October is breast cancer awareness month - so lets talk about lifestyle and breast cancer!
How common is breast cancer?
Breast cancer is the most common cancer in women across the world and it is the most common cancer in the UK. Almost 1.7 million new cases were diagnosed in 2012 worldwide, representing 12% of all new cancer cases and 25% of all cancers in women (World Cancer Research Fund - WCRF). In the UK, one in eight women will develop the disease at some stage in their life (Cancer Research UK). It can also happen in men, but this is very rare.
What causes breast cancer?
Due to the increased awareness of breast cancer and its genetic link, thanks to well-known celebrities like Angelina Jolie, a lot of people think that their risk of getting breast cancer is mostly down to their genes. However, only 3% of breast cancer cases in women are due to their genes. There are many reasons why breast cancer can develop and hormones, particularly oestrogen, can influence the development and growth of some breast cancers. Therefore, life events that affect your hormone levels, such as pregnancy or the menopause, can alter your cancer risk.
Lifestyle factors have a big impact on your risk of developing breast cancer. Scientists estimate that lifestyle factors including maintaining a healthy weight, being physically active and not drinking alcohol could prevent around two in five breast cancer cases in the UK. That is 20,000 cases per year (WCRF)!
The WCRF analyses worldwide research on how lifestyle factors including diet, nutrition, physical activity and weight affect the risk of developing cancer. They produced an up to date report in May 2017 on how lifestyle factors affect the risk of breast cancer which can be seen in the link below. There are some different factors affecting the risk of breast cancer before and after the menopause such as being overweight and obese.
Summary of lifestyle risk factors:
- Being overweight or obese (for post-menopausal breast cancer only).
- Adult weight gain.
- Drinking alcohol.
- Not doing enough exercise.
- Not breastfeeding after having a baby.
So how can you reduce your risk of breast cancer?
1. Cut down on your alcohol intake, or even better don’t drink at all
There is strong evidence that drinking alcohol increases your risk of breast cancer where one in five breast cancers could be prevented if we didn't drink any alcohol. Scientists are still researching how alcohol can cause cancer. One theory is that when alcohol is broken down in our bodies, harmful compounds are formed that might directly damage the DNA in our cells, which can then lead to cancer. Alcohol is even more harmful when combined with smoking and it provides empty calories so contributes to weight gain. To protect yourself against cancer it is best not to drink at all. However, if you do, then try to stay within the recommended UK guidelines of drinking <14 units a week, spread over at least 3 days (seven drinks a week). This factsheet explains more benefits of cutting down on your alcohol intake and useful tips to do so:
2. Be a healthy weight
Surprisingly, there is evidence that being overweight or obese in adulthood before the menopause can reduce the risk of breast cancer before the menopause. However, being a healthy weight and avoiding weight gain throughout adulthood are important in decreasing your risk of breast cancer after the menopause. As post-menopausal breast cancer is the most common type of breast cancer (80% of cases) and we know that being a healthy weight helps to prevent 10 other common cancers in addition to type 2 diabetes and heart disease, we should, therefore, try to be a healthy weight. Being overweight or obese can increase your risk of cancer by encouraging the body to produce growth hormones or other hormones, like oestrogen, which can promote the growth of cancer cells. This booklet gives you useful tips and practical ways you can lose weight:
3. Be more active
Vigorous physical activity lowers the risk of premenopausal breast cancer and every type of physical activity (moderate and vigorous) reduces the risk of postmenopausal breast cancer. Physical activity is important to reduce our cancer risk, but it also has so many other health benefits including lowering our risk of heart disease, stroke and diabetes. Regular exercise is also a great stress reliever and helps to boost your mood. Being active for 30 minutes a day at least five times per week could prevent one in eight cases of colon and breast cancer. Regular exercise can help to lower our insulin resistance, regulate our hormone levels and help us to maintain a healthy weight. This booklet produced by the WCRF gives you lots more ideas, includes plans to help you track your progress, and tells you how much calories you burn per 30 minutes of different types of activities:
4. Breastfeed your baby if you can
Breastfeeding is good for your baby’s health and it can also help protect you against breast cancer. It can help you to lose any excess baby weight more quickly, lower the levels of some cancer-related hormones in your body and get rid of any cells in your breasts that may have DNA damage. If you can, it is advised that you breastfeed your baby exclusively for six months and then continue to breastfeed alongside introducing other foods.
Breast cancer survivors should also try to eat a healthy diet, maintain a healthy weight and do regular physical activity to reduce the risk of getting cancer again. This leaflet includes everything you need to know about reducing your risk of breast cancer based on the most up to date research across the world.
1. World Cancer Research Fund
2. Cancer Research UK
3. World Cancer Research Fund UK
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About Andrea Davis
Andrea is a specialist cancer dietitian. She completed a Masters in Dietetics at King's College London and she has worked in a number of large London Hospitals. Andrea has been invited to deliver lectures on diet and cancer later this year at London Metropolitan University. She is a member of the HCPC and the British Dietetic Association.