Beer, Arsenic and Other Things Found in the Brew
When the bartender hands you a foamy glass of beer, some arsenic is likely lurking in the golden brew. A recent study discovered why some German beers have higher than acceptable levels of arsenic. That information and some other facts about the brew may be of interest as we head into the hot summer months.
What’s in your beer?
At the 245th National Meeting & Exposition of the American Chemical Society, a scientific team headed by Mehmet Coelhan, PhD reported that a filtering process was behind a mystery concerning beer. It seems that experts who were monitoring beer samples found high levels of arsenic in German beers even though the water used to make the beer (which normally contains a minute amount of the heavy metal) contained less than the levels measured.
The World Health Organization safety limit for arsenic in water is 10 micrograms per liter. However, some beers tested in Germany revealed higher levels. An evaluation of the ingredients and processing showed that the material used to filter the beer to give it a clear appearance was in fact adding arsenic to the brew.
That filtering material is kieselguhr, or diatomaceous earth, which is composed of the microscopic remains of fossilized algae. In addition to serving as a filtering material for beer and wine, diatomaceous earth (which is available in various grades) is also used to treat fleas in dogs and cats as well as help eliminate worms and toxins from the body.
The good news from the study by Coelhan’s team is that the levels of arsenic “were only slightly elevated, and it is not likely that people would get sick from drinking beers made with this filtration method.” Brewers who wash kieselguhr with water before use can remove the arsenic.
What else might you find in your beer?
In an Italian study published in 2008, the researchers reported on the content of arsenic, cadmium, and lead in 19 beers available in Italy, which came from other countries as well, including Germany, Ireland, Japan, Belgium, Mexico, and Spain. The authors concluded that while drinking beer may contribute these heavy metals to the diet, exposure was “unlikely to constitute a hazard to the consumer’s health.”
Although contaminants such as arsenic can slip into beer during the production process, the natural ingredients themselves are a source as well. The amount of heavy metals present in the cereals and hops depends on the type of soil in which they are grown, the organic matter composition of the soil, the chemicals applied to the crops, differences between varieties of cereals, and recycling of sludge to the land, among other factors.
Generally, hops contain a higher level of heavy metals than do cereals, according to the study reported in the Journal of the Institute of Brewing. However, the total amount of toxins in hops is still far lower than the hazardous limits for human consumption.
Contaminants naturally found in the raw ingredients used in the making of beer, such as aflatoxins and fumonisins in corn and barley should not be a problem when brewers follow established regulations. Aflatoxins are chemicals produced by certain mold fungi and are known to cause cancer in animals. The Food and Drug Administration allows aflatoxins at low levels in foods because it considers them to be “unavoidable contaminants.”
Fumonisins are another type of toxin found in corn wherever it is grown. They have been suggested to be involved in causing esophageal cancer in humans.
A study in Food Additives & Contaminants on the presence of aflatoxin B1 and fumonisin B1, however, explained that “the contribution of a moderate daily consumption of beer to [to these two toxins] intake does not contribute significantly to the exposure of the consumer.”
A recent study in the International Journal of Cancer analyzed the risk associated with the presence of 15 different known and suspected cancer-causing substances found in alcoholic beverages, including beer. Among the carcinogens studied were acrylamide, aflatoxins, arsenic, cadmium, ethanol, lead, and formaldehyde.
They concluded that “the focus should be on reducing alcohol consumption in general rather than on mitigative measures for some contaminants that contribute only to a limited extent (if at all) to the total health risk.”
Coelhan seems to agree. He noted that the real dangers associated with drinking beer lie with the amount of alcohol people consume. “The risk of alcohol poisoning is a far more realistic concern,” he stated, than exposure to arsenic and other contaminants.
American Chemical Society/Medical News Today
Donadini G et al. Arsenic, cadmium and lead in beers. Journal of the Institute of Brewing 2008; 114(4): 283-88
Lachenmeier DW et al. Comparative risk assessment of carcinogens in alcoholic beverages using the margin of exposure approach. International Journal of Cancer 2012 Sep 15; 131(6): E995-1003
Pietri A et al. Transfer of aflatoxin B1 and fumonisin B1 from naturally contaminated raw materials to beer during an industrial brewing process. Food Additives & Contaminants 2010 Oct; 27(10): 1431-39