Short-Term Supplementation of a Moderate Carbohydrate Diet with Psyllium Reduces Fasting Plasma Insulin and Tumor Necrosis Factor-α in Patients with Type 2 Diabetes Mellitus

ABSTRACT

The purpose of this study was to compare effects of a moderate carbohydrate diet supplemented with psyllium with those of a lower carbohydrate diet supplemented with placebo powder on glycemic control in patients with type 2 diabetes (T2D). In an open randomized controlled trial, 37 patients with T2D with body mass index (BMI) 25–35 kg/m2 received either a low-energy, moderate carbohydrate diet plus 7 grams of psyllium powder (MoCyllium group) or a low-energy, lower carbohydrate diet plus placebo powder (LoCarb group) for 2 weeks. Fasting and 2-hour postprandial plasma glucose, insulin, and tumor necrosis factor-α (TNF-α) as well as the homeostasis model assessment of insulin resistance (HOMA-IR) were determined at the beginning and end of the 2-week period. Postprandial samples were obtained after ingestion of a standardized breakfast meal in both groups. Body weight change did not differ between the two groups. There was no significant intervention effect on fasting plasma glucose. Fasting plasma insulin and TNF-α significantly decreased from baseline in the MoCyllium group (p = .01). The differences of absolute change of insulin and TNF-α between the groups were statistically significant (p = .002 and p = .017, respectively). Insulin sensitivity, evaluated by HOMA-IR, increased significantly in the MoCyllium group (p = .016), and comparison of absolute change between the groups showed a trend toward statistical significance. No statistical differences were detected among postprandial glucose, insulin, and TNF-α concentrations. The finding supports the concept that in diabetic patients with cultural preferences to a higher carbohydrate diet, an increase in soluble fiber intake should be encouraged.

KEYWORDS:

• diabetes
• diet
• insulin
• psyllium
• TNF-α

Acknowledgments

The authors thank Marjan Rismanchi for her laboratory technical assistance.

Declaration interest

The authors declare no conflicts of interest. The authors alone are responsible for the content and writing of the article.

Funding

The study was supported by a National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

About the authors

Mahdieh Kamalpour, MS, is a dietitian at a governmental health center in Tehran province. Her research interests include nutrition, diabetes and obesity.

Hamid Ghalandari, MS, graduated from Shahid Beheshti University of Medical Sciences in 2016 with a MS in Nutrition science. His research interests are in prevention of diabetes, obesity and cardiovascular disease.

Javad Nasrollahzadeh, PhD, is an assistant professor in the department of clinical nutrition and diet therapy at Shahid Beheshti University of Medical Sciences. His research interests include chronic disease prevention by nutritional interventions and health-promoting compounds of foods.