Beer: is it good or bad for your health?

The history of beer goes back to its discovery in Mesopotamia around 4000BC. The drink has been an important dietary component for people of all ages, and has also been used historically for a range of medicinal purposes, including as a mouthwash, an enema and a vaginal douche, and to treat wounds.

In ancient times beer was neither carbonated nor flavoured with hops. The latter modification began in the eighth century AD. It has been claimed that beer is now the world’s most popular herbal remedy.

Beer is manufactured from malted barley and hops. The wort is obtained either by infusion or decoction, and fermentation is facilitated by either wild yeast or the addition of yeast. The hops content has long been accepted as having a preservative action.

Styles of beer available now include lagers, ales, wheat beers, stouts, fruit beers, porters and steam beers. Each involves a different brewing technique. 

The popularity and marketing hype of beer has extended beyond the boundary of drinking. Extracts of beer are now found in a wide variety of non-beverage consumer products, including cosmetics and shampoos, and foods such as cheese. And spas are now offering beer baths and beer massages.

Intensive advertising and sponsorship of beers at an international level has increased sales dramatically and stimulated consumption. Individuals who are excessive consumers of beer (and other alcoholic drinks) are often affected by adverse health issues, particularly if they also have a poor dietary intake coupled with lack of exercise. 

Excess consumption of alcoholic drinks is now considered to be both dangerous and antisocial, both for the consumer and for the wider population.

However, research suggests that moderate consumption may have positive health benefits. 

Constituents of beers

Alcohol

The alcohol content of beers ranges from 0.05 per cent in low alcohol (“alcohol-free”) beers to more than 10 per cent, particularly in some Belgian beers. The usual range is of the order of 3 to 6 per cent.

Nutrients

Beer is well known to contain a large number of nutritive components, including vitamins (particularly B vitamins) and minerals (particularly selenium and silicon). It also has a high potassium/sodium ratio (usually in the ratio of 4:1), and contains from 0.4 to 6.2 per cent of dietary fibre.

Calories

The ethanol content in beer contributes substantially to its calorie content, at the level of 7Kcal/g.

Twenty-five per cent of the starch in beer is partially degraded and present in a non-fermentable form, which adds further calories. These latter carbohydrates are largely absent from “diet” beers.

Herbs and spices

Hops, the female flower cones of Humulus lupulus, are used in the manufacture of beer to impart a bitter taste.

As with other bitter tasting drinks, beers are known to stimulate the appetite.

In addition to malted barley and hops, some specialist beers have added herbs and spices (see Table below).

These additives contribute to the overall flavour palate, but it is not known whether they contribute to any biological activity at the levels present.

Most of these additives are either traditional or modern gimmicks (eg, ginseng).

The constituents in the traditional recipes are mainly lower terpenoids, phenylpropanoids or fruit flavours, and these may act as mild carminatives.

Recent research on healthful effects

In published research on the overall health effects of beer it is difficult to separate the effects of the alcohol from those of the constituent phytochemicals, which are mainly phenolic compounds.

The effects of beer consumption in a number of disease states, including coronary heart disease and cancer, have been reported, along with a range of activities of individual phytochemicals.

About 30 per cent of the polyphenols of beer wort are derived from the hops. It has been discovered that hops contain 0.5mg/kg trans-resveratrol, and also a number of piceid (resveratrol glucoside) isomers. 

The beneficial activities of trans-resveratrol include antiplatelet, anti-inflammatory, oestrogenic, cardioprotective, antitumour and antiviral properties. And trans-piceid (2mg/kg) is believed to limit the elevation of lipid concentration, and inhibit eicosanoid synthesis.

Xanthohumol

Xanthohumol is the major flavonoid found in hops, and human exposure is mainly through drinking beer. It has been demonstrated that xanthohumol may prevent colonic carcinogenesis, and also suppresses CYP1A2, which catalyses the metabolic activation of a number of procarcinogens and cyclo-oxygenase-2, the latter being a key enzyme involved in cancer progression.

It also induces detoxification enzymes to suppress carcinogenesis. Humulone from hops has also been found to suppress cyclo-oxygenase-2 and prevent angiogenesis associated with tumour progression.

Xanthohumol has been been demonstrated to have a range of activities against cancer initiation in in vitro studies, and 8-prenylnaringin, another flavonoid present in hops, is the most potent oestrogen receptor a agonist found in plants, having phytoestrogenic activity.

