Rice fibre, resistant starch and blood sugar effects
What it found
Polished white rice is over 90% starch with only trace fibre, leading to rapid digestion and a high glycaemic index.
Adding more fibre and resistant starch to rice could lower its effect on blood sugar.
What they found
Studies in people
Blood sugar and disease risk
Eating too many foods that raise blood sugar quickly is linked to higher risks of type-2 diabetes, heart disease and some cancers. In South East Asia alone, the number of people with diabetes is predicted to reach 120 million by 2030.
Other findings
Fibre lost in polishing
Polishing removes the bran and embryo from rice, taking away most of the vitamins, minerals and dietary fibre. White rice ends up as over 90% starch with only trace amounts of fibre, so it is digested very quickly.
Fibre amount in rice
Dietary fibre makes up only about 0.5 to 2% of polished white rice, compared to around 6% in unpolished rice. Rice fibre is different from wheat fibre because it contains about 25% pectin, which is only found in trace amounts in other cereals.
Resistant starch types
Resistant starch escapes digestion in the small intestine and is fermented by gut bacteria in the colon. The authors describe five types, including starch protected by intact cell walls, starch formed when cooked rice is cooled, and starch altered by chemicals or fats.
Texture and starch trade-off
Different types of rice have glycaemic index values ranging from 48 to 92, with an average of 64. Higher amylose starch lowers the glycaemic index but makes the rice harder, while people in South East Asia generally prefer soft textured rice.
What the authors conclude
- They are working to identify natural variation in the fibre content and composition of white rice in their laboratories.
- Their aim is to combine high-fibre rice types with moderate levels of resistant starch to create healthier rice lines.
- They want these new rice varieties to keep the good cooking quality and soft texture that consumers expect.
How it was done
White rice is the main calorie source in South East Asia but loses most of its vitamins, minerals and fibre during polishing. Eating too many foods that raise blood sugar quickly is linked to rising rates of type-2 diabetes, heart disease and some cancers in the region.
The authors reviewed existing research on rice fibre, resistant starch and blood sugar responses. They also described their own ongoing laboratory work to find natural differences in fibre content among rice varieties. Their goal is to breed new rice lines that combine more fibre with moderate resistant starch while keeping the soft texture people prefer.
What it can’t tell you
- This paper mostly reviews existing evidence rather than testing a new treatment in people or animals.
- Observational links between eating white rice and type-2 diabetes cannot prove that one causes the other.
- Scientists do not yet fully understand exactly how dietary fibre slows down digestion and nutrient absorption.
Who paid
- Authors work at
- Grain Quality and Nutrition Centre, IRRI
The paper
- Title
- Improving Rice Dietary Fibre Content and Composition for Human Health
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Lovegrove A, Kosik O, Bandonill E, et al (2019). Improving Rice Dietary Fibre Content and Composition for Human Health. Journal of nutritional science and vitaminology. doi:10.3177/jnsv.65.S48Free full textPubMed 31619645DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error