SUMMARY: Breast cancer is the most common cancer among women in the US and about 1 in 8 women (12%) will develop invasive breast cancer during their lifetime. Approximately 284,200 new cases of breast cancer will be diagnosed in 2021 and about 44,130 individuals will die of the disease, largely due to metastatic recurrence. It is estimated that more than 3.5 million breast cancer survivors are alive in the US. Understanding risk factors and modifying lifestyle behaviors can impact outcomes in this patient group.
Consumption of sugar-sweetened beverages has significantly increased over the past 3 decades worldwide, increasing the risk of obesity, hypertension and Type 2 diabetes, and in turn impacting cardiometabolic health. It is estimated that among all worldwide yearly deaths from diabetes and cardiovascular diseases, over 178,000 were attributable to sugar-sweetened beverages consumption.
More recently published large prospective French study (BMJ 2019;366:l2408) concluded that consumption of sugary drinks was positively associated with the risk of overall cancer and breast cancer. It has been hypothesized that sugar-sweetened beverages contain large quantities of sucrose and fructose which promote visceral adiposity, which can boost tumorigenesis through alterations in adipokine secretion and cell signaling pathways, independent of body weight. Further, long term consumption of sugary drinks result in high glycemic index or glycemic load, with chronically high blood glucose, and therefore chronically elevated insulin concentration. Insulin increases bioactive IGF-1, as well as proinflammatory markers, such as C reactive protein, and systemic inflammation is thought to promote cancer development by inhibiting apoptosis and stimulating cell proliferation, thereby increasing the risk of several cancers, including breast, liver, pancreas, endometrium, colorectal and bladder. Even though there is growing evidence of an association between sugar-sweetened beverages and increased risk of mortality in various populations, the effect of sugary drinks on mortality among breast cancer patients is unknown.
The researchers in this Western New York Exposures and Breast Cancer (WEB) Study assessed the relationship between sugar-sweetened soda and both all-cause and breast cancer mortality among 927 women between ages 35 to 79, who had been diagnosed with breast cancer. In this study, a food frequency questionnaire was used to assess frequency of sugar-sweetened soda consumption in the 12 to 24 months prior to diagnosis of breast cancer. Breast cancer cases were followed for a median of 18.7 years, with ascertainment of vital status via the National Death Index (NDI). This study focused on sugar-sweetened soda, as they are sugar loaded and add extra calories to the diet with no nutritional benefit.
Consumption of sugar-sweetened soda five times or more per week was noted to result in a 62% higher likelihood of dying from any cause and 85% more likely to die from breast cancer specifically, compared to women who never or rarely consumed sugar-sweetened soda. The risk of mortality was similarly increased among ER-positive, but not ER-negative patients, among women with BMI above the median, but not below the median. The risk of total mortality was higher in premenopausal women but not post-menopausal women.
It was concluded from this study that a higher frequency of sugar-sweetened soda consumption was associated with increased risk of total and breast cancer mortality among breast cancer patients, supporting existing guidelines on reducing consumption of sugar-sweetened beverages, including for women with a diagnosis of breast cancer. The authors added that this study provides evidence that diet may impact longevity of women after breast cancer.
Study Finds Regularly Drinking Sugar-Sweetened Soda May Increase Total and Breast Cancer Mortality. Koyratty N, McCann SE, Millen AE, et al. Cancer Epidemiol Biomarkers Prev March 2 2021 DOI: https://doi.org/10.1158/1055-9965.EPI-20-1242.
