Researchers at the University of Buffalo compared the health outcomes of breast cancer patients who ‘never or rarely drank non-diet soda’ with those who reported drinking non-diet soda five times or more per week.
The study, published in Cancer Epidemiology, Biomarkers & Prevention, found those who drank sugar-sweetened beverages regularly were at increased risk of death from any cause – and faced higher breast cancer mortality rates in particular.
Researchers assessed the relationship between sugar-sweetened soda and both all-cause and breast cancer mortality among 927 women who had been diagnosed with breast cancer, aged 35 to 79. Participants were enrolled in the Western New York Exposures and Breast Cancer (WEB) Study and were followed for a median of nearly 19 years.
The study used a food frequency questionnaire to assess participants' food and beverage intake in the 12 to 24 months prior to diagnosis of breast cancer.
Of the women diagnosed with breast cancer, 41% had died by the end of the follow-up period. Among the participants who had died, there was a higher percentage of women who reported high frequency of sugar-sweetened soda consumption compared to the women who were still living, the study found.
Women who reported this level of consumption of sugary beverages faced a 62% higher likelihood of dying from any causes and were 85% more likely to die from breast cancer specifically.
The associations did not change when researchers included diet soda consumption as a variable.
Soda consumption has been linked to a number of negative health outcomes, including weight gain, Type 2 diabetes and cardiovascular disease. But research on soda and breast cancer is fairly new, the study’s first author Nadia Koyratty noted. To date, there have been only a few observational studies examining the association between sugar-sweetened beverages and cancer mortality.
"This study is one of the few that looks at the prognosis of women with breast cancer with respect to non-diet soda consumption," Koyratty said.
Koyratty, a PhD candidate in the Department of Epidemiology and Environmental Health in UB's School of Public Health and Health Professions, added that because breast cancer is relatively common, recommendations regarding lifestyle choices to breast cancer survivors are of ‘considerable importance’.
Why the focus on non-diet soda?
"Non-diet sodas are the highest contributors of sugar and extra calories to the diet, but they do not bring anything else that is nutritionally beneficial," Koyratty explained.
"On the other hand, teas, coffees and 100% fruit juices, unless sugars are added, are healthier beverage options because they do add to the nutritive value through antioxidants and vitamins," she suggested.
Sugar-sweetened sodas have a higher glycemic load than other food and drink because they contain large quantities of sucrose and fructose. These higher concentrations of glucose and insulin may lead to conditions that have been associated with higher risk of breast cancer, the researchers noted.
"While we need more studies to confirm our findings, this study provides evidence that diet may impact longevity of women after breast cancer," study senior author Jo L. Freudenheim concluded.
'Sugar-Sweetened Soda Consumption and Total and Breast Cancer Mortality: The Western New York Exposures and Breast Cancer (WEB) Study'
Cancer Epidemiology, Biomarkers & Prevention
Authors: Koyratty, N., et al.