title: Effects of a carbohydrate-restricted diet with and without supplemental soluble fiber on plasma low-density lipoprotein cholesterol and other clinical markers of cardiovascular risk.
abstract: Carbohydrate-restricted diets (CRDs) promote weight loss, reductions in plasma triacylglycerol (TAG) levels, and increases in high-density lipoprotein cholesterol (HDL-C) levels but may cause undesirable low-density lipoprotein cholesterol (LDL-C) responses in some people. The objective of the present study was to determine the effect of adding soluble fiber to a CRD on plasma LDL-C and other traditionally measured markers of cardiovascular disease. Using a parallel-arm, double-blind, placebo-controlled design, 30 overweight and obese men (body mass index, 25-35 kg/m(2)) were randomly assigned to supplement a CRD with soluble fiber (Konjac-mannan, 3g/d) (n = 15) or placebo (n = 15). Plasma lipids, anthropometrics, body composition, blood pressure, and nutrient intake were evaluated at baseline and at 6 and 12 weeks. Compliance was excellent as assessed by 7-day weighed dietary records and ketonuria. Both groups experienced decreases in (P < .01) body weight, percent body fat, systolic blood pressure, waist circumference, and plasma glucose levels. After 12 weeks, HDL-C and TAG improved significantly in the fiber (10% and -34%) and placebo (14%, -43%) groups. LDL-C decreased by 17.6% (P < .01) at week 6 and 14.1% (P < .01) at week 12 in the fiber group. Conversely, LDL-C reductions were significant in the placebo group only after 12 weeks (-6.0%, P < .05). We conclude that although clearly effective at lowering LDL-C, adding soluble fiber to a CRD during active and significant weight loss provides no additional benefits to the diet alone. Furthermore, a CRD led to clinically important positive alterations in cardiovascular disease risk factors.
authors.affiliation: Department of Nutritional Sciences, University of Connecticut, Storrs, CT 06269-4017, USA. woodR@dom.pitt.edu
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Wood
authors.forename: Maria Luz
authors.initials: ML
authors.lastname: Fernandez
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Sharman
authors.forename: Ricardo
authors.initials: R
authors.lastname: Silvestre
authors.forename: Christine M
authors.initials: CM
authors.lastname: Greene
authors.forename: Tosca L
authors.initials: TL
authors.lastname: Zern
authors.forename: Sudeep
authors.initials: S
authors.lastname: Shrestha
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Judelson
authors.forename: Ana L
authors.initials: AL
authors.lastname: Gomez
authors.forename: William J
authors.initials: WJ
authors.lastname: Kraemer
authors.forename: Jeff S
authors.initials: JS
authors.lastname: Volek
mesh_terms: D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure; D001823:Body Composition / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D002318:Cardiovascular Diseases / Q000097:blood / Q000517:prevention & control*; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood*; D050528:Diet, Carbohydrate-Restricted / Q000379:methods*; D004043:Dietary Fiber / Q000008:administration & dosage; D004311:Double-Blind Method; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male; D008351:Mannans / Q000494:pharmacology*; D008875:Middle Aged; D014280:Triglycerides / Q000097:blood
chemical_list: D001786:Blood Glucose; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D004043:Dietary Fiber; D007328:Insulin; D008351:Mannans; D014280:Triglycerides; C022901:(1-6)-alpha-glucomannan