Kugako Sugimoto, NOST Tokyo
Originally published on the site of NL Agency.
Summary
A research team of the Graduate School of Medicine of the University of Ryukyu reported in Diabetes (July 23, 2012) that brown rice and its component gamma-oryzanol suppressed craving for high-fat foods. Eating brown rice does not have serious side effects or a negative influence on the brain compared to some appetite depressing drugs. The researchers hope a traditional Japanese food can support the health and wellness of people with obesity concerns.
Details
Introduction
Recently in Japan, being fat is an issue related to a metabolic syndrome, a combination of medical disorders that enhances the risk of developing cardiovascular disease and diabetes. Eating fatty foods such as hamburgers, pizza, and ice cream rather than traditional Japanese food is considered to be one of the reasons for increasing obesity in Japan. Professor Hiroaki Masuzaki and his research team at the Graduate School of Medicine, University of Ryukyu reported that brown rice rich in gamma-oryzanol decreased cravings of fatty foods and lead to losing weight in the mouse experiments. Eating brown rice might stimulate the appetite for healthy food instead of fatty food, which would be a new strategy for the prevention and treatment for obesity and diabetes.
Mechanism
Eating fatty foods increases endoplasmic reticulum (ER) stress in the hypothalamus. Increased ER stress stimulates people to eat fatty foods, which creates a vicious cycle of unhealthy and high calory eating style. Gamma-oryzanol abundant in brown rice restrains ER stress and shifts the appetite for fatty foods to ordinary/regular (not-fatty foods) meals.
Research I (brown rice, food level)
Mice were fed with brown rice, or white rice, or no rice. At the same time, those mice were fed with fatty foods and ordinary foods. Mice fed with brown rice tended to eat ordinary foods. On the other hand, mice fed with white rice or no rice did not show such tendency and they kept eating fatty foods. Mice that were fed with brown rice gained less weight than the mice fed with white rice or no rice. Eating brown rice changed the preference of foods and consequently restrained weight gain.
Research II (gamma-oryzanol, chemical level)
20 – 30 μg of gamma-oryzanol (extraction from brown rice) per gram of a mouse weight was applied to diet-induced-obesity mice. Expression of response genes for ER stress such as Chop, ERdj4, and Xbp1 were decreased. This means ER stress was suppressed by gamma-oryzanol.
Conclusion
Taking medicine to lose weight is probably an easy way in comparison with doing exercise and eating less. However, developing and producing such drugs is quite expensive. In addition, some appetite depressants did not work effectively and had side effects on the heart and nerve system. On the other hand, eating brown rice seems very healthy and does not cost much. On top of that, brown rice tastes good and gives satisfaction to the stomach. Of course, how much to eat needs consideration. If eating tasty foods makes you thinner, that would be a dream for dieters.
Source
1) Press release: University of Ryukyu
2) Paper: Chisayo Kozuka, Kouichi Yabiku, Sumito Sunagawa, Rei Ueda, Shin-ichiro Taira, Hiroyuki Ohshiro, Tomomi Ikema, Ken Yamakawa, Moritake Higa, Hideaki Tanaka, Chitoshi Takayama, Masayuki Matsushita, Seiichi Oyadomari, Michio Shimabukuro, Hiroaki Masuzaki (2012): Brown rice and its component γ-oryzanol, attenuate the preference for high-fat diet by decreasing hypothalamic endoplasmic reticulum stress in mice: Diabetes published online before print July 23, 2012, doi: 10.2337/db11-1767
3) Endoplasmic reticulum stress: Biochemistry, School of Natural Science. National University of Ireland
4) Brown rice: Wikipedia
