Whole grains, dietary fiber, could prevent liver disease

Whole grains and dietary fiber could be associated with a lower risk of liver cancer, according to a new study published in JAMA Oncology.  

Co-authors Wanshui Yang, PhD, and Xuehong Zhang, MD, ScD, of Brigham and Women’s Hospital and Harvard Medical School in Boston, Massachusetts, and their team of researchers looked at 125,455 participants from two cohorts of the Nurses’ Health Study and the Health Professionals Follow-up Study, including 141 patients with hepatocellular carcinoma (HCC), the most common primary liver cancer. The study found increased intake of whole grains was associated with a reduced risk for HCC, according to the abstract.

A higher intake of whole grains and dietary fiber has been previously associated with lower risk of insulin resistance, hyperinsulinemia, and inflammation, researchers say, which are known risk factors for developing HCC. The researchers set out to assess the associations of whole grain and fiber intake with the risk of HCC by examining consumption of whole grains and their subcomponents bran and germ, as well as dietary fiber from cereal, fruit, and vegetables. Intake was collected and updated almost every four years, according to the study, using validated food frequency questionnaires.

After an average follow-up of about 24 years, researchers found those participants in the highest tertiles of whole grain intake and dietary fiber were slightly older, had a lower body mass index (BMI), engaged in more physical activity, consumed less alcohol, were less likely to be smokers, and tended to have a higher intake of fruits, vegetables, total folate, multivitamin, and dietary fiber, but less fat, when compared with participants in the lowest tertiles. Higher whole grain intake was significantly associated with lower HCC risk, and researchers found a significant inverse association between total bran intake and HCC. Researchers did not find any significant associations of total fiber intake, fruit, or vegetable intake with the risk of HCC.

The researchers concluded 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, they say, to examine these associations in other racial, ethnic, or high-risk populations, and to elucidate the underlying mechanisms.