Lifestyle, More than Genetics, Increases Breast Cancer Risk
An ongoing British study reveals that white women are more likely than their black or South Asian counterparts to be diagnosed with breast cancer. But it’s not genetics that increases risk – it’s lifestyle. And lifestyle can be changed.
Whenever results of a study of any kind – medical or socioeconomic – make the news, and the study involves distinctions by ethnicity, our first reaction is probably, “Well, genetics can be pretty interesting; who’d think you were born with a tendency for…” fill in the blank. Having fewer children. Under-performing on standardized college tests. Becoming an alcoholic.
Thus at first glance, black or South Asian women hearing the results of an ongoing British study might have breathed a sigh of relief on finding that they’re around 18% less likely to develop breast cancer than their white neighbors.
On the other hand, white women reading the study would be dismayed to discover they’re statistically more likely to be diagnosed with breast cancer than black or South Asian women.
“Accident of birth,” we think. Some of us happy; some not.
In fact, the disparity among races involving these breast cancer risk statistics isn't genetic at all; it's based on lifestyle, as the study convincingly proves.
Great Britain’s Million Women study, actively carried out by University of Oxford researchers from 1996-2001 (with results due to be tracked through 2018), examines not just participants’ ethnicity, but their lifestyle. And, once lifestyle differences have been factored into the data, it’s become clear that the difference in breast cancer risk among all ethnic groups is statistically insignificant; risk rises and falls largely based on choices women make throughout their life, rather than on the genes they’re born with.
In fact, study authors conclude that in Great Britain, as more and more black and South Asian women move into and adopt a middle-class lifestyle, their breast cancer risk rises to match that of white women.
So, what does this mean to you – whether you’re black, South Asian, white, or Hispanic (a group not covered in the Million Women study, but whose breast cancer risk, in America, falls between that of black and Asian women)?
It means you should understand which risk factors you can influence – and then make sure you do what you can to mitigate them.
Yes, there are some risk factors that can’t be influenced: for instance, age of first menstrual period. Height. A family history of breast cancer.
But others are potentially under your control. Such as drinking alcohol. Taking hormone replacement therapy to get through menopause. Using contraceptive drugs. Your age at first pregnancy, the number of children you bear, and whether you breastfeed them.
And being overweight – the toughest challenge of all for so many of us.
Do you want to lower your risk of breast cancer? Well, it’s the same old story, but one worth repeating. Don’t drink – or at least cut back your alcohol consumption as much as possible. Eat a healthy diet and exercise regularly, to maintain a healthy weight. Don’t use hormone replacement therapy; or if you desperately need to, take the lowest dose possible for the shortest amount of time.
If you’re a young woman, consider not waiting too long to become pregnant. And if you do have a child, choose to breastfeed rather than resort to formula.
Other decisions – using birth control drugs, how many children to have – are more complicated, with long-range implications way beyond cancer. But you might want to factor breast cancer risk into these decisions, as well – simply as one more piece of the puzzle.
Beral, V. (2003, October 18). Breast cancer and hormone-replacement therapy: the million women study. Retrieved from http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(03)14596-5/fulltext
Dixon, H. (2014, January 08). White women more likely to get breast cancer because of 'lifestyle'. Retrieved from http://www.telegraph.co.uk/health/healthnews/10557743/White-women-more-likely-to-get-breast-cancer-because-of-lifestyle.html
Latest research from the million women study: july 2013. (2013, July). Retrieved from http://www.millionwomenstudy.org/study_progress/
Travis, R. (2010). Gene–environment interactions in 7610 women with breast cancer: prospective evidence from the million women study. Retrieved from http://www.millionwomenstudy.org/publications/334/gene-environment-interactions-in-7610-women-with-breast-cancer-prospective-evidence-from-the-million-women-study/