China is the birthplace of tea, and the habit of drinking tea among its people dates back thousands of years, with virtually every household keeping a selection of teas on hand. Tea, one of the most popular daily beverages, serves more than just to quench thirst. Modern pharmacological studies have shown that tea is rich in various medicinal components, such as tea polyphenols, tea polysaccharides, alkaloids, vitamins, and so forth, which offer excellent health benefits to the human body. This is especially true for those suffering from the three highs (high blood pressure, high cholesterol, high blood sugar) and Cardiovascular diseases, who can experience surprising benefits from long-term tea consumption.
Drinking More Tea Helps Control the Three Highs and Protects Blood Vessels
1. Catechins Can Help Lower Blood Pressure
The American College of Cardiology compiled 21 valid studies involving 1,323 participants and found that compared to non-tea drinkers, tea drinkers had an average systolic blood pressure reduction of 1.8 mmHg and a diastolic blood pressure reduction of 1.4 mmHg. The blood pressure-lowering effects were even more pronounced after 12 weeks of tea consumption. The secret lies in the antioxidant catechins contained within tea, which open protein channels on the membranes of vascular smooth muscle cells, accelerating the absorption of potassium ions. This leads to the relaxation and expansion of blood vessels, thereby lowering blood pressure. Furthermore, when green tea is heated to around 35°C, its blood pressure-lowering effects are at their best. Therefore, it's advisable to wait until the tea cools down to a temperature similar to that of the body before drinking it, thus avoiding burns caused by hot tea.
2. It Can Help with Weight Loss and Lipid Reduction
In the Tang Dynasty, “The Supplement to the Materia medica” mentioned that “long-term consumption makes one slimmer.” Modern scientific research confirms this observation. The caffeine in tea promotes gastric juice secretion, aiding digestion and enhancing the body's ability to break down fat. Researchers at Zhejiang University's Tea Research Institute discovered that epigallocatechin gallate (EGCG), a complex catechin in tea, can increase thermogenesis in brown fat, helping to consume excess energy and aid in weight loss. Additionally, EGCG can inhibit microglial cells, reducing hypothalamic inflammation, which improves body weight and regulates the normal function of the central nervous system.
3. Tea Polysaccharides Can Help Control Blood Sugar
An animal experiment conducted by the Zhejiang Academy of Medical Sciences found that tea polysaccharides significantly alleviate the “three more and one less” symptoms (frequent urination, increased thirst, increased appetite, and weight loss) associated with diabetes, aiding in the reduction of fasting blood glucose levels. Researchers at Zhejiang University School of Medicine also discovered that tea polysaccharides can enhance the body's antioxidant capacity, protecting pancreatic β-cells from oxidative damage, thereby preventing diabetes. Moreover, tea polysaccharides can enhance the activity of hepatic glucokinase, acting similarly to Insulin, improving sugar metabolism and aiding in the reduction of blood sugar levels. Additionally, polysaccharides have a unique adhesive property that allows for the gradual release of carbohydrates in the gut, contributing to blood sugar control and reduction of blood sugar peaks. A study by Huazhong Agricultural University found that green tea contains the highest amount of tea polysaccharides, followed by Oolong and black tea.
4. Reduces the Risk of Cardiovascular Diseases
A study published in the Journal of the American Heart Association, which followed over 80,000 Chinese individuals for six years, analyzed the relationship between changes in high-density lipoprotein cholesterol levels and tea consumption. The results showed that those who consistently drank tea had a slower decline in high-density lipoprotein cholesterol (good cholesterol) levels, reducing the risk of cardiovascular disease by 8%. Furthermore, the study indicated that green tea had the strongest effect, followed by black tea, and weakest in herbal teas. In addition to drinking green tea, black tea, and Flower tea directly, adding some traditional Chinese medicines can enhance the disease prevention and resistance capabilities.
Points to Note When Drinking Tea
All things have two sides, and while tea is beneficial, it contains substances like tannic acid, alkaloids, and tannins, so it should not be consumed indiscriminately. Here are some points to keep in mind:
1. Drink Light Tea in Moderation
As the saying goes, “Light tea drunk warm is most nourishing.” Strong tea refers to tea made with excessive amounts of leaves or steeped for too long, resulting in a bitter and astringent taste. Strong tea contains higher levels of fluoride, which can harm the kidneys. Long-term consumption can irritate the stomach lining, increasing the risk of gastric diseases and even gastric cancer. The tannic acid in strong tea can reduce intestinal fluid secretion, leading to constipation. Therefore, it is appropriate for healthy adults to consume about 12 grams of tea per day, using 3 grams of tea leaves for each 150 milliliters of water.
2. Avoid Drinking Tea Upon Waking or Before Bed
Drinking tea on an empty stomach in the morning dilutes gastric juices, weakening digestive function. Tea has stimulating and diuretic effects, which can affect sleep quality if consumed before bedtime. It is recommended to drink tea around ten in the morning. The alkaloids in tea can suppress gastric juice secretion, making it unadvisable to drink tea before meals to ensure proper digestion and absorption. Drinking tea immediately after eating can impact the body's absorption of proteins and iron due to the presence of tannic acid in tea. Therefore, it is suggested to drink tea one hour after a meal.
3. Do Not Take Medications with Tea
Tea contains multiple nutrients, some of which can chemically react with medications, affecting their efficacy. Therefore, it is not advisable to take medication with tea.
4. Do Not Drink Overnight Tea
Overnight tea provides proteins, sugars, and other nutrients that can become a breeding ground for bacteria and mold. The tea may spoil easily, losing its aroma and flavor. Drinking overnight tea loses the health benefits of tea and could potentially increase the risk of illness.
5. Unsuitable Populations for Tea Consumption
Individuals suffering from nervous exhaustion, insomnia, hyperthyroidism, tuberculosis, heart disease, gastric diseases, and peptic ulcers are unsuitable for drinking tea, particularly strong tea. Additionally, nursing mothers, pregnant women, and infants should also avoid tea consumption.