Based on previous research that suggests beer probably contains high levels of bioavailable silicon, scientists at the University of London in the UK investigated the range of beer-silicon levels and the extent of absorption in humans.
They examined the silicon content of 76 different beers and then estimated the silicon absorption from beer in 17 healthy volunteers, nine males and eight females with a mean age 25 years.
They found that the silicon content of beer varied from 9 to 39 mg per litre. Although the researchers say the reason for the variability is not clear, they suggest that the final beer silicon levels may be due to variations in the way the malted barley is processed.
No link was traced between the silicon content of beer and the type of beer - wheat beer, stout, ale, lager, bottled, canned or draught, the concentration of ethanol or country of origin.
Subjects' blood and urinary silicon levels were measured after consuming comparable amounts of beer, a soluble silicon solution, ethanol or water. The scientists found that the subjects' blood and urinary silicon levels increased considerably and similarly following the ingestion of beer or the soluble silicon solution, but not with the ingestion of ethanol or water.
"We already knew that beer was likely to contain the highest source of silicon per serving because its manufacture uses the husk of the grain, where the silicon is contained," said lead researcher Dr. Jonathan Powell. "Now we have confirmed that beer is a readily bioavailable source of silicon. Unlike some other high- silicon foods, the silicon in beer is readily absorbed because it exists as soluble silicate," he added.
The World Health Organisation has defined osteoporosis, a disease where bone is lost more rapidly than it is replaced which can lead to a predisposition to fractures, as the second leading health care problem after cardiovascular disease.
The findings from the UK study, published in the March issue of the British Journal of Nutrition, follow hot on the heels of findings released in the February 2004 issue of the Journal of Bone and Mineral Research, that found a striking relationship between the intake of dietary silicon and bone mineral density in the hip sites of men and pre-menopausal women.
Beer may well possess other potential health benefits with Japanese researchers reporting last month that some of the components in beer appear to protect against development of colon cancer. A team from Japan's Kirin Brewery carried out a 42-week experiment on 344 male Fischer rats with chemically induced colon cancer. Intake of beer decreased tumour incidence by 22 per cent and decreased the number of neoplastic lesions, including adenocarcinomas and adenomas (benign and malignant tumours), by 44 per cent, they report in the International Journal of Cancer (vol 108, issue 3, pp404 - 411).