More cups of coffee lead to smaller "cup size"
Women are having second thoughts about sipping their cup of joe after a study linked coffee intake to smaller breasts. A 2008 study published in the British Journal of Cancer went viral as it connected coffee intake with breast size.
One enzyme is related to both coffee and estrogen metabolism in some women, specifically those born with a specific variant of the CYP1A2*1F gene. Armed with this fact, a group of Swedish doctors led by Helena Jernstrom investigated the relationship between caffeine and breast size in 269 women with a high risk for breast cancer.
Ironically, even as coffee decreases breast size, it also decreases a woman's risk for losing her breasts altogether. But what exactly is present in coffee that influences breasts in the first place?
Coffee compounds that shrink breasts
Although best known for its caffeine content, coffee actually contains other compounds that can influence hormone activity. For instance, it is rich in phytoestrogens that are capable of blocking estrogen receptors in breasts.
Estrogen is a hormone that regulates breast tissue growth and development. But with coffee phytoestrogens beating estrogen to the punch line, estrogen cannot do its job.
Coffee metabolism is linked to an enzyme regulated by the CYP1A2 gene. Coffee drinkers carrying a specific variant of this gene have a higher enzyme expression, leading to higher levels of a “weak form” of estrogen.
Simply put, when a weak estrogen binds with the estrogen receptor, it leads to less significant breast changes. High levels of this weak estrogen, therefore, have a significant relationship with small breast size.
The above effect is seen most especially in women positive for the genotype who drink at least three cups of coffee. The more coffee they drink, the smaller their breasts are.
Bigger breasts, bigger problem
Although many women secretly dream of being one or two cup sizes bigger, a generous chest comes with a price: It may increase one’s chances of having breast cancer in the future.
Breast tissue density is a known breast cancer risk factor. In a study involving over 600 women published in Cancer Causes and Control, the incidence of breast cancer rose proportionately with a woman’s breast size.
Coffee lowers breast cancer risk
Even as coffee seems to shrink the breasts of women with the above genotype, it actually protects them from breast cancer.
The same gene found in women that leads to smaller breasts actually leads to lowers levels of 16α-OHE1, a hormone known to contribute to estrogen-negative breast cancer. Estrogen-negative breast cancer is a type of cancer with fewer treatment options, making this finding an important steppingstone in formulating a holistic and prevention-centric regimen for high-risk females.
Word of advice to women: Don’t ditch coffee just yet. With moderate coffee consumption, you will barely notice any change in the size of your breasts – and you are less likely to lose them to cancer.
Dr. Stef dela Cruz is a health blogger and columnist. She is nominee for the PKKP Media Recognition Awards to be presented by the Department of Health.