U of A researchers create ‘encyclopedia of milk’
New online database lists more than 2,000 chemical compounds in one of the world’s most popular drinks—including 168 never before reported.
By BEV BETKOWSKI
What’s in that glass of milk you’re drinking? Now you can find out, thanks to a new database created by University of Alberta researchers.
The newly launched, one-of-a-kind Milk Composition Database (MCDB) lists more than 2,000 compounds found in one of the world’s most popular drinks.
“It’s a bit like an encyclopedia of milk,” said U of A biologist David Wishart, who created the free, comprehensive online reference with U of A immunobiologist Burim Ametaj and other U of A researchers.
The database brings together scattered findings drawn from their research of 150 existing studies about milk composition worldwide, along with results from chemical analysis in Wishart’s lab of various substances in local milk varieties, including metal ions, vitamins, organic acids and amino acids.
Through five years of work, the researchers were able to identify 2,355 compounds, including 168 never before reported in milk.
Comparing nutritional value
Database users can search for and sort through the compounds, exploring them in several ways—for instance, looking into detailed nutritional differences between whole and skim milk, learning how it differs from other animal milk or finding out what’s actually in milk.
“Many people might wonder about new compounds that have health claims. With this database, you can look them up online very easily to see if they’re found in milk,” Wishart noted.
The list allows nutritionists to closely compare the differing levels of essential vitamins and minerals in milk with varying levels of fat content, ranging from skim to three per cent varieties, Ametaj noted.
“When you remove fat from milk, you’re taking away vitamins A, D, E, K and even vitamin C, so that can be important for tailoring nutritional counselling.”
The database can be a launchpad for further exploration related to health, Wishart added. “We’re hoping it will inspire more research into milk and milk products.”
Identifying chemical markers for milk—and other foods—would provide much stronger data for health researchers, who could take blood, hair or urine samples for diet analysis instead of using traditional surveys, which are only generally accurate because they rely on human memory, he said.
“We need the ability to properly measure what we eat, to link nutrition to health and disease.”
The MCDB is also useful to veterinarians, milk producers and processors, said Ametaj, who studies dairy cattle health.
“We examine milk for diagnosis of diseases like mastitis in dairy cows, and the database provides a way to compare samples from sick cows with the profile of healthy milk.”
A full snapshot of milk may never be possible, Wishart said, because many compounds are still to be discovered.
“We probably won't be able to discover them all, at least not in the next 10 to 20 years. Milk is so chemically complex that there are probably reactions going on all the time, so the actual chemical content in milk is always subtly changing.”
There may be compounds that are unique or exist in such low concentrations that it’s not known how to measure them or what they really are, he said.
Milk from different dairy cow species will also have different compounds, “so unless we were very thorough with characterizing milk from every breed of cow, we would still miss some compounds.”
That said, it made sense to create a database, Wishart said.
“Given the importance of milk as a foodstuff and its fundamental importance to our lives, it’s important to know what’s there.”
There’s a huge upside to learning as much as possible about a drink that’s as common as soda or water, is used in a wide range of dairy products and is a global business worth half a trillion dollars, said Wishart.
“The more we know about these compounds, the more we can potentially improve milk.”
The database will be updated continuously, Wishart said.
Ultimately, the researchers hope to set up similar databases for goat and sheep milk as well as wine, beer and marijuana, “to know what we are consuming,” he added.