Black Tea Helps Manage Blood Sugar (New Study!)


Black Tea For Blood Sugar Management


Although green tea has been getting most of the attention lately for its myriad health benefits, accumulating research shows that black tea offers advantages, too.

The latest revelation: black tea’s ability to blunt increases in blood sugar. 

A new study, published in the Asia Pacific Journal of Clinical Nutrition, has found that black tea significantly reduces rises in blood glucose levels among both healthy and pre-diabetic adults, after consuming a sugary drink.


The authors of the study concluded:


“We demonstrated that black tea reduced incremental blood glucose after sucrose consumption at 60, 90 and 120 minutes compared with placebo.”


“The data confirm that polyphenols lower glycemic response and may be responsible for the lower rates of diabetes observed with tea and coffee consumption,” said Peter Clifton, M.D., PhD., professor of nutrition at the University of South Australia in Adelaide.


Dr. Clifton recently conducted a review of the role of dietary polyphenols (in tea, cinnamon, coffee, chocolate, pomegranate, red wine and olive oil, among others) in regulating glucose homeostasis and insulin sensitivity, published in Nutrients



Diabetes and Pre-Diabetes are Epidemic



Type 2 Diabetes (Diabetes Mellitus Type 2)

Type 2 diabetes is the most common form of diabetes, and occurs when the body doesn’t use insulin properly (insulin resistance).

At first, the pancreas makes extra insulin to make up for it. But over time, your pancreas isn’t able to keep up and can’t make enough insulin to keep your blood glucose levels normal.

It’s treated with lifestyle changes, oral medications, and insulin

When glucose builds up in the blood instead of going into cells, it can cause two problems:

  • Right away, your cells may be starved for energy.
  • Over time, high blood glucose levels can damage your eyes, kidneys, nerves or heart.

Some people with type 2 can control their blood glucose with healthy eating and being active. But your doctor may need to also prescribe oral medications or insulin to help you meet your target blood glucose levels.


Target Blood Glucose Levels


Type 2 usually gets worse over time – even if you don’t need medications at first, you may need them later on.


Type 2 Diabetes Risk Factors

 The exact cause for development of  type 2 diabetes is unknown, although genetics and environmental factors, such as excess weight and inactivity, seem to be contributing factors.




Some groups have a higher risk for developing type 2 diabetes than others; it’s more common in African Americans, Latinos, Native Americans, and Asian Americans/Pacific Islanders, as well as the aged population.



As of 2015, 415 million people in the world—one of 11 adults—have diabetes, according to the Brussels-based International Diabetes Federation.

By 2040, that number is expected to climb to 642 million. An estimated 318 million worldwide have impaired glucose tolerance, or pre-diabetes


The U.S. leads the developed world in diabetes, with more than 29 million cases among adults, according to the Centers for Disease Control and Prevention.


About 86 million adults in the country—more than one-third of the population—have pre-diabetes, a serious health condition that increases the risk of developing type 2 diabetes as well as other chronic diseases.


Unfortunately, the vast majority of those with pre-diabetes (90%) don’t know they have it. 




Black Tea Polyphenols Fight Diabetes



The major bioactive compounds in black tea are polyphenols—naturally occurring antioxidants abundant in plant foods (and drinks) that have been shown to promote health and protect against a range of diseases. 

Black, green and oolong teas are all made from the plant Camellia Sinensis. Green tea, which is minimally oxidized, contains simple flavonoids called catechins.

During the process of making black tea, which is more fully oxidized, the catechins convert to complex flavonoids known as theaflavins and thearubigens, and research has shown that theaflavins and thearubigens maintain substantial anti-oxidant, anti-inflammatory, anti-cancer and anti-hypertensive properties.



Ariel Beresniak, M.D., PhD., chief executive officer of Data Mining International in Geneva and lead author of a large global study on black tea and health published in the British Medical Journal stated:


“The new study confirms the findings of a number of biological, physiological, clinical, epidemiological and ecological studies suggesting a positive effect of black tea consumption on diabetes prevention and clinical diabetes.”


