Black tea against diabetes? How it may protect health

Introduction

Everyone agrees that tea is healthy. It is now also known that dark tea—in other words, black tea—may be particularly useful for preventing diabetes and easing existing diabetes. This effect, which resembles that of diabetes medication, was presented at the European Association for the Study of Diabetes (EASD) congress in Hamburg.

Contents

1. Black tea and green tea: what’s the difference?
2. Black tea may protect against diabetes
3. Conclusion: black tea and diabetes

1. Black tea and green tea: what’s the difference?

Whether green, yellow or red tea, matcha or black tea, they all come from the same species: Camellia sinensis, also known as the tea plant. 

The main difference is how the leaves are processed. Green tea is dried as soon as possible after harvesting. Black tea, associated with particularly beneficial properties in relation to diabetes, is fermented for a while before drying. 

2. Black tea may protect against diabetes

Fermentation, which also involves oxidation of the leaves, changes their chemical composition. Black tea does not necessarily have fewer antioxidants than green tea, but it contains different ones.

Microbial fermentation produces bioactive compounds such as alkaloids, free amino acids, polyphenols and polysaccharides, which the study says are responsible for black tea’s effects against diabetes.

Among the 2,000 participants in the study, researchers found a 53% lower risk of prediabetes and a 47% lower risk of type 2 diabetes.

The study’s professors, Prof. Zilin Sun and Prof. Tongzhi Wu, say black tea promotes glucose excretion in urine and improves insulin resistance and blood glucose control.

The potent antioxidants in black tea strengthen the pancreas, increasing insulin production while also improving insulin sensitivity.

Microbial fermentation is also said to improve gut flora, which may contribute to better overall health.

3. Conclusion: black tea and diabetes

If a cup of black tea a day significantly reduces the risk of developing diabetes—and even makes insulin use easier for people who already have it—there seems little reason not to have that extra cup.

When processing our green Guayusa tea PURE into Guayusa DARK, we took inspiration from the fermentation that turns green tea into black tea. That is why our Guayusa DARK should have this effect too.

The main difference, of course, is the overall flavour. Black tea has many bitter compounds, while Guayusa tastes mild and even slightly sweet.