Efficacy of continuous ingestion of dewaxed brown rice on the cognitive functions of the residents of elderly welfare facilities: A pilot test using crossover trial.

Compared with regular brown rice, dewaxed brown rice (DBR), prepared by excluding only the wax layer in the outermost layer of brown rice using a new rice milling technique, has improved water absorbency, digestibility, and taste. Dewaxed brown rice has a nutritional value close to that of brown rice and contains a large amount of lipopolysaccharides (LPS), which are known to improve the cognitive function of mice. In this study, we examined the effect of continuous DBR ingestion on the cognitive function of elderly people. A crossover comparison test was performed, in which elderly people who moved into an elderly welfare facility were divided into two groups and ingested DBR or polished white rice for three meals a day for 6 months, followed by a change in test meals for the next 6 months. Cognitive function was assessed using Revised Hasegawa's Dementia Scale (HDS-R) before starting the test and 6 months after ingesting each test meal. No subjects withdrew or discontinued DBR intake during the study period, and all subjects continued the test for 6 months. In subjects with low cognitive function (defined as subjects with HDS-R total score of ≥1 but <10 at the start of the study), there was a significant association between continuous DBR ingestion and cognitive function improvement (increase in total HDS-R score). Our findings suggest that the long-term DBR ingestion as a staple food could be useful for preventing cognitive decline in elderly; it offers an easily implemented option as a daily diet for preventing cognitive decline.

Effect of Continuous Dewaxed Brown Rice Ingestion on the Cognitive Function of Elderly Individuals.

Dewaxed brown rice (DBR), which is prepared by removing only the outermost wax layer of brown rice using a new rice milling technique, has improved water absorbency, digestibility, and taste compared to regular brown rice. DBR has a nutritional value close to that of brown rice, including a rich amount of lipopolysaccharides that are known to improve cognitive function in mice. This study thus aimed to verify the influence of continuous DBR ingestion on cognitive function among elderly individuals. The present study employed a crossover comparison design using the Revised Hasegawa Dementia Scale to assess cognitive function. Our findings confirmed that long-term DBR ingestion contributed to the prevention and reduction of overall cognitive decline, especially among elderly individuals with low cognitive function. Thus, DBR has the potential to be a useful staple food that maintains brain homeostasis among elderly individuals.

Dewaxed Brown Rice Feed Improves Fatty Liver in Obese and Diabetic Model Mice.

BACKGROUND/AIM: Dewaxed brown rice has macrophage activation ability via TLR4 and contains a high amount of lipopolysaccharides (LPS). It is expected that dewaxed brown rice can help prevent lifestyle diseases. In this study, the anti-obesity effect of dewaxed brown rice was investigated using obese and diabetic model mice. MATERIALS AND METHODS: Dewaxed brown rice and white rice were polished and powdered by Toyo Rice Co. Diet pellets were prepared (AIN-93) with 50% dewaxed brown rice or white rice powder and fed to type II diabetic model KK-Ay mice for 10 weeks. Weight and fasting blood glucose were measured every week, and whole blood and liver was collected on the final day for the evaluation of biochemical data. RESULTS: A 20% reduction in body weight was found in the dewaxed brown rice feed and white rice feed groups compared to the normal feed group. Fasting blood glucose increased in the normal-diet group, but on the other hand, the blood glucose in the white rice and the dewaxed brown rice feed group was almost constant. Dewaxed brown rice feed group of plasma ALT and AST, liver TG and T-CHO were significantly lower than that of the control and the white rice feed group. CONCLUSION: Dewaxed brown rice feed has an anti-obesity effect to suppress increasing body weight, fasting blood glucose, and an effect of suppressing fatty liver.

Improvement Effect of Dewaxed Brown Rice on Constipation in Antibiotic-treated Mice.

BACKGROUND/AIM: A decrease in gastrointestinal motility causing weakened lipopolysaccharide (LPS) - toll-like receptor (TLR)4 signaling along with a decline in the number of enteric bacteria is known to be a cause of constipation due to the administration of antibiotics. A new type of brown rice with its wax layer removed, resulting in quick-cooking and tasty product, contains 100-times more LPS than polished white rice. In this study, the improvement effect on constipation due to intake of dewaxed brown rice was examined. MATERIALS AND METHODS: Dewaxed brown rice was prepared at Toyo Rice from brown rice. Mice were given powdered feed to which powdered rice containing 0-50% of dewaxed brown rice was added. Antibiotics were administered for 10 or 27 days in drinking water containing vancomycin, metronidazole and neomycin. LPS, used as a control, was freely provided in drinking water. The defecation frequency, stool weight per hour and body weight were determined on the last day. RESULTS: Although the 10-day administration of antibiotics reduced the stool weight per hour to half, the dewaxed brown rice and LPS groups showed a trend towards improvement at a level comparable to the group receiving no antibiotics. The body weight significantly decreased after the 27-day administration of antibiotics but was improved in the 50% dewaxed brown rice group at a level comparable to the group receiving no antibiotics. Though the defecation frequency and wet and dry stool weights per hour were reduced by as much as 50% in the group receiving antibiotics, a significant improvement in constipation was observed in the 50% dewaxed brown rice group. CONCLUSION: As the improvement effect of dewaxed brown rice on body weight loss and constipation caused by the long-term administration of antibiotics has been confirmed in animal experimentation, the introduction of dewaxed brown rice as a staple food to patients under long-term antibiotic treatment may improve constipation.

Dewaxed Brown Rice Contains a Significant Amount of Lipopolysaccharide Pointing to Macrophage Activation via TLRs.

BACKGROUND/AIM: Oral ingestion of lipopolysaccharide (LPS) has been shown to be effective in diseases' prevention. Brown rice contains large amounts of LPS not actively consumed because of bad taste. Recently, a new type of brown rice with its wax layer removed has been produced. In this report, we measured the LPS content of this dewaxed rice and evaluated the function of innate immune activation on macrophages. MATERIALS AND METHODS: Dewaxed brown rice and polished rice were prepared using the Saika-style rice polishing process. LPS content extracted using hot water from this sample was evaluated by the Limulus reaction and the activation of macrophage RAW246.7 cells was evaluated by nitric oxide (NO) production. In addition, toll-like receptors (TLRs) 2-, 4- and 9-induced human embryonic kidney (HEK) 293 cells were used for the confirmation of the activated pathway. RESULTS: Mean LPS content in the 15 types of dewaxed brown rice was found to be 6.4±2.6 µg/g, while that of brown rice was 10.9±4.3 µg/g. The extract of dewaxed brown rice induced significant amounts of NO by RAW246.7 cells, while production was reduced to 1/6 by adding polymyxin B. The macrophage activating effect of dewaxed brown rice was 79- and 51-times higher than that of polished rice in TLR4- and 2-induced HEK 293 cells. CONCLUSION: LPS content in dewaxed brown rice was found to be able to activate macrophages. This rice activated macrophages mainly via the TLR4 and, to a lesser extent, TLR2 pathways. It is suggested that dewaxed brown rice can be considered effective in allergy and cancer prevention.