Coffee with milk has anti-inflammatory properties. The combination of milk proteins and antioxidant polyphenols in coffee doubles the anti-inflammatory effect of polyphenols on immune cells, according to a new study by researchers at the University of Copenhagen.
Can a cup of coffee with milk be an anti-inflammatory 'medicine'?
Yes, it can, according to a new study by researchers at the University of Copenhagen, thanks to the marriage of the proteins contained in milk with the polyphenols of coffee.
Polyphenols are a group of naturally produced antioxidant substances beneficial to the human body as they help reduce oxidative stress which leads to inflammation. These natural substances are contained in many fruits and vegetables, coffee, tea, red wine and beer.
However, while these substances are known, they remain unknown to a large extent as up until now very few studies have looked at what happens when polyphenols react with other molecules such as proteins found in foods we eat every day.
The marriage with amino acids
A new study published in the 'Journal of Agricultural and Food Chemistry' and conducted by researchers from the Department of Food Science and the Department of Veterinary Medicine at the University of Copenhagen in collaboration with experts from the Technical University of Dresden in Germany, has put under the microscope how polyphenols behave when combined with amino acids, the building blocks of proteins.
A beneficial cocktail
Based on findings related to experiments on immune cells, when polyphenols are combined with amino acids, their anti-inflammatory action is enhanced.
"We estimate that this 'cocktail' may also have a beneficial effect on suppressing inflammation in humans," said study leader Professor Marianne Nissen Lund from the Department of Food Science at the University of Copenhagen.
"We are proceeding to further investigate this relationship, initially in animals. We hope that funding will then be found in order to also examine the effect on humans."
Experiments on cells
To study the anti-inflammatory effect of the combination of polyphenols and proteins, the researchers induced artificial inflammation in immune cells. Some cells received different doses of polyphenols that had previously reacted with an amino acid, while other cells received the same doses of polyphenols alone.
As it turned out, the cells into which the combination of polyphenols and amino acids had been introduced were twice as effective at fighting inflammation compared to the cells to which only polyphenols had been added. The next step for the research team is to study whether the same effect exists in animal models.
Anti-inflammatory action in the cup AND on the plate
Previous studies by the same group had shown that polyphenols bind to proteins in meats, milk and beer. In their new study, the researchers looked at whether these antioxidants also bind to coffee that contains milk – which makes sense as coffee beans contain many polyphenols while milk is rich in proteins.
"According to our results, the reaction between polyphenols and proteins was occurring in some of the milk coffee drinks we examined. In fact, this reaction happens so quickly that it could hardly not happen in all the food categories we have studied so far," noted Dr Nissen Lund.
Meat with vegetables and smoothies are also anti-inflammatory
Dr Nissen Lund therefore estimates that the reaction between proteins and polyphenols and the resulting beneficial anti-inflammatory effect will also occur when other protein foods are combined with foods rich in polyphenols, such as fruits and vegetables.
"I imagine something similar happens in a dish that contains meat with vegetables, or in a smoothie that contains milk or yoghurt."
Locking polyphenols into protein structures
It is noted that the scientific community and the food industry have understood the significant advantages of polyphenols for human health. So they work on adding the right amounts of polyphenols to foods to provide the maximum possible benefits to the human body.
"Given that humans do not absorb large amounts of polyphenols, many researchers are currently looking at how they can 'lock' polyphenols into protein structures in order to increase their absorption by the human body.
"This strategy is expected to have the added benefit of enhancing the anti-inflammatory action of polyphenols," concluded Dr Nissen Lund.