This extreme like or dislike is as controversial as whether coffee causes cancer or prevents cancer.
199 1, coffee is classified as "possibly carcinogenic to human beings"; In 1996, coffee has been downgraded to "cannot be classified as a carcinogen" by the International Agency for Research on Cancer of the World Health Organization.
Is there a link between drinking coffee and getting breast cancer? The results of various epidemiological studies are still controversial. In addition, the composition of coffee is different in various coffee products, such as instant coffee and freshly ground coffee, which will have different effects on the occurrence of breast cancer.
Recently, Scientific Reports, an authoritative academic journal in the world, published a paper online.
Relationship between coffee products and breast cancer risk: A case-control study in Hongkong, China.
Different from many previous studies, this study is not aimed at Europeans and Americans, but mainly at China and Hongkong women, which can provide reference for mainland women. In this study, 2 169 China women aged 24-84 in three public hospitals in China and Hongkong were interviewed by standardized questionnaires, and the types, cups and duration of coffee they drank were investigated. Unconditional multivariate logistic regression model was used to calculate the risk ratio of different coffee products and breast cancer.
Q: Why does drinking coffee reduce the risk of breast cancer?
One mechanism may be related to the abundant polyphenols in coffee (such as caffeic acid and chlorogenic acid), which may inhibit the promoter and methylation of breast cancer-related gene RAR-β, which may be a bit difficult to understand. Generally speaking, some substances in coffee can inhibit the activity of breast cancer-related genes.
Another mechanism may be related to high levels of caffeine intake, because caffeine can reduce the level of estrogen in the blood, and we know that high levels of estrogen are related to a significant increase in the risk of breast cancer.
Q: Why are postmenopausal women more obvious?
Premenopausal ovarian function is vigorous, so it may be useless to reduce the risk of breast cancer by lowering estrogen levels with caffeine. For postmenopausal women, the production of estrogen comes from the transformation of androgen in adipose tissue, and the production is limited. Caffeine may bind estrogen by increasing the level of sex hormone binding globulin in postmenopausal women, thus significantly reducing the estrogen content in blood. Therefore, caffeine can reduce the risk of breast cancer in postmenopausal women more obviously than in premenopausal women. Some meta-analyses from other countries also show that there are other potential protective substances or effects in coffee, which only affect postmenopausal women.
Q: Why can drinking freshly brewed coffee in restaurants better reduce the risk of breast cancer?
Another possible mechanism of newly brewed coffee reducing the risk of breast cancer is the role of diterpenoids.
The content of diterpenoids varies with different coffee making methods. The content of two special coffee diterpenoids, namely caffeic alcohol and coffee bean fat, in brewed coffee is higher than that in filtered coffee. These two diterpenoids have biochemical effects, such as inducing binding enzymes, increasing the expression of protein in cell antioxidant defense, which may lead to the decrease of genotoxicity of several carcinogens. In other studies, it has also been suggested that the risk of breast cancer in women who are used to drinking brewed coffee is significantly reduced, but the risk of breast cancer in women who are used to drinking filtered coffee is not significantly reduced. Therefore, women who often drink freshly ground coffee in restaurants have a lower risk of breast cancer. And although some coffee made at home is also brewed coffee, many of them may be just a kind of filtration, which can't really be called brewing.
Key tips
1
Coffee itself can reduce the risk of breast cancer, but instant coffee will increase the risk of breast cancer because of adding a lot of unhealthy substances, which is not good for other people's health, so you must not drink instant coffee, especially two-in-one or three-in-one coffee mixed with sugar and partners.
2
Research shows that restaurant coffee actually means making coffee. In fact, such slow-brewed coffee is rare in the fast-paced modern life. Many fast-food coffee shops, including Star Dad, do not brew coffee strictly, and most of them brew espresso obtained by filtering coffee powder with high-pressure steam. Of course it's not instant coffee, but it's ok to drink it. If you want to drink cooked food, you may want to go to a lazy coffee shop.
Therefore, you can drink coffee at any time. As long as it's not instant coffee, it's not harmful to the breasts. You can make your own coffee or order some fresh coffee if you can. In the leisure afternoon, it is also a wonderful and rare time to spend some time making coffee, getting some snacks and spending a lazy afternoon with your beloved people or friends.
Tao sifeng
Deputy chief physician of breast surgery, Second Hospital of Zhejiang University, doctor of surgery, postdoctoral fellow in oncology. He is good at the diagnosis and treatment of all kinds of benign and malignant breast tumors, and carries out breast-conserving surgery, radical surgery and plastic surgery for all kinds of breast cancer. In-depth study on the comprehensive treatment of breast cancer, and unique views on the treatment of benign tumors of young women and mastitis during lactation.
Outpatient time: Monday morning and Wednesday afternoon (Jiefang Road Campus); Tuesday afternoon (Binjiang Campus); Wednesday morning (international campus)
(Original title "Drinking coffee can significantly reduce the risk of breast cancer! But it's not Star X, it must be this coffee ... ". Editor Wang Rongrong)