With a few lifestyle adjustments, all women could reduce their breast cancer risk by about 30%, a report has found.
Although great advances have been made in the treatment of breast cancer, the introduction of methods to estimate risk and prevention of the disease have been less successful.
As a result, breast cancer is on the rise in the UK – and the trend is expected to continue until at least 2030.
Risk Determination and Prevention of Breast Cancer, published in the journal Breast Cancer Research, has identified four critical risk-and-prevention research gaps that must be addressed if this predicted rise over the next decade is to be reversed.
The review, facilitated by Breast Cancer Campaign, follows on from the charity’s 2013 Gap Analysis and has identified lifestyle – as well as risk estimation, preventive therapy and biology of risk – as the four crucial gaps.
Breast density, which was highlighted as a significant breast cancer risk factor in the analysis, was a key area of focus. Read more about breast density, and its relevance in estimating breast cancer risk, in this blog for HuffPost UK Lifestyle, by the chief executive at Breast Cancer Campaign, Baroness Delyth Morgan.
In a statement following the report’s publication, Baroness Morgan said: “The emerging evidence on risk factors such as breast density, which we now know is putting hundreds of thousands of women at risk of developing breast cancer, must be taken into consideration and more must be done.”
And to that end, Breast Cancer Campaign has invested around £1m into risk-and-prevention research. But these things take time, which is why awareness around lifestyle factors is of the utmost importance right now.
She added: “Until progress is made on a scientific and clinical level that enables women to be informed about breast density, it remains even more vital that women are aware of the signs and symptoms of breast cancer to look out for and follow the recommended lifestyle advice to lower their risk.”
What are lifestyle risk factors?
Lifestyle risk factors are environmental factors, which unlike genetic or physiological characteristics, are largely within our control. The main lifestyle factors affecting breast cancer risk include weight control, physical exercise and alcohol consumption.
And the link is significant. The World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) has estimated that over 40% of post-menopausal breast cancer could be prevented by reductions in alcohol, excess body weight, and inactivity.
Other lifestyle factors explored in the analysis paper, such as pregnancy and the use of Hormone Replacement Therapy (HRT) for the treatment of menopausal symptoms, are more complex.
Although evidence suggests having children late or not at all can increase breast cancer risk, the report acknowledges there are wider implications to consider here.
It states: “Given global increases in population growth and the strong evidence that a woman’s ability to control her fertil ity may improve her social, economic, and overall health, it is not considered desirable to increase the birth rate per woman or to encourage pregnancies at a very young age.”
However, it goes on to stress the importance of breastfeeding, which can reduce breast cancer risk - and continue to reduce the risk, the longer it is sustained.
Risk Determination and Prevention of Breast Cancer collated a number of studies that highlighted the connection between weight control and breast cancer risk.
In the Iowa Women’s Health Study, sustained weight reduction of 5% of body weight reduced post-menopausal breast cancer risk by as much as 25% to 40% compared with women who continued to gain weight.
Meanwhile, a review of dietary patterns and breast cancer performed by Albuquerque and colleagues, concluded that a Mediterranean dietary pattern – and diets composed largely of vegetables, fruit, fish, and soy – are associated with a decreased risk of breast cancer.
"There is no single superfood that is proven to prevent breast cancer. However, another way to look at it is there are super diets, meaning that it is the combination of a range and variety of healthy foods, which gives you the best chance of reducing your cancer risk,” Annabel Bentley, medical director at Bupa, tells HuffPost Lifestyle.
“A healthy balanced diet is one which includes plenty of fresh fruit and vegetables, fibre, starchy foods, lean proteins and low-fat dairy products.
“A key factor about diet is that being obese increases your risk of breast cancer, so it’s important to eat foods which help you keep to a healthy weight," she adds.
The report – which was compiled by leading scientists and based on recent data and relevant peer-reviewed literature – revealed a number of significant statistics around the effect of physical activity on breast cancer risk.
A review of 73 observational studies indicated that moderate to vigorous physical activity reduces breast cancer risk by an average of 25% in pre- and post-menopausal women.
But despite this known link, women are still failing to meet the requirements. Another study found that over 40% of adult women are not meeting the current guidelines of 150 minutes of moderate or 75 minutes of vigorous physical exercise per week.
The optimal level of physical exercise for breast cancer reduction is still a grey area. But the current recommendation from Breast Cancer Campaign is that women should aim to be physically active at moderate intensities (equivalent to brisk walking) for around 30 minutes, five times per week.
The current NHS recommendations of no more than 2 - 3 units of alcohol a day for women might sound reasonable. But stark figures revealed in Risk Determination and Prevention of Breast Cancer might make you think again before reaching for another bottle of wine.
It is estimated that breast cancer risk is increased by 7% to 10% for each one-unit increase in intake of alcohol per day. In the Nurses’ Health Study, women who consumed four to nine units per week were 15% more likely to develop breast cancer compared to non-drinkers.
Women who drank 27 units of alcohol or more per week (that’s less than three bottles of wine) were more than twice as likely (51% more) to develop breast cancer compared to those who completely abstained.
And although the majority of breast cancer cases are in post-menopausal women, drinking now and cutting back later is not an effective measure. The report warned that lifestyle prevention includes not only middle- and late-age women but younger women after the onset of periods.
Warning that consuming 21 units per week increases breast cancer risk by 40% compared to drinking no alcohol, Breast Cancer Campaign recommends women limit alcohol intake to no more than five units per week to lower their risk of breast cancer.
In light of the risk-and-prevention analysis, Breast Cancer Campaign recommends that Public Health England (PHE) works with NHS Choices and Health and Wellbeing Boards to integrate relevant prevention messages into their broader health messaging and activities.