The study, which involved data from 50 countries around the world, found that countries with the highest levels of black tea consumption—Ireland followed by the United Kingdom, Turkey and Russia—were associated with the lowest incidence of type 2 diabetes.

The U.S. ranked close to the bottom of the list of black-tea drinking countries


Countries with the highest levels of black tea consumption are associated with the lowest incidence of type 2 diabetes.


Future Research

Still, the new study doesn’t prove cause and effect, Dr. Beresniak said, adding that more causality research needs to be done on the glucose-control benefits of black tea. 

While black tea extracts have been shown in laboratory experiments to block carbohydrate absorption and to suppress postprandial blood glucose in animal studies, the authors of the latest report said they undertook their study because of the vast amount of clinical research on the effects of black tea on postprandial (after-meal) glycemic control in humans.

The authors also noted that keeping blood sugar in check after meals is a critical but simple way to help prevent diabetes, and that black tea, regarded as a functional food, may be useful to that end. 


How to Brew Black Tea

(For Maximum Health Benefits and Flavor!)



As a general rule of thumb, use 2 to 3 grams of tea leaves per 6 ounces of water. Measuring by weight is preferable because tea leaves come in different sizes. If you want to measure by volume, start with 1 rounded teaspoon.

For larger leaf sizes, you may want to use up to 1 or 2 tablespoons. Again, experiment to see what works for you.


The Water

The water you use is perhaps just as important as the tea leaves. Whether it’s tap, filtered, or spring water, it should taste good.

Avoid distilled water, which can taste flat. Start with fresh, cold water that has not been previously boiled.

As a general rule of thumb, let the water come just to a rolling boil. Depending on which expert you consult, the ideal temperature can range from 190° to 212°F, which you can measure using a thermometer, or simply eyeball it.

Heating the water to the optimal temperature will bring out the right balance of tannins. If the water temperature is too low, it may not extract the full range of flavors. If the temperature is too high, the tea will be too tannic and taste bitter.


Steeping Time

As a general rule of thumb, steep the tea from 3 to 5 minutes. The exact amount of time will depend on the particular tea leaves, the cut of the leaves, and your personal preference for a stronger or milder brew.

You may wish to taste the tea at the 3-minute mark and then every 30 seconds to discover your sweet spot. Take notes for future reference.

Tip: To make a strong tea, use more tea leaves rather than more time, which will make the tea bitter.


Infusers and Strainers

Keep in mind that you want room for the tea leaves to unfold and release their flavors.


Tea leaves can expand 3 to 5 times in size.


For this reason, a roomier basket-style infuser or filter (made of glass, metal, or cloth) is usually preferable to the ball-style of infuser.

I have this Tea Infuser Set from Chefast, and if you don’t have an infuser yet, I recommend it.  The set includes three stainless steel steepers and a multi-functional scoop/bag clip (I find it’s an excellent value for the quality). 


Chefast Tea Infuser Set


You can also brew the tea leaves directly in the pot or cup and strain them out as you pour.


Step-by-Step Black Tea Recipe

Makes 1 cup (multiply as desired)


What You Need

6 ounces water, plus more if pre-warming the pot or cup
2 to 3 grams or 1 rounded teaspoon loose leaf black tea
Optional: milk, lemon, sugar, honey, fruit preserves (Russian tradition)

Kettle to boil water
Thermometer (optional)
Scale or measuring spoon
Filter or strainer
Tea cup for serving
Spoon for stirring milk, sweetener, lemon (optional)



  1. Heat the water. Place the water in a tea kettle and heat it just to a rolling boil, or between 200° and 212°F.
  2. Pre-warm the teapot or cup (optional). Pour a small amount of boiling water into the pot or cup. When the pot or cup is warm, pour out the water.
  3. Measure the tea leaves. Using a scale, measure 2 to 3 grams of tea leaves. Alternatively, measure 1 rounded teaspoon of tea leaves.
  4. Place the leaves in the teapot or cup. Place the tea leaves in the pot or cup, either directly or in an infuser.
  5. Pour the water. Pour the water over the tea leaves.
  6. Cover the teapot or cup. Place the lid on the teapot or, if using a cup, cover it with a lid or a small saucer.
  7. Keep it cozy (optional). Cover the teapot or cup with a tea cozy or a thick towel to retain heat.
  8. Steep the tea. Set a timer for 3 to 5 minutes. You may wish to taste the tea at 3 minutes and then every 30 seconds until it is to your liking.
  9. Stop the infusion. As soon as the tea is ready, remove the leaves by lifting out the infuser or pouring the tea through a strainer.
  10. Add milk, lemon, or sweetener (optional). If using milk, heat it gradually by adding the milk to the cup first, then pouring in the tea. Avoid combining milk and lemon, or the milk may curdle.


