The effect of the daily intake df inulin on fasting lipid, insulin and glucose concentrations in middle-aged men and women

The present study was carried out to examine the effect of the daily intake of 10 g inulin on fasting blood lipid, glucose and insulin levels in healt hy middle-aged men and women with moderately raised total plasma cholestero l (TC) and triacylglycerol (TAG) levels. This study was a double-blind rand omized placebo-controlled parallel study in which fifty-four middle-aged su bjects received either inulin or placebo for a period of 8 weeks. Fasting b lood samples were collected before the supplementation period (baseline sam ples 1 and 2, separated by 1 week) and at weeks 4 and 8, with a follow-up a t week 12. Compared with baseline values, insulin concentrations were signi ficantly lower at 4 weeks (P < 0.01) in the inulin group. There was a trend for TAG values, compared with baseline, to be lower in the inulin group at 8 weeks (P < 0.08) returning to baseline concentrations at week 12. On com parison of the inulin and placebo groups, the fasting TAG responses over th e 8-week test period were shown to be significantly different (P < 0.05, re peated measures ANOVA), which was largely due to lower plasma TAG levels in the inulin group at week 8. The percentage change in TAG levels in the inu lin group during the 8-week study was shown to correlate with the initial T AG level of the subjects (r(s) -0.499, P = 0.004). We therefore conclude th at the daily addition of 10 g inulin to the diet significantly reduced fast ing insulin concentrations during the 8-week test period and resulted in lo wer plasma TAG levels, particularly in subjects in whom fasting TAG levels were greater than 1.5 mmol/l. These data support findings from animal studi es that fructans influence the formation and/or degradation of TAG-rich lip oprotein particles, and the insulin data are also consistent with recent st udies showing attenuation of insulin levels in fructan-treated rats.