Tea is an important part of the Chinese diet. Research indicates that tea leaves are rich in antioxidants and anti-aging substances. In recent years, increasing studies have shown that drinking tea also benefits cardiovascular health. According to a recent report by the British "Daily Mail," a new study found that drinking three cups of tea daily can significantly reduce the risk of heart attacks by up to 70%.

Similarly, a Finnish study suggested that men who drink more than two cups of tea per day have a 21% lower risk of stroke. French research also found that women who consume more than three cups of tea daily experience a 32% reduction in thrombosis risk. Researchers point out that these benefits are largely attributed to the abundant flavonoids in tea, which have anti-inflammatory, anti-infective, anti-thrombotic, and vascular function-enhancing properties. Which tea is the most effective for "heart protection"? Among commonly consumed teas, green tea offers the best heart protection, followed by Anhua black tea.

However, tea is not suitable for everyone, as it can interfere with the absorption of minerals like iron, calcium, and zinc. Individuals with anemia, children, and pregnant women should avoid it. Among all teas, green tea has the least impact on nutrient absorption, making it the recommended choice, with about three cups per day being ideal. Additionally, tea contains caffeine, which can cause excitement and elevated blood pressure, so those with hypertension should avoid excessive or strong tea. Beginners should follow the principle of "moderation and consistency," starting gradually with small amounts and maintaining the habit long-term for optimal results. Generally, it is not advisable to drink green tea at night due to its higher caffeine content, which may affect sleep. Instead, fermented Anhua black tea is a better option.

Introducing Black Tea

Black tea (dark tea), named for its dark appearance, is one of the six major tea categories and is a post-fermented tea. Its main production areas include Sichuan, Yunnan, Hubei, Hunan, Shaanxi, and Anhui. Black tea uses coarser raw materials and is a primary ingredient for compressed teas. The tea-making process typically involves four steps: killing the green, rolling, pile-fermentation, and drying. Black tea is categorized by region, including Anhui Guiyi black tea (An tea), Hunan black tea (Fu tea), Sichuan Tibetan tea (border tea), Yunnan black tea (Pu'er tea), Guangxi Liubao tea, Hubei old black tea, and Shaanxi black tea (Fu tea).

Origins of Black Tea's Heart-Protective Claims

Nutritional Benefits

Black tea contains abundant nutrients, primarily vitamins and minerals, along with proteins, amino acids, and carbohydrates. For residents in northwestern regions whose diets lack vegetables and fruits but consist mainly of beef, lamb, and cheese, long-term consumption of Hunan black tea serves as a vital source of essential minerals and vitamins, earning it the title of "life tea."

Digestive Aid and Grease Reduction

The caffeine, vitamins, amino acids, and phospholipids in black tea aid digestion and regulate fat metabolism. Caffeine stimulates gastric acid secretion, enhancing appetite and digestion. Japanese studies have scientifically proven that black tea has strong grease-cutting and digestive benefits, explaining its popularity among meat-eating cultures. Additionally, black tea improves gut microbiota and promotes intestinal health. Traditional Chinese remedies use aged black tea to treat bloating, dysentery, and indigestion.

Lipid Reduction and Weight Loss

High blood lipid levels can lead to arterial plaque and thrombosis. Black tea effectively degrades fats, prevents blood clotting, and dissolves fibrinogen. It also inhibits platelet aggregation, relaxes blood vessels, and increases vascular diameter, thereby preventing atherosclerosis in the aorta and coronary arteries. This helps lower blood pressure, soften blood vessels, and prevent cardiovascular diseases.

The tea polysaccharides in black tea are abundant and reduce blood lipids and peroxide activity. A 1990-1991 study by the Chinese PLA General Hospital observed 55 elderly patients with hyperlipidemia who consumed black tea for 180 days (3 grams daily). Among them, 50 showed significant reductions in blood lipids and peroxide activity.

Antioxidant Properties

The free radical theory of aging suggests that under normal conditions, the body balances free radical production and clearance. Black tea is rich in antioxidants like catechins, tea pigments, flavonoids, vitamins C and E, and D-carotene, as well as trace elements like zinc, manganese, copper (components of SOD), and selenium (components of GSHPX). Catechins, theaflavins, theanine, and tea polysaccharides in black tea, especially complex flavonoids, scavenge free radicals, offering antioxidant and anti-aging effects.

Anti-Cancer

Cancer is one of the leading causes of death worldwide.

Since the late 1970s, scientists have discovered that tea or its extracts inhibit various cancers. Hunan Agricultural University used high-throughput screening to demonstrate black tea's significant inhibitory effects on tumor cells (SGC7901 model).

Blood Pressure Reduction

Black tea's blood pressure-lowering effects have long been reported. Japanese studies found that theanine in tea inhibits blood pressure by activating dopaminergic neurons. Caffeine and catechins relax blood vessels, increasing diameter and lowering pressure. Chinese researcher Lou Fuqing discovered that tea pigments prevent clotting, promote fibrinolysis, inhibit platelet aggregation, and reduce triglycerides and LDL while increasing HDL. They also inhibit ACE enzymes, contributing to blood pressure reduction.

Blood Sugar Reduction

Tea polysaccharides in black tea are key to lowering blood sugar. These complex compounds vary widely in composition. Among tested teas, black tea has the highest polysaccharide content and activity, likely due to shorter sugar and peptide chains formed during fermentation, which are more easily absorbed and bioactive.

Antibacterial and Anti-Inflammatory

Theaflavins and thearubigins, the main components of black tea's color, are potent free radical scavengers and antioxidants. Theaflavins also inhibit bacteria like Clostridium botulinum, Enterobacteriaceae, and Staphylococcus aureus, as well as viruses like influenza and rotavirus.

Diuretic and Detoxifying

Caffeine in black tea promotes diuresis by increasing kidney filtration. It also stimulates the bladder, aiding in sobering up. Tea polyphenols precipitate nicotine and eliminate free radicals from smoke, reducing harm. They also adsorb heavy metals, mitigating toxicity.

Precautions

Cold black tea only temporarily cools the body, while hot tea is more effective for heat relief. Hot tea dilates blood vessels, promotes sweating, and reduces body temperature by 2–3°C. Tea's diuretic effect also helps dissipate heat. Polyphenols, pigments, and amino acids in tea stimulate saliva, creating a cooling sensation, which is less pronounced with cold tea.