The latest scientific evidence on the benefits of moderate beer
consumption was presented to members of the European Parliament,
the press and the public at the 2nd Beer & Health Symposium in
Brussels 18 October 2001. In her opening speech Mrs Marianne Thyssen,
Member of the European Parliament, stressed the importance of
moderation as the condition of the positive contribution of beer
to a healthy lifestyle.
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. |