Lifestyle and Breast Cancer Prevention

October is Breast Cancer awareness month.  One in twelve Irish women will develop breast cancer in their lifetime.   A sobering statistic.   Exactly what causes breast cancer in some individuals has yet to be established.

It becomes more common as we age, with about 80% of breast cancers occurring in women over 50 years.   While things like age and family history will impact our risk of developing cancer, research is showing that healthy diet and lifestyle may be protective against developing breast cancer, i.e. keeping to a healthy weight for your height and taking regular physical activity.   

The World Cancer Research fund, together with the American Institute of Cancer Research, published a report called ‘Food, Nutrition and the Prevention of Cancer:  a global perspective’ last November 2007.  This report brought together a panel of experts worldwide to assess the current research findings on risk of all types of cancer, and prevention.     Here is a summary of the evidence behind diet, lifestyle and breast cancer risk.

Breastfeeding
The evidence is fairly convincing that breastfeeding during ones lifetime protects against developing breast cancer at any age, whether pre or post menopausal.    And most studies show the longer you breastfed for, the stronger the protective effect.    Hormonal changes and physical changes in breast tissue cells may be responsible for this decrease in risk.  

Physical activity
Evidence to date shows that physical activity probably protects against developing breast cancer post menopausally.  Those who take more exercise seem to have lower risk.  The research has yet to pinpoint exactly how much or what type of exercise is best.  Therefore, its best to ensure you are taking at least the recommended 30 minutes a day, whether its walking, jogging, cycling, swimming, skipping, or even gardening.    

Body fatness
Curiously, body fatness may be protective against developing breast cancer pre-menopausally.  But before you go to reach for that muffin read on:  there is robust evidence to show body fatness increases risk of developing breast cancer in post menopausal women.   As breast cancer is more commonly diagnosed post menopause it is therefore more advantageous to keep your body fat low as you move through life.   Indeed, weight gained during adulthood, in particular around the waist (i.e. apple shaped) may also increase your risk of developing breast cancer post menopausally.   Keep your weight stable by following a regular eating pattern, reducing your portions, eating more plant based foods and less fat.   

Alcohol
Alcohol increases breast cancer risk at any age, whether pre or post menopausal.   There are a number of reasons why this is so.   The breakdown products of alcohol in the body, such as acetaldehyde (which also contributes to a ‘hangover’), may be carcinogenic.   In addition, alcohol acts as a solvent, promoting penetration of carcinogens, or cancer promoting agents, into the cells in our body.    Furthermore, alcohol also interferes with hormone regulation in the body.  And finally, big drinkers generally have diets low in essential nutrients – reducing the body’s own cancer protective abilities.    The research has not been able to define specifically if what is a safe amount of alcohol.   The Department of Health and Children in Ireland advises that a weekly limit of up to 21 standard drinks for men and 14 standard drinks for women is considered low risk for health in general.    However, it is important that these drinks are spread out over the week and not all taken on a Saturday night!   Also, this is a maximum, not a target.  One standard drink is a ½ pint of beer, 100ml glass of wine or 1 pub measure (35.5ml) of spirits.  Check out www.drinkaware.ie if you want to find out more about alcohol and its effects on the body.  This site also has a useful ‘how many drinks’ interactive calculator which allows you to count up exactly how many standard drinks you are taking each week.  

All of these breast cancer risk factors/protectors are within our control, and therefore these are the factors we should focus on.  

Log onto the  Irish Cancer Society’s ‘Action Breast Cancer’ website for more information about breast cancer and to get a free breast awareness information pack.  http://www.cancer.ie/action/


© Joanne Corbett, BSc, DBS, MSc, MINDI