Neither raw nor retrograded resistant starch lowers fasting serum cholesterol concentrations in healthy normolipidemic subjects

Abstract

The question addressed was whether dietary resistant starch would lower serum cholesterol and triacylglycerol concentrations in healthy normolipidemic subjects. In a randomized single-blind 3 x 3 Latin-square study with corrections for any carryover effects, 27 males and 30 females consumed supplements containing glucose or resistant starch (RS) from raw high-amylose cornstarch (RS2) or from retrograded high-amylose cornstarch (RS3). The RS2 and RS3 supplements provided 30 g RS/d. Each type of supplement was consumed in addition to the habitual diet for 3 wk. At the end of each 3-wk period, fasting blood samples and a 24-h food-consumption recall were obtained from each subject. The subjects collected 24-h urine samples for lithium determination, which was added to the supplements to check compliance. Mean lithium recovery was 97% and did not differ between supplements. The mean composition of the background diet was similar when the three supplements were taken. Body weight remained constant throughout the study. There were no significant differences in the fasting concentrations of serum total, high-density-lipoprotein (HDL), and low-density-lipoprotein (LDL) cholesterol; triacylglycerols, or 3 alpha-hydroxy bile acids after consumption of glucose, RS2, or RS3. Evidence is presented that the lack of effect of RS2 and RS3 on serum lipid concentrations cannot be explained by insufficient statistical power, a low dose, or a short duration of treatment. The subjects reported softer stools and more gastrointestinal symptoms after supplementation with RS than after glucose. Neither the RS2 nor the RS3 supplements lowered serum lipid concentrations in healthy, normolipidemic men and women.

Resistant Starch Supplementation Influences Blood Lipid Concentrations and Glucose Control in Overweight Subjects

“…Many in vivo studies have shown that RS may be readily fermented by colonic microflora, but differences in fermentability were found (29). It has been claimed that starch is com pletely fermented by gut bacteria (12). Further study is needed to clarify the exact colonic process followed by the ingestion of different types of RS.…”

“…The differences in nature of RS, study subjects as well as feeding regiments may be the contributing factors. In fact, the differences in RS have been suggested to play a role in glycemic response (12), wolf et al (22) have found no significant glucose lower ing action with RS from corn, whereas wakabayashi et al (21) have noticed a beneficial glycemic response with RS from potato.…”

Nutritional Implications Of Resistant Starch

“…In a pilot study by Olesen et al (1995) there was no significant effect on blood cholesterol concentration by 50 g/d of raw potato starch or high amylose corn starch, but it was stressed that the baseline values fluctuated considerably, masking any minor effects. A more comprehensive study recently performed by Heijnen et al (1996) in healthy volunteers indicated that there was no significant effect of supplementing 30 g/d RS 2 or RS 3 to the diet on fasting levels of serum total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol, or triacylglycerols. Ranganathan et al (1994) observed, within an acute study, that a high amylose corn starch had no effect on blood non-esterified fatty acids (NEFA) and NEFA oxidation comparable with cellulose.…”

Macronutrients and type 1 diabetes (revision number 6)

“…Four randomised controlled trials were identified that presented evidence on resistant starch supplementation in relation to measures of energy intake, three of which were included in a meta-analysis (De Roos et al, 1995;Heijnen et al, 1996;Jenkins et al, 1998). One trial was not included in the meta-analysis as it was unclear which type of resistant starch subjects were supplemented with (Ells et al, 2005) (Cardio-metabolic review, energy intake and eating motivation chapter, p126-129).…”