Open AccessFiber-rich diet with brown rice improves endothelial function in type 2 diabetes mellitus: A randomized controlled trial
Author(s) -
Keiko Kondo,
Katsutaro Morino,
Yoshihiko Nishio,
Atsushi Ishikado,
Hisatomi Arima,
Keiko Nakao,
Fumiyuki Nakagawa,
Fumio Nikami,
Osamu Sato,
Koji Nemoto,
Makoto Suwa,
Marcelo Hide Matsumoto,
Katsuyuki Miura,
Tomoki Makino,
Satoshi Ugi,
Hiroshi Maegawa
Publication year - 2017
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0179869
Subject(s) - brown rice , medicine , type 2 diabetes , postprandial , type 2 diabetes mellitus , reactive hyperemia , diabetes mellitus , endocrinology , endothelial dysfunction , vasodilation , biology , food science
Background & Aims A fiber-rich diet has a cardioprotective effect, but the mechanism for this remains unclear. We hypothesized that a fiber-rich diet with brown rice improves endothelial function in patients with type 2 diabetes mellitus. Methods Twenty-eight patients with type 2 diabetes mellitus at a single general hospital in Japan were randomly assigned to a brown rice ( n = 14) or white rice ( n = 14) diet and were followed for 8 weeks. The primary outcome was changes in endothelial function determined from flow debt repayment by reactive hyperemia using strain-gauge plethysmography in the fasting state. Secondary outcomes were changes in HbA 1c , postprandial glucose excursions, and markers of oxidative stress and inflammation. The area under the curve for glucose after ingesting 250 kcal of assigned rice was compared between baseline (T0) and at the end of the intervention (T1) to estimate glucose excursions in each group. Results Improvement in endothelial function, assessed by fasting flow debt repayment (20.4% vs . −5.8%, p = 0.004), was significantly greater in the brown rice diet group than the white rice diet group, although the between-group difference in change of fiber intake was small (5.6 g/day vs . −1.2 g/day, p<0.0001). Changes in total, HDL-, and LDL-cholesterol, and urine 8-isoprostane levels did not differ between the two groups. The high-sensitivity C-reactive protein level tended to improve in the brown rice diet group compared with the white rice diet group (0.01 μg/L vs . −0.04 μg/L, p = 0.063). The area under the curve for glucose was subtly but consistently lower in the brown rice diet group (T0: 21.4 mmol/L*h vs . 24.0 mmol/L*h, p = 0.043, T1: 20.4 mmol/L*h vs . 23.3 mmol/L*h, p = 0.046) without changes in HbA 1c . Conclusions Intervention with a fiber-rich diet with brown rice effectively improved endothelial function, without changes in HbA1c levels, possibly through reducing glucose excursions.