Instant rice made from white and pigmented giant embryonic rice reduces lipid levels and body weight in high fat diet-fed mice.

Problem: With the growing health problem on obesity and its associated metabolic disorders, functional foods with hypolipidemic and body fat-lowering effects are greatly needed. The effects of instant rice made from a combination of pigmented giant embryonic rice (Keunnunjami) and white rice, in comparison with those of instant non-pigmented giant embryonic brown rice and instant ordinary brown rice, on the lipid metabolism and body weight in mice under high fat diet condition were investigated.

Methods: Male C57BL/6N mice (n=48) were given experimental diets for seven weeks: normal control (NC), high fat (HF), and HF supplemented with instant normal brown rice (HF-NB), non-pigmented giant embryonic brown rice (HF-GB), and white rice with 8% Keununnjami (HF-KJ8) or 18% Keunnunjami (HF-KJ18). Their body weight gain, plasma lipid profile, adipokine level, lipid-regulating enzymes activities, and mRNA expressions of peroxisome proliferator-activated receptors (PPARs) were determined.

Results: At the end of the experimental period, the HF mice exhibited significantly higher body weight and fat, plasma triglyceride and total cholesterol levels, and atherogenic index and lower high-density lipoprotein cholesterol concentration than the NC group. However, diet supplementation of instant rice counteracted this high fat-induced body weight gain and hyperlipidemia through inhibition of lipogenesis and adipokine production and alteration of PPARs expressions.

Conclusion: The instant KJ8 and KJ18 rice showed generally similar hypolipidemic and body weight-lowering effects to instant NB and GB rice. These findings demonstrate that instant white rice with added 8% Keunnunjami may be beneficial as functional food with strong hypolipidemic and anti-obesity properties.