Blood sugar lowered and diabetes prevented by consumption of high-amylose wheat bread, finds study.
The presence of a high concentration of readily digestible starch in conventional wheat-based foods is responsible for increased postprandial blood sugar and may lead to the development of type 2 diabetes. Now, a recent study in The Journal of Nutrition has found that consumption of bread made from high-amylose wheat (HAW) enriched in resistant starch (RS) lowers postprandial blood sugar and insulinemic response compared with bread made from conventional low-amylose wheat (LAW).
Diet-related chronic diseases such as diabetes and heart disease are on the rise in both developing and developed countries and are a major cause of morbidity and mortality. The consumption of the whole grains is highly beneficial due to the presence of their dietary fibre component which includes nonstarch polysaccharides and resistant starch. However, the consumption of more whole grain, refined starches from cereals, such as wheat, rice, and corn, can increase high glycemic response.
To address this, corn and barley varieties, and food ingredients, have been developed that contain elevated RS concentrations by increasing the proportion of amylose in the starch. Amylose concentration and RS content are positively correlated. Foods made from high-amylose cereals induce a lower postprandial glycemic response in healthy individuals than foods made from conventional grains.
Damien P Belobrajdic, CSIRO Health and Biosecurity, Adelaide, Australia, and colleagues determined whether bread made from a high-amylose variety of wheat enriched in resistant starch attenuated postprandial glycemia compared with bread made from conventional low-amylose wheat (LAW)m, in this single-centre, randomized, double-blinded, crossover controlled study.
The study involved 7 consecutive weekly visits. On separate mornings, 20 healthy nondiabetic men and women (mean age 30 ± 3 y; body mass index 23 ± 0.7 kg/m2) consumed a glucose beverage or 4 different breads (each 121 g); LAW-R (refined), LAW-W (wholemeal), HAW-R, or HAW-W.
The starch contents of the LAW and HAW bread were 24% and 74% amylose, respectively. Venous blood samples were collected at regular intervals before and for 3 h after the breakfast meal to measure plasma glucose, insulin, ghrelin, and incretin hormone concentrations, and the incremental area under the curve (AUC) was calculated (mmol/L × 3 h). Satiety and cravings were also measured at 30-min intervals during the postprandial period.
Key findings of the study include:
- HAW breads had a glycemic response (AUC) that was 39% less than that achieved with conventional wheat breads (HAW 39 ± 5 mmol/L × 3 h; LAW 64 ± 5 mmol/L × 3 h).
- Insulinemic and incretin responses were 24–30% less for HAW breads than for LAW breads.
- Processing of the flour (wholemeal or refined) did not affect the glycemic, insulinemic, or incretin response.
- The HAW breads did not influence plasma ghrelin or subjective measures of satiety or cravings during the postprandial period.
“Replacing Low amylose wheat, LAW with high-amylose wheat, HAW flour may be an effective strategy for lowering postprandial glycemic and insulinemic responses to bread in healthy men and women, but further research is warranted,” concluded the authors.
To read the study in detail follow the link: https://doi.org/10.1093/jn/nxz067