12 January 2018
This is a very common question in the Breast Clinic. Quite understandably, many women are keen to understand what choices they can make that may influence their risk of developing breast cancer. Although the question seems straightforward, as is often the case in life, the answer is more complicated.
The two biggest risk factors for developing breast cancer are a) being a woman b) age. Neither of these two risk factors can be changed and they dwarf all the other potential risk factors by a large amount. Although this may sound dispiriting there are areas where women’s choices can influence the risk of developing breast cancer. These largely centre around lifestyle choices.
There is a large body of research developing around lifestyle and the risk of developing certain cancers. The commonest and most well known link between lifestyle choice and cancer risk is cigarette smoking and the development of lung cancer. This is a very strong link. In breast cancer no such indisputable link between lifestyle and cancer risk has yet been proven. Instead, in breast cancer we have a number of associations. Certain behaviours are associated with the risk of developing breast cancer. This is different to there being an accepted scientific proof of causation such as in cigarettes and lung cancer.
Alterations in these behaviours are thought to alter the risk of developing breast cancer. Remember, these alterations are small in influence compared to the two major risk factors of gender and age. Nevertheless, they are behaviours a woman can control or modify if she wishes to. Some of these associations are discussed in this article.
Weight, weight gain and weight loss
Many studies link being overweight or obese to an increased risk of developing breast cancer in postmenopausal women. Women who gain weight during their later adult life (as opposed to adolescence or early adulthood) seem to have a higher incidence of breast cancer. Losing weight reduces risk. Even a small reduction of around 5 to 10% of weight can have a beneficial reduction in breast cancer risk.
There is an association between alcohol consumption and breast cancer risk. Consumption of alcohol on a daily basis is estimated to increase breast cancer risk.
How much alcohol is needed to result in this increase? This is not precisely known. Increasing daily intake is associated with an increasing risk up to 6 units a day. Drinking more than 6 units daily does not seem to further increase breast cancer risk (however, this level of alcohol consumption will cause undoubted harm to health in other ways).
Exercise is proven to be tremendously beneficial to health in a huge number of ways. In terms of breast cancer risk reduction further research is needed. Currently, it appears that around 180 minutes of moderate intensity exercise per week will potentially result in a reduction of breast cancer risk. This risk reduction is seen in both pre and post menopausal women.
Research evidence emerges all the time and the level of association between diet and breast cancer risk remains an area of development. The following is a snapshot of the latest findings
- Fruit and vegetables
There is consistent evidence of a beneficial link between fruit and vegetable intake and heart disease. The link between fruit and vegetables and cancer risk is more hotly debated. Recently a link has emerged between increasing consumption of dietary fibre and a lowering of breast cancer risk.
- Meat and fish
High consumption of red or processed meat (100g or more per day) results in a small breast cancer risk increase. However vegan or vegetarian diets do not seem to influence breast cancer risk. The fats found in fish, especially oily fish, may provide some beneficial risk reduction.
It is entirely possible that the associations mentioned between meat/fish and breast cancer risk are not to do with the foods themselves but are seen as a part of an overall “package” of an unhealthy lifestyle.
- Dairy foods
There is much misinformation on the link between consumption of dairy products and breast cancer risk. Some argue that increasing consumption of dairy products results in increased risk of breast cancer.
If we stick to the scientific evidence we can see that this is just not true. In fact there may even be a protective effect of dairy foods by reducing breast cancer risk.
- Vitamin supplements
Vitamin supplements have no effect on breast cancer risk at all.
For years it has been thought that smoking, despite all its terrible effects on other aspects of human health, played no part in breast cancer risk. Recently the mood music around this has changed. There is now thought to be a weak link between cigarette smoking and the development of breast cancer especially if started during teenage years or early adulthood.
The above is intended to keep women informed of what element of breast cancer risk may potentially be modified. As already mentioned, the two most important and over riding elements, age and gender, cannot be changed. Therefore no woman who develops breast cancer should ever feel guilty because she did not follow “a healthy lifestyle”. This should be the most important message from this article.
Written by Mr A Gandhi, Consultant Breast Surgeon.
For more information or to book an appointment with Mr A Gandhi, please contact 0161 447 6700 or email firstname.lastname@example.org
The content of this article is provided for general information only, and should not be treated as a substitute for the professional medical advice of your doctor or other health care professional.