Ancient Grains as Functional Foods: Integrating Traditional Knowledge with Contemporary Nutritional Science

Ancient grains, including wild rice, millet, fonio, teff, quinoa, amaranth, and sorghum, are re-emerging as vital components of modern diets due to their dense nutritional profiles and diverse health-promoting bioactive compounds. Rich in high-quality proteins, dietary fiber, essential micronutrients, and a broad spectrum of bioactive compounds such as phenolic acids, flavonoids, carotenoids, phytosterols, and betalains, these grains exhibit antioxidant, anti-inflammatory, antidiabetic, cardioprotective, and immunomodulatory properties. Their health-promoting effects are underpinned by multiple interconnected mechanisms, including the reduction in oxidative stress, modulation of inflammatory pathways, regulation of glucose and lipid metabolism, support for mitochondrial function, and enhancement of gut microbiota composition. This review provides a comprehensive synthesis of the essential nutrients, phytochemicals, and functional properties of ancient grains, with particular emphasis on the nutritional and molecular mechanisms through which they contribute to the prevention and management of chronic diseases such as cardiovascular disease, type 2 diabetes, obesity, and metabolic syndrome. Additionally, it highlights the growing application of ancient grains in functional foods and nutrition-sensitive dietary strategies, alongside the technological, agronomic, and consumer-related challenges limiting their broader adoption. Future research priorities include well-designed human clinical trials, standardization of compositional data, innovations in processing for nutrient retention, and sustainable cultivation to fully harness the health, environmental, and cultural benefits of ancient grains within global food systems.