Glycemic response of mashed potato containing high-viscocity hydroxypropylmethylcellulose

Potatoes generally have one of the highest glycemic index values of any food. Relatively small differences in the glycemic response (GR) of regularly consumed starch foods have shown beneficial effects on health. Lowering the GR of a potato-based meal has potentially wide-reaching health benefits. High-viscosity hydroxypropylmethylcellulose (HV-HPMC) is a modified cellulose dietary fiber extensively used in the food industry. We hypothesized that the GR of a high-glycemic index product such as mashed potato would be lower with the addition of HV-HPMC. In a nonblind, randomized, repeat-measure, crossover controlled trial, 15 healthy adults consumed portions of mashed potato with different doses (0%, 1%, 2%, and 4%) of a specially selected and optimized HV-HPMC and a reference food (glucose) on separate occasions. Five subjects were excluded from the final analysis due to noncompliance with study procedures. Capillary blood glucose was measured in fasted subjects and at 15, 30, 45, 60, 90, and 120 minutes after starting to eat. For each sample, the incremental area under the blood glucose response curve was calculated and the GR determined. There was a significant lowering effect of HV-HPMC on GR (P < .001) of mashed potato. Glycemic responses for all mashed potato samples with the HV-HPMC were significantly lower than the standard mashed potato: 1% level (P < .05), 2% level (P < .05), and 4% level (P < .05). However, there was no significant effect of the HV-HPMC dose on GR. We conclude that addition of select HV-HPMC to mashed potato blunts GR.