Acute effects of non-homogenised and homogenised vegetables added to rice-based meals on postprandial glycaemic responses and in vitro carbohydrate digestion.
Level 2 - randomized trial
Randomized crossover trial in human subjects
PubMed 30355395 · doi:10.1017/S0007114518002489
What was done
Sixteen healthy participants completed a randomised crossover trial comprising thirteen test sessions: two with glucose control, two with white rice alone, and nine with vegetable-rice combinations. Test meals included cooked white rice combined with cooked intact pak choi, cauliflower, or eggplant, as well as their raw or cooked homogenised forms. Postprandial glycaemic responses were monitored, alongside in vitro carbohydrate digestion and chemical analyses.
What was found
Compared with white rice alone, meals with intact cooked eggplant, pak choi, and cauliflower achieved significantly lower glycaemic index values of 67, 71, and 73, respectively. In contrast, homogenised counterparts showed no significant difference in glycaemic response compared to rice alone. Hydrolysis indexes for the intact eggplant, pak choi, and cauliflower meals were 69.6%, 83.8%, and 80.6% of the pure rice control. Cooked eggplant produced the greatest reductions in glycaemic index, 120-minute incremental area under the glucose curve, peak blood glucose, maximum amplitude of glucose excursion, hydrolysis index, and rapidly available starch.
Why it matters
This study indicates that the physical structure and texture of vegetables, not just their nutrient content, are essential for blunting the postprandial glucose spike when consumed with high-glycaemic carbohydrates like rice.
Limits
The study had a small sample size of sixteen healthy volunteers, meaning findings may not generalize directly to individuals with impaired glucose tolerance or type 2 diabetes. The abstract does not report exact baseline participant demographics, variability metrics (such as standard deviations or confidence intervals), or long-term metabolic outcomes.
Cited by
- contradicts Cooking green vegetables ruptures plant cell walls, making their carbohydrates more accessible and increasing their glycemic impact compared to raw leafy greens.