Introduction
This is a review of a study that was published in the Journal of Agricultural and Food Chemistry, which investigated the health benefits of adding milk to coffee, and the effects it can have on inflammation and the diseases of aging.
Coffee is Great!
Coffee is the most popular beverage in the world, as an avid drinker myself I contribute to the more than 400 billion cups that are consumed each, and every year.
Indeed, more than 450 million cups of coffee are consumed in the United States every single day, so it’s no secret that coffee brings joy to people all over the world.
It can provide a boost in focus, it brings people together, not to mention that it smells and tastes wonderful.
Just Coffee Aroma
Science has shown that just the smell of coffee can make us feel alert, and luckily for coffee fans, there are health benefits, too. Coffee is a source of inflammation-fighting antioxidants and drinking it before exercise has proven fat-burning benefits.
A New Study
Now, a new study proposes that adding a dash of milk that contains protein can boost the health benefits of your cup of coffee. Researchers from the University of Copenhagen in Denmark examined how antioxidants called polyphenols interacted with amino acids, they are the building blocks of proteins, and found that combining them has twice the effect on fighting cellular inflammation as polyphenols alone.
What are Polyphenols?
Polyphenols can be found in many foods, including coffee and tea, fruits, vegetables, red wine, and thankfully even beer.
Like other antioxidants, past studies have shown that some polyphenols can prevent and slow the oxidation of healthy chemicals and protect our bodies from disease.
Polyphenols are thought to do this in part by controlling inflammation, a complex immune response involving cells called macrophages that release several inflammatory mediators.Â
Inflammation helps protect against us infection, but if it isn't controlled properly, it can lead to diseases like type 2 Diabetes, Alzheimer's, and Parkinson's.
Caffeic & Chlorogenic AcidÂ
Caffeic Acid (CA) and Chlorogenic Acid (CGA) are polyphenols that are well known to have strong antioxidant and anti-inflammatory effects.
But the researchers wanted to find out if the reactions that these polyphenols have, with other chemicals, can further affect immune regulation.
Two Adducts
Adducts are products that are made when two or more molecules come together. In this case, the amino acid Cysteine (Cys) that is found in milk products was combined with the Caffeic Acid (CA) and Chlorogenic Acid (GCA), both found in coffee, they were combined to make the adducts CA–Cys and CGA–Cys.Â
To support this research, the authors positively showed, in a previous study, that polyphenols do bind to proteins in coffee that has had milk added to it.
StatementÂ
Professor Marianne Nissen Lund from the University of Copenhagen and co-author of both studies I have referenced said, "Our result demonstrates that the reaction between polyphenols and proteins also happens in some of the coffee drinks with milk that we studied.Â
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."
The Testing
In this study, the researchers used RNA-sequencing to study the immune-regulating effects of CA–Cys and CGA–Cys in macrophage cells subjected to artificial inflammation.Â
Macrophages are a type of white blood cell that play an important role in the human immune system and carry out various functions including engulfing and digesting micro-organisms.Â
They also tested the effects of Caffeic Acid and Chlorogenic Acid in isolation, and then compared them to a control group of macrophages not exposed to the polyphenols or to the Cys adducts.
The Results
As they expected, the polyphenols CA and CGA prevented inflammatory responses. In particular the production of the Reactive Oxygen Species (ROS), prostaglandin E2 (PGE2), and the cytokines Interleukin-6 and Tumor Necrosis Factor (known as TNF).
But when polyphenols CA and CGA were combined with amino acid cysteines found in milk proteins, their anti-inflammatory effects received a considerable boost.
Conflicting Results Â
Macrophage cells exposed to polyphenols on their own showed more than 2.5 times as much Tumor Necrosis Factor activity, as they did in the face of a polyphenol-cysteine adduct.Â
However, there was an exception with the Reactive Oxygen Species, it inexplicably increased in the macrophages when the polyphenol-amino acid combination was present, this was when it was compared to the polyphenol on its own.
StatementÂ
Professor Andrew Williams of the University of Copenhagen and senior author of the study said, "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."
The Future
Obviously further research is needed to figure out why and what these results mean practically for human health.Â
This study only examined how a single type of immune mediator reacts to coffee-like chemicals in a laboratory setting.
Closing StatementÂ
The researchers (Andrew R. Williams, Marianne N. Lund, Jingyuan Liu, Mahesha M. Poojary and Ling Zhu) conclude in their paper that, "Our results can be used as an important reference in applications of adducts formed from phenolic compounds and amino acids in future functional food or medicinal products that aim to modulate metabolic, neurological, or immune-related diseases."
Scientific Links:
https://pubs.acs.org/doi/10.1021/acs.jafc.2c06658
https://pubmed.ncbi.nlm.nih.gov/36715127/
https://www.sciencedirect.com/science/article/abs/pii/S1567576917301595?via%3Dihub
https://rb.gy/0gwn5
https://science.ku.dk/english/press/news/2023/coffee-with-milk-may-have-an-anti-inflammatory-effect/
https://www.sciencedaily.com/releases/2023/01/230130090347.htm
https://onlinelibrary.wiley.com/doi/abs/10.1111/jfbc.14264
https://www.sciencealert.com/coffee-smells-are-enough-to-perk-up-the-brain
https://www.mdpi.com/2072-6643/8/1/16
https://tools.myfooddata.com/protein-calculator/170859/wt4/1
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