Whole grain consumption in Japan, with a focus on brown rice: Current status and challenges from a public health and health economic perspective

Abstract

Whole grains, which retain the bran and germ layers, are rich in nutrients and more nourishing than refined grains, with a globally acclaimed potential to prevent non-communicable diseases. The World Health Organization and Food and Agriculture Organization of the United Nations recommend whole grains as part of a healthy and sustainable diet, and several countries explicitly include them in their national dietary guidelines. In contrast, Japan lacks a clear definition or intake recommendation for whole grains and consumption levels remain notably low. This article reviews international evidence on the public health and health economic impact of whole-grain consumption, focusing on brown rice, a representative whole grain in Japan. Although brown rice intake has been associated with a reduced risk of type 2 diabetes, its consumption remains limited in Japan owing to barriers such as taste preferences, preparation efforts, and limited availability. Partial substitution of white rice with brown rice may help prevent type 2 diabetes and reduce national healthcare expenditure. Promoting the intake of whole grains, including brown rice, through multifaceted strategies, such as enhanced nutrition and health education, collaboration with food industry stakeholders, and incorporation into school and workplace meals, may support long-term improvements in population health and the containment of social security costs.