Coffee with milk may have an anti-inflammatory effect in humans, a new study shows.
Researchers found that a combination of proteins and antioxidants doubles the anti-inflammatory properties in immune cells. They hope to be able to study the health effects on humans.
Whenever bacteria, viruses, and other foreign substances enter the body, our immune systems react by deploying white blood cells and chemical substances to protect us.
This reaction, commonly known as inflammation, also occurs whenever we overload tendons and muscles and is characteristic of diseases like rheumatoid arthritis.
Antioxidants known as polyphenols are found in humans, plants, fruits, and vegetables. This group of antioxidants is also used by the food industry to slow the oxidation and deterioration of food quality and thereby avoid off flavors and rancidity. Polyphenols are also known to be healthy for humans, as they help reduce oxidative stress in the body that gives rise to inflammation.
But much remains unknown about polyphenols. Relatively few studies have investigated what happens when polyphenols react with other molecules, such as proteins mixed into foods that we then consume.
In a new study, researchers investigated how polyphenols behave when combined with amino acids, the building blocks of proteins. The results have been promising.
“In the study, we show that as a polyphenol reacts with an amino acid, its inhibitory effect on inflammation in immune cells is enhanced,” says Marianne Nissen Lund, a professor in the food science department at the University of Copenhagen, who headed the study in the Journal of Agricultural and Food Chemistry.
“As such, it is clearly imaginable that this cocktail could also have a beneficial effect on inflammation in humans. We will now investigate further, initially in animals. After that, we hope to receive research funding which will allow us to study the effect in humans.”
Twice the inflammation-fighting power
To investigate the anti-inflammatory effect of combining polyphenols with proteins, the researchers applied artificial inflammation to immune cells. Some of the cells received various doses of polyphenols that had reacted with an amino acid, while others only received polyphenols in the same doses. A control group received nothing.
The researchers observed that immune cells treated with the combination of polyphenols and amino acids were twice as effective at fighting inflammation as the cells to which only polyphenols were added.
“It is interesting to have now observed the anti-inflammatory effect in cell experiments. And obviously, this has only made us more interested in understanding these health effects in greater detail. So, the next step will be to study the effects in animals,” says senior author Andrew Williams of the veterinary and animal sciences department.
Anti-inflammatory coffee and milk
In previous studies, the researchers demonstrated that polyphenols bind to proteins in meat products, milk, and beer. In another new study, they tested whether the molecules also bind to each other in a coffee drink with milk. Indeed, coffee beans are filled with polyphenols, while milk is rich in proteins.
“Our result demonstrates that the reaction between polyphenols and proteins also happens in some of the coffee drinks with milk that we studied. 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,” says Nissen Lund.
Therefore, the researcher does not find it difficult to imagine that the reaction and potentially beneficial anti-inflammatory effect also occur when other foods consisting of proteins and fruits or vegetables are combined.
“I can imagine that something similar happens in, for example, a meat dish with vegetables or a smoothie, if you make sure to add some protein like milk or yogurt,” says Nissen Lund.
Industry and the research community have both taken note of the major advantages of polyphenols. As such, they are working on how to add the right quantities of polyphenols in foods to achieve the best quality. The new research results are promising in this context as well.
“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,” says Nissen Lund. “This strategy has the added advantage of enhancing the anti-inflammatory effects of polyphenols.”
Additional coauthors are from the Technical University of Dresden in Germany. Independent Research Fund Denmark funded the work.
Source: University of Copenhagen