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.
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.
Wood
Richard J
RJ
Department of Nutritional Sciences, University of Connecticut, Storrs, CT 06269-4017, USA. woodR@dom.pitt.edu
Fernandez
Maria Luz
ML
Sharman
Matthew J
MJ
Silvestre
Ricardo
R
Greene
Christine M
CM
Zern
Tosca L
TL
Shrestha
Sudeep
S
Judelson
Daniel A
DA
Gomez
Ana L
AL
Kraemer
William J
WJ
Volek
Jeff S
JS
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
D001786:Blood Glucose; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D004043:Dietary Fiber; D007328:Insulin; D008351:Mannans; D014280:Triglycerides; C022901:(1-6)-alpha-glucomannan