Starches and sugars are two well-known components in the development of obesity and type 2 diabetes. However, it is less known how the small chemical compounds flavonoids, which are found in nearly all fruits and vegetables, and which are famous antioxidants, contribute to protect us from the negative effect of sugars.

Mario M. Martinez from Aarhus University will explore this in a new research project.

He has just been awarded the prestigious Sapere Aude research grant of 6.2 million DKK, which is awarded to some of Denmark's most promising research leader talents by the Independent Research Fund Denmark.

- Too many people miss out on too many years of quality of life due to diseases related to a high blood sugar. We cannot reverse this problem by removing carbohydrates from the diet because we need them for basic metabolic functions, and neither can we rely heavily on will power since this would benefit only those with the time, money and cognitive and psychological resources to follow a strict diet. Therefore, solutions, which are accessible to everybody, are urgently needed. Understanding the complexities in flavonoid bioavailability and metabolism could be promising for metabolic health, he says.

Solving the mystery of cell wall bindings

Existing studies of flavonoids have shown a positive impact on insulin sensitivity and other factors related to the development of obesity and type 2 diabetes, but they have mostly focused on pure flavonoids, which are extracted from fruits and vegetables and refined - and that is not how we find them in our food.

In reality, the flavonoids will participate in complex interactions with polysaccharides, including those from the plant cell wall, during processing in different ways - either in the food industry or during our digestion, for example by heating or chewing.

These interactions could critically affect the stability and functionality of flavonoids, most of which are sensitive to high temperature and will partially or completely degrade during cooking.

- However, it is unclear what happens in these processes. Are flavonoids released from the plant cell wall? Where? Could we tailor these interactions to decide where flavonoids can be delivered in our body? This research will try to answer some of these questions, Mario M.  Martinez says and adds: 

- We need to understand how the different flavonoids are bound to the different polysaccharides, if we want to change the way our body utilizes sugars and starches through the action of flavonoids.

Once these mechanisms are clear, the research project will investigate the potential role played by flavonoids in, for example regulating blood sugar levels, and improving glycemic and obesity control through the enhancement of the gut microbiome. More particularly, different specific locations in our body will be studied to find out how they react to bound flavonoids in order to protect us against sugars.

Using byproducts for sustainable solutions

If the project succeeds in demonstrating a significant effect of bound flavonoids, this might subsequently stimulate industry to upcycle side streams with a potential to also contribute to a more sustainable food production system.

- Plenty of fruits and vegetables never reach our plates, but technology development has the potential to upcycle them and avoid their waste.  We know, for example, that pomace from wine production contains flavonoids. It could be fantastic, if we could utilize this and recognize this side stream for the gold it is, Mario M. Martinez concludes.