New research suggests that proton pump inhibitors (PPIs) may negatively affect cognition in individuals with a history of breast cancer.1
The findings, which were published in the Journal of Cancer Survivorship, found that the commonly-used acid reflux drug may potentially contribute to memory and concentration problems in this population.1
However, in order for a causal effect to be established, the authors noted that further investigation should include a clinical trial controlling PPI doses and obtaining cognitive data.
Previous research has suggested that off-label use of PPIs in patients with cancer may increase tumors’ responsiveness to chemotherapy while protecting the digestive system, but long-term studies on the effects of PPI use in this population are limited.2
The study authors conducted a secondary analysis using data from 3 previous clinical trials examining fatigue, a yoga intervention, and vaccine response in 551 patients with breast cancer and those with a history of the disease. Individuals in the studies reported their use of prescribed and OTC medications and rated their cognitive function throughout the study period. A total of 88 participants reported taking PPIs. Data from both PPI users and non-users were included and the studies controlled for a variety of factors that could affect cognition, including depression or other illnesses, type of cancer treatment, age, and education.1
Across all 3 studies, PPI users reported more cognitive problems overall than non-users. In the first study, PPI users reported more severe concentration problems (p=0.039), but not memory problems (p=0.17) than non-users. PPI users in the second study had more severe concentration problems (p=0.022) compared with non-users, but not memory problems or symptoms on the BCPT (ps=0.11). In study 3, PPI users reported more severe memory problems (p=0.002), poorer overall cognitive function (p=0.006), lower quality of life related to cognitive problems (p=0.005), greater perceived cognitive impairment (p=0.012), and poorer cognitive abilities (p-0.046), but not more severe concentration problems (p=0.16), compared with non-users, according to the study.1
Overall, the findings indicated that cognitive problems reported by PPI users were between 20% and 29% more severe than issues reported by non-users. Additionally, the analysis showed that at least two-thirds of breast cancer survivors using PPIs had been taking them for between 6 months and 2 years.1
“I thought there could be a cognitive effect from taking PPIs, particularly in this population, because breast cancer survivors are already at risk for cognitive decline,” lead author Annelise Madison, a graduate student in clinical psychology at Ohio State University, said in a press release about the results.2 “PPIs are over the counter and generally considered safe so there haven’t been many long-term trials, especially looking at cognitive outcomes, because nobody was really thinking that would be a downstream effect.”
According to Madison, the findings raise more questions regarding the cognitive recovery of PPI users after chemotherapy and warrant further investigation.2
- Kiecolt-Glaser JK, Annelise MA, Woody A, et al. Cognitive problems of breast cancer survivors on proton pump inhibitors. Journal of Cancer Survivorship. 2020. Doi: https://doi.org/10.1007/s11764-019-00815-4
- Acid reflux drugs may have negative side effects for breast cancer survivors [news release]. Ohio State University’s website. https://news.osu.edu/acid-reflux-drugs-may-have-negative-side-effects-for-breast-cancer-survivors/. Accessed January 20, 2020.