FDA Study Finds Filtering Beverages May Add Heavy Metals

Beer and wine that is filtered with diatomaceous earth may be transferring heavy metals such as arsenic, lead and cadmium into beverages, endangering consumers’ health, according to a study by researchers for the Food and Drug Administration.

The FDA’s Center for Food Safety and Applied Nutrition tested three types of diatomaceous earth, or DE, used to filter beer and wine to test a hypothesis that it could be contributing to elevated levels of heavy metals in food and wine that have been found in some studies. The researchers also wanted to find out of altering the filtering conditions could reduce the transfer.

Beer and wine producers usually filter their products to ensure to improve clarity and remove impurities.

The researchers found all three types of DE tested contained arsenic and smaller amounts of lead and cadmium, and those metals passed into the filtered beverages. One DE sample increased arsenic levels 3.7 to 7.9 times the amount found in unfiltered beer and wine, according to the study, which was published in the Journal of Agricultural and Food Chemistry.

Those levels were above the safe limit of 10 parts per billion proposed by the FDA for apple juice, the researchers said.

But the arsenic levels decreased when beverages were exposed to less DE, the pH of the liquid was altered or the DE was washed before hand.

The researchers also measured the amount of heavy metals in commercial beer and wine samples. In most cases they detected arsenic in samples, but below the 10 ppb level considered safe. However, two wine samples contained 18 and 11 ppb arsenic.

The Department of Energy, the Oak Ridge Institute for Science and Education and the FDA funded the study.