Diets that promote hyperinsulinemia and inflammation may increase the risk for aggressive prostate cancer (PCa), according to a new study.
A team led by Benjamin C. Fu, PhD, of Harvard T.H. Chan School of Public Health in Boston, prospectively followed 41,209 men in the Health Professionals Follow-up Study (1986 to 2014). They calculated scores for 2 validated dietary patterns from food frequency questionnaires that participants completed at baseline and updated every 4 years.
They calculated hyperinsulinemic and inflammatory diet scores based on the propensity of various foods to cause hyperinsulinemia and inflammation.
A total of 5929 incident cases of PCa developed during 28 years of follow-up, including 1019 advanced and 667 fatal cases. On multivariable analysis, each 1 standard deviation (SD) increase in a hyperinsulinemic diet was significantly associated with a 7% and 9% higher risk for advanced and fatal PCa, respectively, Dr Fu’s team reported.
When the investigators stratified participants by age, they found that a hyperinsulinemic diet was significantly associated only with earlier-onset (younger than 65 years) aggressive PCa. Each 1 SD increase was significantly associated with a 20% and 22% increased risk for advanced and fatal PCa, respectively.
An inflammatory diet was not associated with PCa risk in the overall cohort, but was significantly associated with earlier-onset lethal PCa.
“Avoiding dietary patterns with insulinemic or inflammatory potential may be beneficial for the prevention of clinically relevant prostate cancer, especially among younger men,” Dr Fu and colleagues concluded in European Urology.
The investigators noted that hyperinsulinemia and inflammation are interrelated biologic pathways that link diet with the risk for several cancers, with some evidence suggesting that these may also increase PCa risk. Hyperinsulinemia may promote tumor progression directly through insulin receptors or regulation of insulin-like growth factors and their binding proteins, which are involved in cell proliferation and survival, the investigators explained.
An inflammatory diet may contribute to PCa etiology through tissue-level inflammation, “as prostatitis is particularly common among younger and middle-aged men and inflammation is frequently observed in prostate tumor biopsies,” they wrote. In addition, various studies have documented associations between circulating inflammatory biomarkers and PCa risk.
Fu RC, Tabung FK, Pernar CH, et al. Insulinemia and inflammatory dietary patterns and risk of prostate cancer. Published online January 6, 2021. Eur Urol. doi:10.2016/j.eururo.2020.12.003