For medical professionals only
Three cups of tea a day keeps stomach cancer away from you and me!
In addition to drinking water, the beverage that people drink the most is tea. We may drink green tea, black tea, oolong tea, white tea… According to statistics, in 2020, the global consumption of tea will reach 6.3 billion kilograms, and it is estimated that it will increase by 17.4% by 2025. In vitro and in vivo studies have shown that tea polyphenols in tea are beneficial for inflammation and the prevention of chronic diseases, including protection against certain cancers, diabetes, and cardiovascular disease.
However, epidemiological studies have been unable to draw firm conclusions about the relationship between tea drinking and gastric cancer! Recently, in a study devoted to assessing whether tea consumption is associated with gastric cancer risk, researchers launched a “Global Alliance Gastric Cancer Pool” project to re-examine the association between frequent and infrequent tea drinkers and gastric cancer. Were studied.
Is tea good for preventing stomach cancer? Let’s find out more together~
Research published in BJC
Global Big Data Survey: Tea Drinking Linked to Lower Stomach Cancer Risk
The “Global Alliance Gastric Cancer Pool” project included 22 studies from countries around the world, including 9,438 cases and 20,451 control data, analyzed through one-stage and two-stage models, Odds ratios (ORs) and corresponding 95% confidence intervals (95% CI) for gastric cancer in frequent and infrequent tea drinkers were assessed.
The adjusted OR was 0.91 (95%CI: 0.85–0.97) for frequent tea drinkers compared with infrequent tea drinkers; OR from a two-stage analysis Similar to stage one (OR: 0.92, 95%CI: 0.82–1.05), heterogeneity I2=62% (Fig. 1).
Figure 1 The OR and corresponding 95%Cl of gastric cancer in people who drink tea regularly compared to people who drink tea infrequently
In addition, the researchers looked at the amount of tea consumed. They found that people who drank 3 or more cups of tea pera day were more prominent and had a 9% lower risk of stomach cancer, with an OR of 0.91 (95%CI: 0.80– 1.03). However, no significant association was found among those who drank 1-2 cups of tea per day, with an OR of 1.01 (95% CI: 0.94–1.09) (Figure 2).
Figure 2 The OR of gastric cancer and the corresponding 95% Cl in people who drink tea frequently compared with people who drink tea infrequently (among people who drink tea frequently, a: drink 1-2 cups of tea per day , b: drink 3 cups of tea or more per day)
These 3 types of people who drink tea regularly: reduce the risk of stomach cancer by more than 30%!
In addition to the relationship between tea drinking and gastric cancer risk reduction, the researchers conducted a stratified analysis and found that in the following three conditions, there was a significant relationship between tea drinking and gastric cancer. The negative correlation is worthy of our attention (Figure 3)!
Figure 3 Hierarchical Analysis
Geographic region: Asians who drink tea regularly have a reduced risk of gastric cancer, OR 0.62 (0.95%CI: 0.48-0.81), a striking 38 reduction in gastric cancer risk %! And this phenomenon is also more prominent in the study only in China, Japan or Iran, China and Japan OR is 0.67 (95%CI: 0.49-0.91); Iran’s OR is 0.50 (95%CI: 0.29-0.86);
Helicobacter pylori(Hp)Infection:We know that Hp infection It is one of the risk factors of gastric cancer, and the data of the study found that the risk of gastric cancer in H. Compounds that inhibit bacterial growth. p>
Cardia cancer: Similar to H. pylori infection, the risk of gastric cancer in patients with cardia cancer who regularly drank tea was also reduced, OR was 0.64 (95%CI: 0.49) –0.84).
Finally, the researchers used natural cubic splines to fit the dose-response relationship between the number of tea cups (as a continuous variable) and gastric cancer, and found that as tea drinkers increased Increasing the amount of tea consumed daily from 3 cups decreased the risk of gastric cancer (Figure 4). This indicates that under the condition of drinking more tea, the protection level of tea drinking on gastric cancer is gradually increasing.
This also corresponds to the geographical factors mentioned above: green tea is common in China and Japan, black tea is popular in Iran, and people in these countries are particularly able to drink tea, in other words, The level of protection against gastric cancer is so remarkable that the amount of tea drinking is larger!
Figure 4 The dose-response relationship between the number of tea cups and gastric cancer
What are the benefits of drinking tea?
A meta-analysis found that drinking all types of tea was associated with a reduced risk of several cancers including stomach, colorectal, biliary tract, liver cancer and more , but the key evidence is still insufficient, only the association with oral cancer has sufficient evidence.
But on “what else is good for drinking tea?”, researchers have long discovered that antioxidants in tea can help reduce the risk of cancer, such as tea polyphenols, Catechins, which act as reactive oxygen species scavengers, can affect the activity of transcription factors and enzymes.
Among them, epigallocatechin gallate (EGCG) is the most abundant catechin and is believed to play a crucial role in inhibiting the occurrence and progression of cancer. Tea polyphenols can inhibit the growth of cancer cells through various mechanisms, such as inducing cancer cell apoptosis, inhibiting receptor-dependent signaling pathways and angiogenesis, silencing genes associated with epigenetic mechanisms (such as DNA methylation), and Inhibit enzyme activity.
In this way, there are many benefits of drinking tea, so for certain groups of people or risk groups, you might as well have a cup of hot tea in your spare time~