The effects of dietary methylcellulose in man

Following a 7-day control period, five male volunteers consumed, on each of 23 consecutive days, a weight of methylcellulose (MC) equal to ten times the acceptable daily intake (25 mg/kg b.w.) approved by the EEC and the Joint FAO/WHO Expert Committee on Food Additives (JECFA). The MC was well tolerated; no allergic responses were reported. Measurements before and at the end of the test period showed that the ingestion of MC, as a pre-hydrated gel, acted as a bulking agent in terms of increased faecal wet (p less than 0.05) and dry weight, with intestinal transit time increasing for three but decreasing for two of the volunteers. Small changes, well within the normal ranges, occurred in some haematological indices, serum lipids and a few plasma biochemistry parameters. There were no changes in urinalysis parameters or breath hydrogen concentrations. There were small (p less than 0.05) reductions in faecal volatile fatty acids and neutral sterols (mumol/g dry weight). The decreases in blood glucose and plasma insulin after 60 min were also within the normal clinical range. The data provide no indications of any adverse effects of methylcellulose resulting from its ingestion for 23 days at the level of 250 mg/kg b.w.