A new study published in The American Journal of Clinical Nutrition has reported that whole-grain rice significantly reduced postprandial blood glucose response compared to refined white.
A postprandial glucose test is a blood glucose test that determines the amount of a glucose, in the blood after a meal.
Musa Veloso and associates performed a meta-analysis to compare the postprandial blood glucose response of whole-grain with refined wheat, rice, or rye while controlling for the food delivery matrix and the processing of the grain (e.g., grinding, germination).
The investigators selected 20 publications from 11 electronic databases which compared the effects of whole-grain wheat, rice or rye with each grain’s refined counterpart on postprandial blood glucose area under the curve (AUC).
In a similar study, Medical Dialogues has earlier reported that intake of whole grain such as rye, oats or wheat, can help in the prevention of type 2 diabetes.
The key findings of the analysis are:
- The consumption of ground (wholemeal) wheat, compared with white wheat, was not associated with a significant reduction in blood glucose AUC (-6.7 mmol/L ⋅ min; -25.1 to 11.7 mmol/L.
- The consumption of wholemeal rye, compared with endosperm rye, was not associated with a significant reduction in blood glucose AUC (-5.5 mmol/L ⋅ min; -24.8 to 13.8 mmol/L ⋅ min).
- The consumption of intact (whole-grain) rice, compared with white rice, was associated with a significant reduction in blood glucose AUC (-40.5 mmol/L ⋅ min; -59.6 to -21.3 mmol/L ⋅ min).
According to the authors, whole grains contain more nutritional value and are important in preserving glycaemic benefit as the amylase access to the starch is hindered by the encapsulating cell wall, but once the integrity of the whole-grain is lost by grinding it into a flour this hindrance is likely lost
The study concluded that compared with white rice, whole-grain rice significantly attenuates the postprandial blood glucose response.
“In most of the studies on wheat and rye, the postprandial blood glucose responses to foods formulated with wholemeal compared with refined flours were compared and whether reductions in the blood glucose AUC can be achieved with whole-grain (as opposed to wholemeal) wheat and rye requires further investigation, ”write the authors.
For full information log on to 10.1093/ajcn/nqy112