The latter constituent, therefore, could have a potential role in prevention or treatment of post-menopausal symptoms, such as hot flushes and osteoporosis, and is present in far greater levels in bitter beers than in lagers.

There has been some interest in the effects of beer consumption on osteoporosis. Femoral bone loss was inhibited in ovariectomised beer-fed rats but not in rats fed alcohol alone or hop-free beer. An active component was identified as isoxanthohumol, but 8-prenylnaringin was shown to have no effect.

Polyphenols

Much research has been sponsored by breweries in response to claims for the benefits of wine, and often this has been focused on polyphenol composition.

It is often reported that moderate consumption of alcoholic drinks affect indicators of atherosclerosis, such as improving lipid metabolism, increasing antioxidant activity, and improving coagulant status.

It is also believed that these changes decrease mortality and morbidity of coronary artery disease, and it is widely thought that these effects are due to the alcohol content alone. 

Research on the effects of lyophilised beer on lipid metabolism and antioxidant activity in the serum of rats has shown a reduction in total cholesterol and triglycerides and increased levels of high density lipoprotein cholesterol. Volumes as small as 6ml were used.

The authors’ conclusion was that the phenolic portion of the lyophilised beer residue was responsible for the effects. 

The higher polyphenol content of some beverages is thought to be responsible for greater antioxidant activity. However, it has been found that although wines have a greater phenolic content than beer, it is beer that possesses the higher antioxidant activity. 

Analysis has shown that beer contains higher levels of proanthocyanidins, epicatechin and ferulic acid than wines, and that levels of quercitin, ?-coumaric and gallic acids were similar, suggesting that higher levels of epicatechin and ferulic acid are responsible for the observed effects. Ferulic acid has also been shown to be readily absorbed in the human body.

A recent clinical trial involved 42 hypercholesteraemic male non-drinkers who consumed 330ml of beer daily for 30 days. The results included significant improvement of plasma lipid levels, and an increase in plasma antioxidant and anticoagulant activities.

A population-based sample of 5,865 older adults from four communities in the US found that alcohol intake (assessed by number of drinks, whether beer, wine or spirits) was associated with lower levels of inflammatory markers in this patient group, which was free from cardiovascular disease.

Further investigation of the comparative effects of the alcohol or phenolic constituents has been carried out using commercial de-alcoholised beer.

Acute consumption of three litres of beer by healthy young adults showed inhibition of thrombogenic activity and, consequently, a beneficial effect which could help prevent the development of coronary artery disease.

A population study on the influence of beer consumption on folate and homocysteine concentrations revealed that moderate consumption causes increased folate levels, leading to normal levels of homocysteine in a population with limited folate intake. This suggests that beer may have a protective effect against cardiovascular disease in some populations.

Aluminium has been implicated as a causal factor contributing to Alzheimer’s disease, and it is understood that silicon can affect the bioavailability of aluminium.

Research in mice has shown that the presence of moderately high levels of silicon in beer has been able to reduce the uptake of aluminium in the digestive tract and, therefore, slow the accumulation in the body, including in brain tissue.

A large prospective study has been reported on the effects of moderate beer consumption. It concluded that beer is not associated with an increase in body mass index.

Detrimental effects of beer

Studies have been carried out to quantify the harmful effects of beer consumption. Most of the detrimental effects relate to high alcohol levels resulting from heavy consumption of beer. 

Acute alcohol-related incidents included pancreatitis, excess blood alcohol, poisoning and suicide. Chronic effects included malignant neoplasms, diabetes, hypertension, tuberculosis, pneumonia, influenza and chronic pancreatitis.

An ecological study carried out in Louisiana, US, found that populations in districts with high levels of beer consumption had higher premature mortality — with 24 per cent of deaths related to beer drinking. Beer consumption was independently associated with homicide, liver diseases and cardiovascular disease.

The risk of cancer in Danish brewery workers receiving 2.1 litres of free beer daily was investigated in 13,051 subjects. Reported outcomes were that there was a significantly increased risk of cancers, particularly in the buccal cavity, digestive organs, respiratory system and urinary system, and slight increase in colon and rectum cancers.

However, a study in eastern France found that moderate drinking of both beer and wine was associated with a lower mortality from all causes, and both drinks reduced the risk of cardiovascular death.

Conclusions

Beer is an enjoyable drink taken in moderate amounts, and may have positive effects on health. A traditional diet of beer and fresh foods may be better than the highly promoted soft drinks and convenience foods.