Many people believe drinking more tea is beneficial for health and helps prevent cancer, but if tea is consumed improperly, it may backfire.

First, let's talk about why tea helps prevent cancer. Tea is rich in natural antioxidants such as "tea polyphenols." When consumed before or after meals, these antioxidants work synergistically to eliminate free radicals, enhancing tea's cancer-preventive and anticancer effects.

Green tea contains five times the amount of "tea polyphenols" found in ordinary tea. Green tea can reduce the incidence of certain cancers. The molecular structure of green tea polyphenols is similar to that of the anticancer drug Methotrexate. DHFR is crucial for both healthy and cancer cells, and green tea polyphenols have a strong binding affinity to DHFR, though weaker than Methotrexate, resulting in fewer side effects on healthy cells than the drug.

Case studies from research institutions also show significant anticancer effects of tea:

Foreign researchers surveyed 20 male patients with prostate cancer. They drank five cups of green tea, black tea, or other teas daily before surgery. Post-surgery analysis of their blood samples and prostate tissue revealed higher levels of phenolic compounds. When cancer cell cultures were treated with black tea, green tea, or soda, the growth rate of cancer cells significantly slowed.

Researchers from Curtin University in Australia and Zhejiang Cancer Hospital in China conducted experiments on 900 women to investigate the causes of ovarian cancer. Among them, 254 had been diagnosed with ovarian cancer, while 652 were healthy. The results showed that daily tea consumption, especially green tea, significantly reduced the incidence of ovarian cancer in women.

A research team led by Judy Rees at the Dartmouth Medical School in New Hampshire, USA, studied the dietary habits and health status of 2,200 adults. They found that tea drinkers had a lower risk of developing two common skin cancers: squamous cell carcinoma and basal cell carcinoma. Those who drank more than one cup of tea daily had a 20% to 30% lower risk of developing these cancers compared to non-tea drinkers.

However, it is also important to use the correct method of drinking tea; otherwise, it may increase the risk of cancer.

1. The water temperature for brewing tea should not be too high. Iranian researchers published a study indicating that drinking a cup of hot tea daily increases the risk of esophageal cancer. Moreover, when the tea water temperature is between 65°C and 69°C, the risk of esophageal cancer doubles. Once the water temperature exceeds 70°C, the risk increases by 8 times. If tea is consumed within 2 minutes of being poured, the risk of esophageal cancer rises about 5 times compared to waiting 4 minutes. Another study found that a tea water temperature between 56°C and 60°C is more beneficial for health.

2. If the purchased tea contains pesticides, it can also be harmful to health. There are two ways to avoid this:

(1) Choose trustworthy brands that produce pre-Qingming tea. Since the weather is cold before Qingming Festival, no pesticides are needed to eliminate pests, so there is no concern about pesticide residues in the tea.

(2) After purchasing post-Qingming tea, pour out the first infusion when brewing. When steeping the tea, keep the lid open and do not trap the steam, as some pesticide substances may evaporate with the steam.