Class 2 resistant starches lower plasma and liver lipids and improve mineral retention in rats

The effects of raw potato starch (RPS) and high amylose corn starch (HAS) o n cecal digestion, lipid metabolism and mineral utilization (Ca and My) wer e compared in rats adapted to semipurified diets. The diets provided either 710 g wheat starch/100 g diet (control) alone or 510 g wheat starch/100 g diet plus 200 g resistant starch/100 g (RPS or HAS). Compared with rats fed the control diet, significant cecal hypertrophy (240% after 7 d of the fib er consumption) and short-chain fatty acids accumulation (especially propio nic and butyric acids) occurred after both resistant starch diets. Apparent Ca, Mg, Zn, Fe and Cu absorptions were similarly enhanced by RPS and HAS ( 50, 50, 27, 21 and 90%, respectively). Cholesterol absorption was reduced t o 14% of intake in rats fed RPS or HAS compared with 47% absorption in cont rol rats. RPS and HAS were also effective in lowering plasma cholesterol (- 31 and -27%, respectively) and triglycerides (-28 and -22%, respectively). There was no effect of the diets on cholesterol in d > 1.040 kg/L lipoprote ins (HDL), whereas RPS and HAS depressed cholesterol in d( 1.040 kg/L lipop roteins (especially in triglyceride-rich lipoproteins). Moreover, there wer e lower concentrations of cholesterol (-50 and -40%, respectively) and trig lycerides (-53 and -47%, respectively) in the livers of RPS- and HAS-fed ra ts. Thus, RPS and HAS have similar effects on intestinal fermentation, mine ral utilization and cholesterol metabolism in rats.