Tea and its Influence on Blood Sugar Levels

Tea is a popular beverage in many cultures around the world. It is made from the leaves of the Camellia sinensis plant, an evergreen shrub which is cultivated in many countries around the world.

People drink tea for various reasons, including its calming effects, health benefits, and as a means of socialising. In Ghana, although often enjoyed as a breakfast beverage, teas are generally emerging as a popular choice due to potential health benefits.

As more people turn to tea for wellness, its effects on various health markers, including blood sugar levels, are becoming more relevant. This article highlights how some selected teas (green, black and herbal teas), can influence blood sugar levels.

Teas are classified into several types based on how the leaves are processed. The most commonly consumed types are black, green, white, and oolong tea. Herbal teas or infusions, which are technically not teas from the Camellia sinensis plant, include varieties like cinnamon, hibiscus, and chamomile.

All true teas contain active compounds such as catechins, polyphenols, and flavonoids, which have been shown to provide numerous health benefits. These compounds possess antioxidant and anti-inflammatory properties, which can improve overall metabolic health and help regulate blood glucose by improving insulin sensitivity and slowing the absorption of glucose in the gut.

Catechins, specifically, are believed to protect pancreatic beta cells from damage, potentially helping to regulate insulin production and secretion.

Green Tea and Blood Sugar Control

Green tea, often praised for its health benefits, has a unique profile of catechins, especially Epigallocatechin gallate (EGCG), a powerful catechin with antioxidant properties, which plays a critical role in managing blood sugar.

Studies show that green tea can improve glucose metabolism by increasing insulin sensitivity and lowering fasting blood glucose levels. One such study published in the American Journal of Clinical Nutrition found that individuals who drank green tea regularly had a lower risk of type 2 diabetes.

Black Tea and Blood Sugar Control

Black tea, which undergoes full fermentation, contains polyphenols (e.g. theaflavins and thearubigins), in addition to catechins. These compounds have been studied for their impact on metabolic health. While black tea shares some similarities with green tea, studies suggest it may be slightly less effective in reducing blood glucose levels.

However, it still plays a valuable role in regulating insulin. One study found that black tea polyphenols may reduce blood sugar spikes after eating by inhibiting, an enzyme (alpha-glucosidase) that breaks down starches into glucose.

Other Teas and Blood Sugar

In addition to black and green teas, several other teas may influence blood sugar levels. Herbal teas like cinnamon, hibiscus, peppermint and chamomile, which do not contain actual tea leaves, also show promise.

Chamomile tea has been linked to reduced blood sugar levels and improved glycated hemoglobin (HbA1c) levels in individuals with diabetes. Cinnamon has been shown to enhance insulin sensitivity and lower blood sugar levels through various mechanisms, including slowing carbohydrate absorption.

Peppermint tea may also have mild effects on insulin function, though its impact is less studied. Though much of the evidence is primarily anecdotal, many people find herbal teas to be helpful as part of a natural blood sugar management strategy.

Several factors can influence the effects of teas on blood sugar levels. For instance, adding sugar or sweetened syrups to tea can counteract the beneficial effects on blood sugar regulation. Also adding milk to teas can alter the antioxidant properties of the tea, although the extent of this effect can vary widely among teas. Thus, for maximum antioxidant benefits, you might prefer to drink your tea without milk.

To conclude, antioxidants and active compounds found in teas can improve insulin sensitivity and support healthy glucose metabolism. By mindfully incorporating a variety of teas into a balanced diet that is rich in whole grains, vegetables, lean proteins, and healthy fats, individuals can derive meaningful health benefits. A registered dietitian can offer personalized recommendations based on the individual's health profile.

References

Jing, J., & Zhou, S. (2020). Effects of green tea on glucose control and insulin sensitivity: A meta-analysis. American Journal of Clinical Nutrition, 112(5), 1-9.

Mozaffari-Khosravi, H., Ahadi, Z., & Barzegar, K. (2014). The effect of chamomile tea consumption on glycemic control and serum lipid profile in patients with type 2 diabetes. Journal of Endocrinological Investigation, 37(10), 971-976.

Striegel, L., Kang, B., Pilkenton, S. J., Rychlik, M., & Apostolidis, E. (2015). Effect of Black Tea and Black Tea Pomace Polyphenols on α-Glucosidase and α-Amylase Inhibition, Relevant to Type 2 Diabetes Prevention. Frontiers in nutrition, 2, 3. https://doi.org/10.3389/fnut.2015.00003

Written by Pearl Kudexa (MSc,RD) and Laurene Boateng (PhD, RD)

Pearl Kudexa (MSc, RD) is a Registered Dietitian and contributing writer for www.fullproofnutrition.com

Laurene Boateng (PhD, RD) is a Registered Dietitian and Senior Lecturer in the Department of Dietetics, University of Ghana. She is the founder and editor-in-chief of www.fullproofnutrition.com , a website committed to providing reliable, evidence-based, and practical healthy eating advice.

Consulting a registered dietitian empowers you to take control of your health and make informed dietary choices that support your well-being.

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