Consuming More Flavanoids May Improve Survival After CRC

An increased intake of a type of flavonoids called flavan-3-ols after colorectal cancer diagnosis was associated with decreased mortality, according to study results published online ahead of print in The American Journal of Clinical Nutrition.

“Small, readily achievable increases in the intake of flavan-3-ol–rich foods, such as tea, may help improve survival in patients with colorectal cancer,” wrote corresponding author Mingyang Song, MD, ScD, Harvard T.H. Chan School of Public Health in Boston, Massachusetts, and coauthors.

The study looked at flavonoid intake and survival in 2552 participants diagnosed with stage I through stage III colorectal cancer from the Nurses’ Health Study and the Health Professionals Follow-up Study. Researchers used validated food frequency questionnaires to prospectively assess patient intake of total flavonoids as well as flavonoid subclasses. The average age of patients was nearly 69.

Over 31,026 person-years of follow-up, 1689 deaths occurred, according to the study, 327 of which were due to colorectal cancer.

“The total flavonoid intake was not associated with mortality,” researchers reported, “but a higher intake of flavan-3-ols was suggestively associated with lower colorectal cancer-specific and all-cause mortality, with multivariable hazard ratio (95% CI) per 1-standard deviation increases of 0.83 (0.69–0.99; P = 0.04) and 0.91 (0.84–0.99; P = 0.02), respectively.”

The relationship between flavan-3-ol intake after diagnosis and mortality from colorectal cancer was linear, analysis showed.

The study identified tea as a major contributor of flavan-3-ol intake among participants. Hazard ratios for mortality with one cup of tea per day were 0.86 for mortality specific to colorectal cancer and 0.90 mortality from any cause, researchers found.

“No beneficial associations,” they wrote, “were found for other flavonoid subclasses.”

Reference
Shi S, Wang K, Zhong R, et al. Flavonoid intake and survival after diagnosis of colorectal cancer: a prospective study in 2 US cohorts. Am J Clin Nutr. Published online April 1, 2023. doi:10.1016/j.ajcnut.2023.03.026