You can flavor your black tea by adding milk or lemon, and a sweeter.


Recipe Notes

  • Reusing tea leaves. Whole tea leaves can often be steeped 2 to 3 times. Increase the steep time with each infusion.


Video:  How to Make Good Black Tea

Expert Joey Papa demonstrates how to make a single serving of black tea using a tea press (French press).



This Angelica Stainless Steel and Glass French Press can be used for tea, coffee, and even organic juice.

It’s a gorgeous 34 ounce press with a modern design, combining metal and borosilicate glass.  A bonus scoop is included.

Angelica French Press


How to Store Tea

Avoiding just five storage conditions will make a huge difference in the shelf life of your tea. These factors are light, heat, moisture, odor and air.


  • Store far away from anything with a strong odor.
  • Store in a dark cabinet or completely opaque container.
  • Keep delicate teas separate from strongly scented teas.
  • Avoid storing tea in humid areas of your kitchen and house.


Tea Storage Materials

  • Use opaque packaging if possible.
  • Be sure your packaging is food safe. (For example, don’t use a pencil case to hold tea.)
  • Glazed ceramics, non-reactive metals and opaque, non-leaching plastics all make great packaging materials.
  • Wood packaging may be a workable option, but be aware that many wood containers have odors that can influence the tea’s taste.
  • The bags that suppliers sell tea in vary widely in terms of quality. For long-term storage, make sure your bags are multi-ply with an inner layer of foil or glassine (a substance similar to wax paper). This avoids contamination by water, air or grease.

Note: Plastic ‘sandwich bags’ are not a good storage option, as they expose your tea to light, odor and air.


Tea Storage Mechanisms

A tight seal is key. If the mechanism can hold water, it can protect tea. Good options include:

  • Double lids (these are common with metal tea canisters)
  • Odor-free silicone seals (also common with metal canisters)
For example, this Typhoon Living Tea Canister is made from carbon steel, and has a bamboo lid lined with an airtight silicone seal.
Typhoon Living Tea Canister


Other Storage Tips

  • If your vendor doesn’t use adequate packaging for your tea, resist the urge to continue storing it poorly. Invest in quality packaging and your tea will thank you.
  • Buy fresh tea in small quantities. If you live in an area where good tea is hard to find, ask your favorite vendors if they offer shipping.
  • Only open what you can drink in the next few months. Unless they are well-stored aged pu-erhs or aged oolongs, don’t hold onto teas for years. Instead, drink them when they are at their freshest and best.


Recommended Black Teas


Vahdam Teas


I love and recommend Vahdam black teas (from Amazon).

Vahdam teas are shipped to Amazon’s U.S. warehouses directly from the source in India (they don’t travel in containers for months before eventually being packaged and sold by a distributor).  They also have outstanding customer reviews.

Feel good fact: Vahdam donates 1% of their revenue toward the education of their tea workers’ children in India.

I also recommend Teabox loose leaf black teas.  They buy the first pick of every season and take utmost care when it comes to storage and packaging.

They also work directly with tea growers who know to hand-select tea leaves for their texture, color, scent, and purity.  I’ve never been disappointed with a Teabox purchase.

My personal favorite is the Namsang Classic Summer Black Tea.

Namsang Classic Summer Black Tea


Namsang is a lively cup of tea! It features malty flavors and a brisk character, but sweet notes of dates and wood also provide some mellowness. There’s also interesting tinge of red berries, giving the cup an exotic color.

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