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 from Harvard Medical School and Brigham and Women’s Hospital in Boston suggests.
The analysis of data on more than 125,000 men and women followed for an average of 24 years found that those who ate the most whole grains had nearly 40 percent lower odds of developing liver cancer compared to those who ate the least. Although deadly, liver cancer is relatively rare in the U.S.
The researchers suspected that whole grains might be protective against liver cancer because grains have been found to improve a number of well-known risk factors for the disease.
Consumption of whole grains and dietary fibre, especially cereal fiber, have been associated with lower risk of obesity, type 2 diabetes, and non-alcoholic fatty liver disease, which are known predisposing factors for liver cancer. Besides improving insulin sensitivity, metabolic regulation, and decreasing inflammation, intake of whole grains and dietary fibre may improve gut integrity and alter gut microbiota composition.
About the study
To look at the impact of whole grains, the researchers examined data gathered in two long-term studies of nurses and other health professionals. Along with a host of other health measurements, the 125,455 participants filled-out detailed descriptions of their diets approximately once every four years.
When it came to whole grains, even those who ate the most consumed only about an ounce a day (33.28 g/day). The researchers divided participants into five groups based on their average intake of whole grains, as well as components of whole grain, bran and germ. They also looked at total dietary fiber from cereal grains, fruits and vegetables.
Whole grain eaters 37% less likely to develop liver cancer
After accounting for factors such as age, BMI, physical activity, smoking, type 2 diabetes, alcohol consumption and aspirin use, the researchers found that those who consumed the most whole grains were 37 percent less likely to develop liver cancer compared to those who consumed the least.
Liver cancer risk was also reduced among those who ate the most bran, but not those who had the highest germ consumption. The same was true for the highest cereal grain intake, but not for fruit and vegetable fibre.
Outside experts said that with such a small number of cancers it’s hard to have a lot of confidence in the association found by the researchers.
Moreover, those who consumed the most whole grains were also the healthiest study participants overall. They had lower BMI, engaged in more physical activity, consumed less alcohol, were less likely to be smokers, were more likely to use aspirin and tended to have higher intakes of fruits, vegetables, total folate, multivitamin and dietary vitamin, but less fat, compared to participants who took in the least.
While the study is not strong enough to spark new recommendations with respect to liver cancer and whole grains, given the overall benefits of whole grains compared to refined grains, shifting your diet away from processed grains is likely helpful to all people, including those at risk for liver cancer.
All research on this web site is the property of Leslie Beck Nutrition Consulting Inc. and is protected by copyright. Keep in mind that research on these matters continues daily and is subject to change. The information presented is not intended as a substitute for medical treatment. It is intended to provide ongoing support of your healthy lifestyle practices.