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.
- Polyphenols are a group of naturally occurring antioxidants important for humans.
- They prevent and delay the oxidation of healthy chemical substances and organs in our bodies, thereby protecting them from damage or destruction.
- Polyphenols are found in a variety of fruits and vegetables, tea, coffee, red wine and beer.
- Due to their antioxidant properties, polyphenols are used in the food industry to minimize the oxidation of fats in particular, as well as the quality deterioration of foods, to avoid off flavors and rancidity.
Twice as good at fighting inflammation
Professor Marianne Nissen Lund from the Department of Food Science and his team did a study that showed 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.
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.
Found in coffee with milk
Previous studies by 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.
The results demonstrate 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 any of the foods that they´ve studied so far.
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
Jingyuan Liu, Mahesha M. Poojary, Ling Zhu, Andrew R. Williams, Marianne N. Lund. Phenolic Acid–Amino Acid Adducts Exert Distinct Immunomodulatory Effects in Macrophages Compared to Parent Phenolic Acids. Journal of Agricultural and Food Chemistry, January 30, 2023; DOI: 10.1021/acs.jafc.2c06658
Mahesha M. Poojary, Michael Hellwig, Thomas Henle, Marianne N. Lund. Covalent bonding between polyphenols and proteins: Synthesis of caffeic acid-cysteine and chlorogenic acid-cysteine adducts and their quantification in dairy beverages. Food Chemistry, September 22, 2023; 403: 134406 DOI: 10.1016/j.foodchem.2022.134406
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