Bioactive compounds of highland barley and their health benefits

Whole grains refer to grains or foods that contain all the bran, germ, and endosperm of the entire grain seeds with the original proportions. According to the Dietary Guidelines for Americans 2020–2025, whole grains are recommended to constitute at least half of the total grain intake. Highland barley (HB), as a principal crop widely cultivated in the Tibetan area of China, has drawn growing attention because of its unique nutrients and abundant bioactive compounds. Whole grain HB was reported to have higher levels of β-glucans, phenolics, tocols, and phytosterols than most other grains. The objective of the paper is to give a comprehensive review of the nutrient composition and major bioactive compounds in HB with a special focus on the health benefits of the bioactive constituents. Whole grain HB and its extracts have been reported to exhibit potential health-promoting abilities including anti-cardiovascular disease, anti-obesity, anti-diabetes, gut protective, and anticarcinogenic effects owing to its unique profile of nutrients and bioactive compounds. Considering that the applications of HB as a dietary whole grain component is still limited, this review can facilitate the understanding of the values and mechanisms of HB grains in disease prevention, thus increasing the whole grain HB intake and promoting the development of HB-based health-promoting foods.