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NutrInsight • Slow-release carbohydrates: Growing evidence on metabolic responses and public health interest

2.3 How does SDS modulate the glycemic response?

This double isotopic labeling technique has been used by some research laboratories (Human Nutrition
Research Center of Lyon - France; University of Montréal - Canada; University of Groningen - Netherlands) to
study the metabolic fate of carbohydrates in human subjects according to the SDS content of cereal products.
These studies were conducted over the 4 h 30 min or 6 h after ingestion to investigate also the influence of SDS
on the late postprandial phase.

SDS is slowly absorbed and released into the bloodstream

Three randomized controlled clinical trials were conducted in humans using cereal products with either a
high SDS content or nearly no SDS due to different manufacturing process conditions (high SDS biscuits vs.
extruded cereals with nearly no SDS). The cereal products were consumed as part of breakfasts matched for
nutritional composition so that the only difference between the meals was the SDS content of the cereal foods.
It has been shown in healthy males that a high SDS content significantly reduces the appearance of exogenous
glucose (RaE) in the early part of the morning and extends its release into the later part of the morning
[Vinoy et al., 2013]. Significant differences between RaE were also observed in healthy females (see Figure 6)
[Péronnet et al., 2015], as well as in normo-glycemic overweight subjects (males and females) in a study
conducted as part of the EUROSTARCH European research project [Nazare et al., 2010].

Eelderink et al. investigated the effect of different starch digestibility profiles between pasta and bread
measured using a modified SDS method. The content of what is named SDS was medium i.e. 6.1 g/100 g in
bread vs. 10.6 g/ 100 g in pasta. The cereal products were consumed by nine healthy male subjects as part of
a meal. Significant differences in RaE kinetics between pasta and bread meals were observed [Eelderink et al.,
2012].

It can be concluded that in starchy foods, slow starch digestibility (as characterized in vitro by the SDS method)
results in a slow release of carbohydrates from the ingested food into the blood. This provides confirmation in
humans of the relevance of in vitro SDS measurements.

RaE (mg/kg/min) 6* Lo-SDS
Hi-SDS 1
4 Hi-SDS 2
Hi-SDS 3

2

0 60 120 180 240
0 Time (min)

Figure 6: Kinetics of the rate of appearance of exogenous glucose (RaE) following ingestion of the three varieties of biscuits
high in Slowly Digestible Starch (SDS) (Hi-SDS 1: ; Hi-SDS 2: ; Hi-SDS 3: ) and of extruded cereals with nearly
no SDS (Lo-SDS: ) as part of a breakfast (mean ± SD, n=16 except for one of the three high SDS biscuits, for which n=15).
* P<0.05: significantly different from the high SDS products. Data have been pooled to compute the average values of the
three high SDS biscuits tested, as the differences between these products were not significant.
Source: Péronnet et al., 2015

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