Rice Bran: A Comprehensive Review of Phytochemicals and Bioactive Components With Therapeutic Potential and Health Benefits

Rice bran is a by-product of paddy rice milling that has emerged as a versatile source of nutritional, preventive, and therapeutic compounds. Rich with diverse bioactive elements, rice bran serves as a nontraditional functional food ingredient with health promoting attributes. The nutritional profile of rice bran compared to those of other cereal grains is inclusive of energy-providing carbohydrates, essential vitamins and minerals, and amino and fatty acids, as well as unique phytochemicals. The composition of rice bran consists of an array of phytosterols, prebiotics, tocotrienols, tocopherols, flavonoids, and phenolic compounds that contribute antioxidant, anti-inflammatory, and antimicrobial activities. A unique rice bran compound is γ-oryzanol, which is widely recognized for supporting the immune system, regulating blood lipids, and protecting against some types of cancer. In this review we have summarized the multifaceted potential of rice bran for reducing diarrhea and controlling diabetes and cardiometabolic disease, as well as preventing or controlling progression of cancer. Rice bran-mediated regulation of bowel function through prebiotics and soluble and insoluble fiber acts synergistically in lowering gut inflammation through microbiota and regulating the metabolism of lipids and proteins that are important for health. The capacity of rice bran to enhance nutritional status in connection with the prevention and management of chronic diseases merits greater attention in the food product marketplace. In this comprehensive overview of rice bran as a functional food for human health, we have also included its medical food potential for holistic well-being, health promotion, and disease prevention.