Dietary Glycemic Index and Load and the Risk of Type 2 Diabetes: Assessment of Causal Relations

Abstract

While dietary factors are important modifiable risk factors for type 2 diabetes (T2D), the causal role of carbohydrate quality in nutrition remains controversial. Dietary glycemic index (GI) and glycemic load (GL) have been examined in relation to the risk of T2D in multiple prospective cohort studies. Previous meta-analyses indicate significant relations but consideration of causality has been minimal. Here, the results of our recent meta-analyses of prospective cohort studies of 4 to 26-y follow-up are interpreted in the context of the nine Bradford-Hill criteria for causality, that is: (1) Strength of Association, (2) Consistency, (3) Specificity, (4) Temporality, (5) Biological Gradient, (6) Plausibility, (7) Experimental evidence, (8) Analogy, and (9) Coherence. These criteria necessitated referral to a body of literature wider than prospective cohort studies alone, especially in criteria 6 to 9. In this analysis, all nine of the Hill’s criteria were met for GI and GL indicating that we can be confident of a role for GI and GL as causal factors contributing to incident T2D. In addition, neither dietary fiber nor cereal fiber nor wholegrain were found to be reliable or effective surrogate measures of GI or GL. Finally, our cost–benefit analysis suggests food and nutrition advice favors lower GI or GL and would produce significant potential cost savings in national healthcare budgets. The high confidence in causal associations for incident T2D is sufficient to consider inclusion of GI and GL in food and nutrient-based recommendations.

Characterizing the Retinal Phenotype in the High-Fat Diet and Western Diet Mouse Models of Prediabetes

“…LFDs promote insulin resistance, and while most of the research has been performed in humans, these findings may have relevance to murine studies. LFD, typically considered a high carbohydrate diet, is known to promote inflammation [74][75][76]. A recent study compared ERGs in HFD fed rats, Streptozotocin (STZ) rats and type 2 diabetes (T2D) rats at 6 months to controls.…”

Sensory attributes, nutritional qualities, and glycemic indices of bread blends produced from cocoa powder flavored yellow‐fleshed cassava‐wheat composite flours

“…Starchy foods are divided into low, medium, or high GI foods in accordance to the level digestion and absorption in the system (Eleazu, 2016; Zhang & Hamaker, 2009). The common consumption of foods that exhibit a high glycemic index is related to the development of some pathologies such as type‐2 diabetes (Bhupathiraju et al., 2014; Livesey et al., 2019) and certain emergence of cancer (George et al., 2009; Zelenskiy, Thompson, Tucker, & Li, 2014). The ingestion of low GI foods may support regulation in weight and be a beneficial effect in the treatment of obesity (Aller, Abete, Astrup, Martinez, & van Baak, 2011).…”

Glycemic Index and Microstructure Evaluation of Four Cereal Grain Foods

“…However as a counter argument to this view, a recent review by Livesey et al. (), show that the nature of dietary fiber or wholegrains cannot effectively predict GI values, which underscores the need to develop country specific GI databases.…”