge-drinking - food in the stomach will help to protect you from alcohol intoxication.

·One drink for a women is almost the equivalent of two drinks for a man as women have more fatty tissue per kg body weight than men; that leaves men with more body water (ca. 10 liters) to dilute their drinks than women. Males also have a more efficient "First-Pass Metabolism" of alcohol than females due to a larger concentration of alcohol dehydrogenase in the stomach.

Is beer a boon to old people? Beer improves appetite, promotes secretion of gastric juice, aids digestion and may reduce the risk of stomach ulcers caused by Helicobacter pylori infection. Regular drinkers of beer (and wine) seem to be less prone to developing dementia. At bedtime beer is cherished as a mild sedative. Moderate beer consumption is likely to reduce the risk of maturity-onset diabetes and a recent investigation has shown a reduced risk of heart failure in light drinkers. The result of a moderate intake of beer for a group of elderly Australian beer drinkers was a 7.6 months increase in survival.

Is red wine better than beer? The results from recent research has directed attention to a link between beverage choice and lifestyle showing that beer drinkers in some countries tend to make unhealthier lifestyle choices than wine drinkers. Therefore the apparent good health of wine drinkers compared to beer drinkers in some studies seem to be a lifestyle effect and not a beverage effect. In Germany, where beer is the common alcoholic beverage, all research show that moderate consumption of beer protects against CHD.

In conclusion Beer is a well-balanced, low-alcohol beverage with significant levels of vitamins (in particular folates), minerals and silicon. Regular, moderate beer drinking may be a part of a healthy lifestyle together with wholesome food, exercise, keeping your weight down and not smoking.