A recent meta-analysis has found that adopting a diet with a low glycemic index (GI) may confer similar protective effects against chronic diseases, including type 2 diabetes and cardiovascular disease, as diets high in fiber and whole grains.
Methodology:
The study, published in The Lancet Diabetes & Endocrinology and led by Dr. David J.A. Jenkins from the Department of Nutritional Sciences at the University of Toronto, aimed to assess the associations between GI, glycemic load, fiber, and whole grains with the incidence of type 2 diabetes, cardiovascular diseases, diabetes-related cancers, and all-cause mortality.
Researchers examined data from 10 large prospective cohort studies, each including over 100,000 participants, with a mean age of 56 years and a mean follow-up duration of 12.6 years. They compared the risks associated with different dietary factors and health outcomes.
Key Findings:
The findings revealed that high-GI diets were associated with an increased risk of type 2 diabetes, total cardiovascular disease, diabetes-related cancers, and all-cause mortality. Conversely, diets high in fiber and whole grains were linked to a reduced risk of these outcomes.
Compared to low-GI diets, high-GI diets were associated with a relative risk (RR) of 1.27 for type 2 diabetes, 1.15 for total cardiovascular disease, 1.05 for diabetes-related cancers, and 1.08 for all-cause mortality (statistically significant in women only).
Similarly, foods with high glycemic load were linked to an increased risk of incident type 2 diabetes and total cardiovascular disease compared to foods with a low glycemic load.
However, diets high in fiber and whole grains showed similar protective effects against these outcomes as low-GI diets.
In Practice:
The authors emphasized the importance of combining GI with fiber and whole grains in dietary recommendations to mitigate the risk of diabetes and related chronic diseases.
Limitations:
While the study provides valuable insights, it has limitations. Some outcomes had limited data availability, potentially affecting the robustness of the findings. Additionally, the comparisons between GI and fiber/whole grain exposure were based on a relatively small number of cohorts for certain disease outcomes.
Disclosures:
The study received funding from Banting and Best and the Karuna Foundation. The authors disclosed various ties with food and beverage industries, as well as other organizations, which may have influenced the study’s findings.
Conclusion:
Despite the limitations, this meta-analysis underscores the importance of considering both GI and dietary fiber/whole grains in promoting overall health and reducing the risk of chronic diseases. By incorporating a balanced diet rich in low-GI foods, fiber, and whole grains, individuals can potentially mitigate the risk of diabetes and related health conditions.