Is high intake of whole grains associated with lower risk of developing liver cancer?

Media
Whole grains might help ward off liver cancer
Linda Carroll

(Reuters Health) - Yet another benefit of eating a diet containing high amounts of whole grains may be a reduced risk of liver cancer, a new U.S. study suggests. 

“Consumption of whole grains and dietary fiber, especially cereal fiber, have been associated with lower risk of obesity, type 2 diabetes, and nonalcoholic fatty liver disease, which are known predisposing factors for (liver cancer),” Zhang said. “Besides improving insulin sensitivity, metabolic regulation, and decreasing systemic inflammation, intake of whole grains and dietary fiber may improve gut integrity, and alter gut microbiota composition, thereby leading to increased production of microbiota-related metabolites including short-chain fatty acids, particularly butyrate.” 

Read more: https://in.reuters.com/article/us-health-grains-liver-cancer/whole-grains-might-help-ward-off-liver-cancer-idINKCN1QA2BE

Original Investigation 

JAMA Network OpenFebruary 21, 2019
Association of Intake of Whole Grains and Dietary Fiber With Risk of Hepatocellular Carcinoma in US Adults 
Wanshui Yang, PhD1,2; Yanan Ma, PhD2,3; Yue Liu, MD2,4; et al Stephanie A. Smith-Warner, PhD5,6; Tracey G. Simon, MD7,8,9; Dawn Q. Chong, MD10; Qibin Qi, PhD11; Jeffrey A. Meyerhardt, MD, MPH12; Edward L. Giovannucci, MD, ScD2,5,6; Andrew T. Chan, MD, MPH2,8,9; Xuehong Zhang, MD, ScD2 Author Affiliations JAMA Oncol.

Published online February 21, 2019.
doi:10.1001/jamaoncol.2018.7159

Key Points
Question Is high intake of whole grains and dietary fiber associated with lower risk of developing hepatocellular carcinoma (HCC)?

Findings In this cohort study of 125 455 participants in the United States, including 141 patients with HCC, with an average follow-up of 24.2 years, increased intake of whole grains was associated with a reduced risk of HCC. A nonsignificant inverse HCC association was observed for total bran but not for germ; increased intake of cereal fiber but not fruit or vegetable fiber was associated with a nonsignificant lower risk of HCC.

Meaning Increased intake of whole grains and possibly cereal fiber and bran could be associated with reduced risk of HCC among US adults.

Abstract
Importance Increased intake of whole grain and dietary fiber has been associated with lower risk of insulin resistance, hyperinsulinemia, and inflammation, which are known predisposing factors for hepatocellular carcinoma (HCC). Therefore, we hypothesized that long-term intake of whole grains and dietary fiber may be associated with lower risk of HCC.

Objective To assess the associations of whole grain and dietary fiber intake with the risk of HCC.

Design, Setting, and Participants Cohort study of the intake of whole grains, their subcomponents (bran and germ), and dietary fiber (cereal, fruit, and vegetable) in 125 455 participants from 2 cohorts from the Nurses’ Health Study and the Health Professionals Follow-up Study.

Exposures Intake of whole grains, their subcomponents (bran and germ), and dietary fiber (cereal, fruit, and vegetable) were collected and updated almost every 4 years using validated food frequency questionnaires.

Main Outcomes and Measures Multivariable hazard ratios (HRs) and 95% CIs were estimated using Cox proportional hazards regression model after adjusting for most known HCC risk factors.

Results After an average follow-up of 24.2 years, we identified 141 patients with HCC among 125 455 participants (77 241 women and 48 214 men (mean [SD] age, 63.4 [10.7] years). Increased whole grain intake was significantly associated with lower risk of HCC (the highest vs lowest tertile intake: HR, 0.63; 95% CI, 0.41-0.96; P = .04 for trend). A nonsignificant inverse HCC association was observed for total bran (HR, 0.70; 95% CI, 0.46-1.07; P = .11 for trend), but not for germ. Increased intake of cereal fiber (HR, 0.68; 95% CI, 0.45-1.03; P = .07 for trend), but not fruit or vegetable fiber, was associated with a nonsignificant reduced risk of HCC.

Conclusions and Relevance Increased intake of whole grains and possibly cereal fiber and bran could be associated with reduced risk of HCC among adults in the United States. Future studies that carefully consider hepatitis B and C virus infections are needed to replicate our findings, to examine these associations in other racial/ethnic or high-risk populations, and to elucidate the underlying mechanisms.
https://jamanetwork.com/journals/jamanetworkopen