Levels of common minerals and heavy metals in Alberta's milk are safe for human consumption, according to a new study out of the University of Alberta.
The study, the first of its kind in Canada, fills in a knowledge gap since no safety guidelines have been specifically established for measuring toxic mineral levels in milk, said lead author and U of A nutritional immunobiologist Burim Ametaj.
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The closest related measurement is a Health Canada list of maximum levels for chemical contaminants in foods that doesn't include minimum risk levels for minerals or heavy metals, he noted.
"Now we know what we are getting," he said. "The good news is, the minerals are below minimum risk levels, so we are drinking safe milk. We couldn't say this before the study; we just didn't know."
Milk quality in Alberta is measured by the number of immune cells found in milk to indicate mastitis in a cow, and by total lipids, protein and lactose content, to determine what the producer will be paid.
However, there is no measurement of mineral levels, and while minerals like calcium and phosphorus are good for human health, heavy metals like lead, arsenic and aluminum are not.
The research measured concentrations of 20 minerals in whole raw milk from 26 dairy farms across Alberta. The levels of minerals were then compared with recommended daily intakes or minimal risk levels from several food safety agencies, including the World Health Organization, the U.S. Agency for Toxic Substances and Disease Registry and the European Food Safety Authority.
The study lays out exact concentrations of minerals found in a 300 millilitre glass of whole milk. Though the study measured milk in its raw, whole form, the processed products sold on store shelves have similar minimal levels, Ametaj noted.
Even though soil, water and feed composition varied for dairy farms across the province, analysis showed that all the minerals and heavy metals were below minimal risk levels across the board, although one—chromium—was higher than the other metals, but still within the recommended allowance in one daily glass of milk.
"At these minimal levels, heavy metals pass through the body and don't harm us," said Ametaj.
In fact, there are trace levels of heavy metals in water, plants, soil and the supplements fed to food animals, he noted.
"They are everywhere, it can't be avoided," Ametaj said.
The research findings provide valuable information that can be used by dietitians and medical professionals in counselling their patients, and by food and animal scientists and milk processors, Ametaj believes.
"Milk and dairy are part of our diets, so we need to know how much we are getting in minerals per day, and also if there are any toxic levels," he said.
