New research has found adding a little milk to your morning coffee may enhance the drink's anti-inflammatory properties. Across several studies food scientists have demonstrated how milk proteins can bind with antioxidants in coffee, amplifying any potential health benefits.
The research focused on a family of organic compounds known as polyphenols. Found in lots of foods, polyphenols have antioxidant effects, reducing oxidative stress in a human body. However, surprisingly little is known about how polyphenols interact with other molecules found in food.
In two new studies, researchers from the University of Copenhagen zoomed in on one specific polyphenol interaction – caffeic acid and chlorogenic acid (the two main polyphenols found in coffee) and cysteine (a key protein in milk).
The first new study looked at the effects of these polyphenol-protein combinations on immune cells in lab conditions. The researchers then artificially inflamed those immune cells to see how effectively the polyphenol-protein combo prevented inflammation.
The results were impressive, with the protein-spiked polyphenols turning out to be twice as effective at preventing inflammation in the immune cells, compared to polyphenols alone.
"In the study, we show that as a polyphenol reacts with an amino acid, its inhibitory effect on inflammation in immune cells is enhanced," said Marianne Nissen Lund, lead researcher on the study. "As such, it is clearly imaginable that this cocktail could also have a beneficial effect on inflammation in humans."
The next step in the research was to investigate whether this specific polyphenol-protein bond takes place in a coffee drink with milk. Here, Lund and colleagues effectively showed commercial coffee beverages do generate these novel bound molecules.
"Our result demonstrates that the reaction between polyphenols and proteins also happens in some of the coffee drinks with milk that we studied," said Lund. "In fact, the reaction happens so quickly that it has been difficult to avoid in any of the foods that we’ve studied so far."
Lund also suggests it is likely these beneficial polyphenol-protein interactions occur in other food combinations such as meats and vegetables or fruit smoothies with milk.
At this point the researchers have only observed these anti-inflammatory effects in cell experiments. Animal studies are the next stage for the researchers, and then potentially human investigations. According to Lund there is also ongoing work looking at ways to enhance polyphenol activity in human bodies by engineering them with proteins.
"Because humans do not absorb that much polyphenol, many researchers are studying how to encapsulate polyphenols in protein structures which improve their absorption in the body," said Lund. "This strategy has the added advantage of enhancing the anti-inflammatory effects of polyphenols."
The new studies were published in Food Chemistry and The Journal of Agricultural and Food Chemistry.
Source: University of Copenhagen
