Plant-based diets may help reduce insulin requirement and cardiometabolic markers in diabetes patients

In the study published in Diabetes Research and Clinical Practice, the researchers found that both plant-based diets led to significant changes in insulin sensitivity, insulin requirements, and other markers of insulin resistance in people with insulin-treated type 2 diabetes. The magnitude of change was shown to be larger with large dietary changes.

"Both a WFPB and DASH diet, consumed without mandated calorie or portion restriction, led to a large, rapid reduction in insulin requirements among community-dwelling patients with insulin-treated type 2 diabetes," the researchers reported. "Within two weeks, participants were taking 39% less insulin while maintaining significantly reduced blood glucose."

Not much research has been done on insulin dosing changes following the adoption of plant-based diets. Thomas M Campbell, University of Rochester Medical Center, Rochester, NY, USA, and colleagues conducted a nonrandomized crossover trial utilizing two plant-based diets (Whole Food, Plant-Based, or WFPB, and Dietary Approaches to Stop Hypertension, or DASH) to evaluate acute changes in insulin requirements and associated markers among patients with insulin-treated type 2 diabetes.

The 4-week trial enrolled 15 participants with sequential, one-week phases: Baseline, DASH 1, WFPB, and DASH 2. Each diet was ad libitum and meals were provided. Each intervention was for 7 days. The baseline diet was followed by the DASH diet for 7 days, then a whole food, plant-based diet for 7 days, and then a return to the DASH diet for 7 days.

The authors reported the following findings:

· Compared to baseline, daily insulin usage was 24%, 39%, and 30% lower after DASH 1, WFPB, and DASH 2 weeks respectively.

· Insulin resistance (HOMA-IR) was 49% lower and the insulin sensitivity index was 38% higher at the end of the WFPB week before regressing toward baseline during DASH 2.

· Total, HDL, and LDL cholesterol, urinary glucose, leptin, and hsCRP decreased to a nadir at the end of the WFPB week before increasing during DASH 2.

To conclude, the study showed that adopting a WFPB diet or a DASH diet can result in rapid and large changes in insulin resistance, insulin requirements, inflammation, and cholesterol, with greater dietary changes producing greater benefits.

This study also demonstrates that individuals with more advanced type 2 diabetes may still realize large, comprehensive, and rapid benefits related to medication requirements, glycemic control, and cardiovascular risk factors from dietary change.

"These findings are relevant for counselling motivated patients who may wish to adopt a plant-based diet and need guidance regarding medication deprescribing," the researchers wrote.

"These findings have important implications not only for individual health risks but also for the cost of care. Additional study is warranted to evaluate the sustainability of durability of outcomes and behavioural changes over time," they concluded.

Reference:

Campbell TM, Campbell EK, Attia J, Ventura K, Mathews T, Chhabra KH, Blanchard LM, Wixom N, Faniyan TS, Peterson DR, Harrington DK, Wittlin SD. The acute effects of a DASH diet and whole food, plant-based diet on insulin requirements and related cardiometabolic markers in individuals with insulin-treated type 2 diabetes. Diabetes Res Clin Pract. 2023 Jul 5;202:110814. doi: 10.1016/j.diabres.2023.110814. Epub ahead of print. PMID: 37419391.