After water, tea is the most widely consumed beverage in the world. In China, it’s considered the national drink, with many enthusiasts so devoted they’d “rather go a day without food than a day without tea.” Especially in the summer, tea is a refreshing way to cool down and aid digestion after a meal.
So, what are the specific health benefits of a daily tea habit? Let’s delve into the science.
What Are the Health Benefits of Drinking Tea?
1. Lowers the Risk of Type 2 Diabetes
Two major meta-analyses, encompassing a total of 22 and 17 Randomized Controlled Trials (RCTs) respectively and involving nearly 50,000 participants, reached a consensus: for individuals at high risk of diabetes, tea consumption helps control blood sugar and improve insulin sensitivity. For those already diagnosed with diabetes, drinking tea is beneficial for lowering fasting blood glucose and glycated hemoglobin (HbA1c) concentrations.
Furthermore, these health benefits appear consistent across different ethnic groups. A study that followed 38,000 middle-aged and older women (≥45 years) in the United States for an average of 8.8 years found that women who drank ≥4 cups of tea per day had a 30% lower risk of developing type 2 diabetes compared to non-tea drinkers.
Similarly, a study of 480,000 adults in China over 11 years revealed that daily tea drinkers had an 8% lower risk of type 2 diabetes compared to participants who had not consumed tea in the past year.
2. Reduces Stroke Risk
A study following 82,369 Japanese men and women for an average of 13 years showed that those who drank 2-3 cups of green tea daily had a 14% lower risk of stroke, while those consuming 4 or more cups had a 20% lower risk.
The ability of green tea to reduce stroke risk is primarily attributed to its catechins, which protect blood vessels through various mechanisms, including antioxidant, anti-inflammatory, anti-proliferative, and anti-thrombotic effects.
3. Lowers the Risk of High Blood Pressure
Research on 76,000 adults in China indicated that drinking tea can lower the risk of hypertension, with green tea specifically reducing the risk by 6%. Even for those who don’t drink it daily or in large quantities, consistent consumption over the long term can contribute to lowering hypertension risk.
The potential mechanisms are twofold: The catechins abundant in green tea promote the production of nitric oxide, which dilates blood vessels, leading to lower blood pressure. Additionally, catechins can inhibit the production of angiotensin-converting enzyme (ACE). Suppressing this enzyme causes blood vessels to relax and blood volume to decrease, thereby reducing blood pressure.
Drinking black tea was associated with a 26% reduction in hypertension risk. This significant decrease is mainly because black tea lowers both systolic and diastolic blood pressure. The two primary explanations for this are: First, the thearubigins and theaflavins in black tea protect the vascular endothelium from free radical damage, keeping blood vessels smooth and elastic, which helps in vasodilation. Second, various compounds in black tea can function similarly to calcium channel blockers, a class of drugs used to lower blood pressure.
4. Reduces Mortality Risk
A 2022 study published in the Annals of Internal Medicine followed approximately 500,000 tea drinkers aged 40-69 for about 11 years. The findings revealed that individuals who drank ≥2 cups of tea per day had a 9%-13% lower risk of all-cause mortality compared to non-tea drinkers.
How Can You Maximize the Health Benefits of Tea?
If you’re a daily tea drinker, you might be surprised by this extensive list of health benefits! Now, let’s look at how to properly store and drink tea to get the most out of it.
1. Store Tea in a Sealed, Dark, and Cool Place
Tea leaves easily absorb moisture and odors, and theanine—the amino acid responsible for the “fresh and brisk” flavor—can be easily lost. The antioxidant tea polyphenols can also degrade through oxidation, a process that accelerates at higher temperatures. Therefore, it’s essential to store tea in sealed, light-proof containers at a low temperature. For tea you don’t plan to drink soon, you can even vacuum-seal and freeze it.
2. Use the Right Water Temperature for Brewing
It is generally recommended to brew green tea with water around 80°C (176°F), and to use boiling water for black and oolong teas. This approach balances the extraction of compounds like caffeine, tea polyphenols, and theanine, resulting in a better-tasting cup.
3. Let the Tea Cool Before Drinking
The Gongfu tea tradition of the Chaoshan region in China emphasizes drinking tea while it’s scalding hot. However, this is not advisable. Consuming beverages at high temperatures can damage the esophagus and increase the risk of esophageal cancer. The International Agency for Research on Cancer (IARC), a part of the World Health Organization, has classified drinking beverages hotter than 65°C (149°F) as a probable carcinogen. Therefore, it’s best to let tea brewed with boiling water cool to a comfortable temperature before drinking.
4. Drink More Light Tea, Less Strong Tea
Strong tea contains more caffeine, which can lead to issues like nausea, heartburn, and palpitations. Drinking it in the afternoon or evening can also disrupt sleep. Furthermore, the high concentration of tannins in strong tea can interfere with iron absorption, so individuals with iron-deficiency anemia should ideally avoid it.
After reading this, if you already love tea, perhaps you appreciate it even more. And if you weren’t a tea drinker before, maybe now you’re inspired to start.
References
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