Research design for a randomized control trial to assess the effects of almond supplementation on insulin resistance, glycemic markers, and inflammation among overweight Asian Indians

Abstract

Background: Fatty acids play an important role in health and well-being; almonds have the highest amount of monounsaturated fatty acids (MUFAs) among the nuts. Western studies have shown positive health effects of almonds. However, well-designed studies are sparse on Asian Indians who have a unique phenotype with higher predisposition to diabetes and cardiovascular disease (CVD). Hence, the present study describes the design and methods of a clinical trial to assess the effect of almond supplementation on insulin resistance, glycemic markers, and inflammation in overweight Asian Indians. Methods and Outcome Assessments: Parallel-arm open-labeled, randomized controlled trial was conducted in Chennai, India. The study included 400 overweight and obese volunteers of age 25–65 years with a body mass index ≥23 kg/ m2 and with some having cardiometabolic risks. The participants in the intervention group received 43 g of almonds per day as recommended by the American Heart Association for 12 weeks, whereas the participants in the control arm followed their habitual dietary patterns and were advised not to consume any nuts. All other lifestyle habits were similar. The anthropometric, clinical, biochemical, and diet data of the participants were assessed periodically. Dietary 24-hour recalls and plasma percent fatty acid of the participants were assessed at the baseline and end of the study as a measure of participant compliance to protocol. This study also assessed gut hormone levels as a marker for satiety. The effects of almonds supplementation on anti-inflammatory and inflammatory markers such as adiponectin, monocyte chemoattractant protein-1, and tumor necrosis factor-! were also assessed. Discussion: The study findings, if benefits are found, would help to improve the MUFAs intake by a single supplementation of almonds daily to meet the dietary guidelines of 15% of total calories of MUFAs. In addition, it might aid in the prevention of obesity-related chronic diseases such as diabetes and CVDs by reducing the cardiometabolic risk factors. Trial Registration: The trial was registered in the clinical trial registry of India CTRI201710010251.