Our immune systems deploy white blood cells and chemical chemicals to defend us if bacteria, viruses, or other foreign things enter the body. This response, known as inflammation, is typical of conditions like rheumatoid arthritis and also happens anytime we stress tendons and muscles.

Polyphenols are antioxidants found in people, plants, fruits, and vegetables. The food industry makes use of this class of antioxidants to keep foods from being rancid or going off taste before their time. Polyphenols are recognized to be beneficial to human health due to the fact that they help minimize the oxidative stress that occurs inside the body and is the root cause of inflammation.

Still, there is a lot about polyphenols that we don’t know. Not many studies have looked into what happens when polyphenols interact with other molecules, like proteins in foods we eat.

In a new study, researchers from the University of Copenhagen’s Department of Food Science and Department of Veterinary and Animal Sciences looked at how polyphenols act when mixed with amino acids, which are the building blocks of proteins. The outcomes have been encouraging.

“In the study,” as explained by lead author Prof. Marianne Nissen, “we show that as a polyphenol reacts with an amino acid, its inhibitory effect on inflammation in immune cells is enhanced. 

“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.”

The findings were published in the Journal of Agricultural and Food Chemistry today.

Two times as effective in reducing inflammation

To examine the anti-inflammatory impact of mixing polyphenols with proteins, researchers subjected immune cells to artificial inflammation. While some cells just got polyphenols in the same amounts, other cells received different dosages of polyphenols that had interacted with an amino acid. A control group was not given anything.

The researchers found that adding polyphenols and amino acids to immune cells doubled their ability to reduce inflammation compared to cells that simply received polyphenols.

“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,” adds senior author Andrew Williams.

Coffee mixed with Milk

The researchers have shown in previous experiments that polyphenols bond to proteins and those proteins may be found in meat products, milk, and beer.

In a different recently published study, the researchers investigated whether or not the molecules connect to one another in a coffee drink that also included milk.

Indeed, milk is a great source of proteins, while coffee beans are full of polyphenols.

“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,” adds Marianne Nissen Lund.

So, it’s not hard for the researcher to believe that the reaction and possibly helpful anti-inflammatory effect could also happen when other foods with 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,” adds Marianne Nissen Lund.

Polyphenols’ benefits are recognized by industry and research. So, they are trying to figure out how to add the right amount of polyphenols to foods to make them the best. In this case, too, the new research results look good:

“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. This strategy has the added advantage of enhancing the anti-inflammatory effects of polyphenols,” points out Marianne Nissen Lund.

About Polyphenol

• Polyphenols are an important class of antioxidants found in nature.
• They stop and slow the oxidation of healthy chemicals and organs in our bodies, which keeps them from being hurt or destroyed.
• Numerous fruits and vegetables, tea, coffee, red wine, and beer all contain polyphenols.
• Polyphenols are utilized in the food industry to prevent off flavors and rancidity by reducing oxidation of lipids in particular as well as the quality degradation of foods.

Source: 10.1021/acs.jafc.2c06658

Image Credit: Getty