Konjac glucomannan and blood fats after rice gruel
What it found
In 13 Japanese men without diabetes or dyslipidemia, rice gruel with 0.8% konjac glucomannan led to lower blood triglyceride levels after eating, along with higher levels of two fat-processing proteins at 120 minutes.
The changes were small.
What they found
Studies in people
Triglycerides after eating
In the 0.8% group, blood triglyceride levels were significantly lower at 30, 60 and 120 minutes than at the start. The 0% and 0.4% groups showed no significant change.
Free fatty acids
Free fatty acid levels fell significantly at 30, 60 and 120 minutes after all three types of gruel, with no significant differences between the groups.
LPL and GPIHBP1
In the 0% and 0.4% groups, levels of LPL and GPIHBP1 fell significantly after eating. In the 0.8% group, both rose significantly at 120 minutes compared with the start.
HTGL levels
HTGL fell significantly after eating in the 0% and 0.4% groups. In the 0.8% group, HTGL levels stayed about the same over the 120 minutes.
Fasting FFA and HTGL link
When the authors combined the baseline data from all three groups, they found a significant negative correlation between fasting free fatty acid levels and HTGL levels.
What the authors conclude
“Supplementation of rice gruel with KGM powder can lead to TG reduction accompanied by LPL and GPIHBP1 elevation and HTGL stabilization, thereby attenuating lipid metabolism.”
Also in their conclusions
- They say their results reveal new pleiotropic effects of konjac glucomannan.
- They conclude that adding konjac glucomannan powder to rice gruel can lead to triglyceride reduction, accompanied by LPL and GPIHBP1 elevation and HTGL stabilization, thereby attenuating lipid metabolism.
- They state that further study is needed to elucidate the regulatory mechanism underlying these effects.
How it was done
The authors had already shown that konjac glucomannan in rice gruel blunts the rise in blood sugar and insulin after a meal. They wanted to see whether it also affects blood fats and the proteins that process them.
Thirteen middle-aged Japanese men without diabetes, dyslipidemia or gut disease ate rice gruel with no konjac glucomannan, 0.4% or 0.8% konjac glucomannan, one type each Sunday for 3 weeks, in a double-blind randomised crossover trial. Blood was taken before the meal and at 30, 60 and 120 minutes after.
What it can’t tell you
- The study was small, with only 13 men, and did not control what they ate at home during the 3 weeks.
- It only looked at one meal, so it cannot show what happens with longer-term konjac glucomannan use.
- The authors did not work out the mechanism behind the changes in LPL, GPIHBP1 and HTGL.
Who paid
- Funding
- Funded by scientific research from the Ministry of Education, Culture, Sports Science and Technology of Japan; CSRD VA (from the PubMed record).
- Conflicts
- The authors declare that they have no competing interest.
- Authors work at
- Gunma University Graduate School of Medicine, Japan; Gunma University Hospital, Japan; Gunma University, Japan
The paper
- Title
- Konjac Glucomannan Attenuated Triglyceride Metabolism during Rice Gruel Tolerance Test
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Nagasawa T, Kimura T, Yoshida A, et al (2021). Konjac Glucomannan Attenuated Triglyceride Metabolism during Rice Gruel Tolerance Test. Nutrients. doi:10.3390/nu13072191Free full textPubMed 34202167DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error