A comparison of the effects of resistant starch types on glycemic response in individuals with type 2 diabetes or prediabetes: A systematic review and meta-analysis

Abstract

BackgroundType 2 diabetes (T2D) diagnoses are predicted to reach 643 million by 2030, increasing incidences of cardiovascular disease and other comorbidities. Rapidly digestible starch elevates postprandial glycemia and impinges glycemic homeostasis, elevating the risk of developing T2D. Starch can escape digestion by endogenous enzymes in the small intestine when protected by intact plant cell walls (resistant starch type 1), when there is a high concentration of amylose (resistant starch type 2) and when the molecule undergoes retrogradation (resistant starch type 3) or chemical modification (resistant starch type 4). Dietary interventions using resistant starch may improve glucose metabolism and insulin sensitivity. However, few studies have explored the differential effects of resistant starch type. This systematic review and meta-analysis aims to compare the effects of the resistant starch from intact plant cell structures (resistant starch type 1) and resistant starch from modified starch molecules (resistant starch types 2–5) on fasting and postprandial glycemia in subjects with T2D and prediabetes.MethodsDatabases (PubMed, SCOPUS, Ovid MEDLINE, Cochrane, and Web of Science) were systematically searched for randomized controlled trials. Standard mean difference (SMD) with 95% confidence intervals (CI) were determined using random-effects models. Sub-group analyses were conducted between subjects with T2D versus prediabetes and types of resistant starch.ResultsThe search identified 36 randomized controlled trials (n = 982), 31 of which could be included in the meta-analysis. Resistant starch type 1 and type 2 lowered acute postprandial blood glucose [SMD (95% CI) = -0.54 (–1.0, –0.07)] and [–0.96 (–1.61, –0.31)]. Resistant starch type 2 improved acute postprandial insulin response [–0.71 (–1.31, –0.11)]. In chronic studies, resistant starch type 1 and 2 lowered postprandial glucose [–0.38 (–0.73, –0.02), –0.29 (–0.53, –0.04), respectively] and resistant starch type 2 intake improved fasting glucose [–0.39 (–0.66, –0.13)] and insulin [–0.40 (–0.60, –0.21)].ConclusionResistant starch types 1 and 2 may influence glucose homeostasis via discrete mechanisms, as they appear to influence glycemia differently. Further research into resistant starch types 3, 4, and 5 is required to elucidate their effect on glucose metabolism. The addition of resistant starch as a dietary intervention for those with T2D or prediabetes may prevent further deterioration of glycemic control.

Harnessing the power of resistant starch: a narrative review of its health impact and processing challenges

“…Nonetheless, Pugh et al, in their subgroup analyses, highlighted that significant effects on glycemic response were primarily observed with RS1 and RS2 but not with RS3. This observation can be attributed to the fact that RS1 and RS2 received more extensive research attention across the scientific literature, whereas the analysis of RS3 was based on only two studies ( 64 ). A limited number of clinical trials also focused on RS4.…”

“…Overall, the benefits of the different types of RS are likely exerted through different pathways ( 64 ), as demonstrated by the varying microbiota responses to different types of RS. For instance, after 12 weeks of consuming 12 g of RS4 daily, a significant decrease in bile acid in stools were reported compared to control ( 79 ).…”

“…Focusing on the target population, the authors noted that the acute postprandial glycemic response was significantly reduced in both prediabetics and type-2 diabetics, but the chronic response was effective only in diabetics subjects. Other metabolic markers such as glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and insulin sensitivity (HOMA-IR) remained unaffected by RS ( 64 ).…”

“…The effects of RS on health have been widely investigated in the past decades. For this review, a total of 14 meta-analyses compiling data from these studies were retrieved (56)(57)(58)(59)(60)(61)(62)(63)(64)(65)(66)(67)(68)(69)(70). These meta-analyses vary in their focus on different types of RS and target populations.…”

Nutrition at the Intersection between Gut Microbiota Eubiosis and Effective Management of Type 2 Diabetes

“…Furthermore, the results of a meta-analysis reported that resistant starch supplementation is associated with an improvement in blood glucose, insulinemia, insulin sensitivity, and resistance, especially in patients with diabetes and overweight or obesity [ 160 ]. More specifically, type 1 and type 2 resistant starches have been associated with improved post-prandial blood glucose, and in addition, type 2 resistant starch has been associated with improved post-prandial insulin response and fasting blood glucose [ 162 ]. The use of type 3 resistant starch for 3 to 11 weeks resulted in a reduction in fasting blood glucose, triglycerides, and total cholesterol in a diabetic mice model [ 163 ].…”