Unveiling the health potential of Japonica rice: Bioactive lipids and glycemic insights for better nutrition

The relationship between dietary lipids and health is crucial for managing chronic diseases such as type 2 diabetes. This study evaluates the glycemic index (GI) and lipid composition of 56 japonica rice cultivars, focusing on their potential as functional foods to support metabolic health.

The objective is to investigate lipid diversity, nutritional indices, and glycemic properties of japonica rice cultivars, identifying bioactive lipids that promote health and prevent metabolic disorders. Using untargeted lipidomics with LC/MS, we profiled lipids. In-vitro GI assays were performed on pigmented japonica (red, black, brown, green) and indica (brown, white, parboiled) rice varieties, following the standardized assay protocol with the GOPOD kit.

We identified 198 lipid metabolites across five lipid classes. Bioactive lipids such as Fatty Acid Esters of Hydroxy Fatty Acids and N-acyl-lysophosphatidylethanolamines, known for their anti-diabetic and anti-inflammatory effects, were discovered. Nutritional assessments showed that black and green japonica rice had a higher health promotion index and lower index of atherogenicity, suggesting benefits for reducing cholesterol and improving cardiovascular health. The polyunsaturated to saturated fatty acid ratio in green and black rice (1.49 and 0.96 respectively) supports its potential for lowering cardiac disease risk. GI analysis showed that black japonica rice had the lowest GI (60), while white indica rice had a significantly higher GI (77), highlighting the role of pigmentation and regional differences in rice.

This research is relevant to the AOCS Health and Nutrition Division by providing new insights into bioactive lipids and their role in metabolic health. Linking lipidomics and glycemic properties, the study supports the development of functional foods aimed at reducing the risk of type 2 diabetes and cardiovascular diseases, with practical applications for nutritionists, food scientists, and health professionals.