Breast cancer is the most common cancer affecting Australian women. There are a number of known factors that increase a woman’s risk of breast cancer including having a strong family history, being overweight and drinking alcohol.

There are many hypotheses publicised about different foods and the effects that they may or may not have on breast cancer risk. It’s important to consider the available evidence to review whether or not there is merit to any of these claims often publicised in the media.

Researchers examined the validity of one of these assertions, namely that increased dietary fibre intake in adolescence and early adulthood reduces a woman’s risk of breast cancer.

Data were analysed from the Nurses’ Health Study II – an ongoing study that started in 1989 and involves more than 100,000 female registered nurses. Participants completed a general diet questionnaire in 1991 and every four years thereon after.

They also completed a questionnaire in 1997 that asked questions about the women’s diets and frequency of food consumption during their high school years.  Any diagnoses of breast cancer were recorded over time.

The results showed an association between fibre intake in early adulthood and lower breast cancer risk.

Similarly, higher fibre intake during adolescence was associated with lower breast cancer risk. Researchers outlined possible explanations for these results including the potential for fibre to improve insulin sensitivity and decrease levels of circulating oestrogen.

Implications

The results of this study suggest that dietary fibre intake may help minimise risk of breast cancer however as with all observational data a cause-and-effect relationship cannot be assumed.

Nevertheless, fibre from fruits, vegetables and whole grains are a valuable addition to a healthy diet for a variety of positive health outcomes.

It’s important to be aware of any family history of breast cancer and take appropriate precautions if you’re at increased risk.

Keep aware of current recommendations regarding who should get screened and at what stages of life this should happen.

Visit the Royal Australian College of General Practitioners website for good information: http://www.racgp.org.au/your- practice/guidelines/redbook/early-detection-of-cancers/breast-cancer

Last Reviewed: 03/09/2019

© Norman Swan Medical Communications.



References

Farvid, M et al. Dietary Fiber Intake in Young Adults and Breast Cancer Risk. Pediatrics DOI: 10.1542/peds.2015-1226. Originally published online February 1, 2016.