The findings were presented to the American Association for Cancer Research on Tuesday.  

By Lauren Wicks
Updated: April 08, 2019

Whole grain and fiber intake have long been associated with a lowered risk of insulin resistance, high blood insulin levels, and inflammation—all risk factors for hepatocellular carcinoma (HCC), the most common type of liver cancer. But it's never been clear if there were links between whole grain consumption and an actual reduced risk for developing HCC. So a group of Harvard researchers looked into it, and found significant associations between the two. Their findings were presented on Tuesday to the American Association for Cancer Research.

The study consisted of a data analysis of two large, long-term Harvard studies—the Nurse’s Study (which has followed 280,000 participants since 1976) and the Health Professionals Follow-Up Study (which has followed 51,529 men in health professions since 1986).

Researchers found 141 incidents of liver cancer among the two populations, and they also found that higher whole grain intake was strongly associated with a reduced risk for HCC.

People who consumed higher amounts of bran, germ, and whole-grain fiber were specifically associated with decreased cancer risk. This means refined grains (where the germ and bran are removed from a grain) did not contribute to a lowered cancer risk.

Learn more about whole grains from Cooking Light:

The authors noted while whole-grain fiber intake was linked to the lowered risk for HCC, fiber intake from fruits and vegetables was not. They also noted further studies need to be conducted on more diverse or high-risk populations, as The Nurse’s Study and Health Professionals Follow-Up Study cohorts studied primarily highly-educated white men and women.

The bottom line: This is the first study of its kind and more research is needed to make stronger associations. However, whole grains are full of essential nutrients like fiber, B vitamins, protein, and healthy fats, and would do ourselves a favor by consuming more of them—especially if they are replacing refined grains.