Diet After Breast Cancer: spotlight on sugar and fiber
by Dr. Jessica Moore, ND
When breast cancer treatment ends, many patients are told they can “go back to their normal diet.” However, resuming or starting unhealthy dietary and lifestyle habits may promote mechanisms thought to increase the risk for recurrence or progression. Research has demonstrated a trend towards weight gain after breast cancer treatment. Obesity, overweight status, diabetes and insulin resistance are associated with a poorer prognosis for breast cancer survivors. These conditions are also risk factors for heart disease and diabetes.
A critical piece of dietary education for breast cancer survivors should be to avoid excessive carbohydrate intake, which can lead to spikes in blood sugar, insulin, insulin growth factor and inflammation. These can potentially stimulate the growth of cancer cells and promote conditions associated with worse outcomes as mentioned above.
An important first step may be to replace simple carbohydrates with complex ones. Both will break down into sugar but there are some critical differences. Simple carbohydrates are refined, processed and absorb quickly into the blood steam. They are low in nutritional value and include things like soda, fruit juice, white flour, white bread etc. Complex carbohydrates contain fiber which can slow the absorption of sugar into the bloodstream and may also support gastrointestinal health. You will find complex carbohydrates in whole foods such as peas, beans, whole grains, sweet potato and vegetables.
Researchers looking at cancer prevention have suggested that for every 20g of fiber consumed daily there might be an associated ~15% reduced risk for breast cancer. Health Canada suggests most Canadians are getting only ½ of their minimum needed daily fiber. They suggest Canadian women need 25 grams, and men need 38 grams, of fiber per day. I frequently recommend higher amounts, but this should be prescribed on an individual basis, especially after cancer treatment or if you have any issues with your gastrointestinal health.
While there is no single diet plan appropriate for every person with a history of breast cancer, plant-centric diets, robust in vegetables, berries and other fruit, fiber, olive oil, spices, polyphenols and antioxidants appear favorable. A Mediterranean diet has demonstrated reduced risk for breast cancer recurrence, compared to a standard diet. Research looking at intermittent fasting and or a ketogenic diet is promising.
Individuals who have been treated for breast cancer deserve a carefully considered survivorship plan of care. As part of a comprehensive work-up I utilize basic blood work as well as nutrigenomic, hormone and or other advanced testing to better understand a person’s unique biochemistry and metabolic health. The goal is to personalize nutrition support, life-style practices, targeted supplementation and non-toxic therapies to optimize cellular terrain and reduce recurrence risk.
**The information in this article should not be taken as medical advice. Please talk with your doctor or healthcare provider before making any changes to your diet or lifestyle.
References: Nutr Rev. 2016;74(12):737-748; BMC Cancer 20, 113 (2020); Med Sci (Basel). 2017;5(2):12.; Cancer Epidemiol Biomarkers Prev. 2014;23(7):1273-1279; Health Canada. Fibre. https://www.canada.ca/en/health-canada/services/nutrients/fibre.html Accessed Aug 15, 2020; J Natl Cancer Inst. 1990;82(7):561-569.; J Clin Oncol. 2016;34(suppl; abstr e13039).