Beneficial effects of viscous dietary fiber
from Konjac-mannan in subjects with the insulin resistance syndrome:
results of a controlled metabolic trial.
Diabetes Care. 2000 Jan;23(1):9-14.
Vuksan V, Sievenpiper JL, Owen R, Swilley JA, Spadafora P, Jenkins DJ,
Vidgen E, Brighenti F, Josse RG, Leiter LA, Xu Z, Novokmet R.
Department of Nutritional Sciences, St. Michael's Hospital, University
of Toronto, Canada. email@example.com
Dietary fiber has recently received recognition for reducing the risk
of developing diabetes and heart disease. The implication is that it
may have therapeutic benefit in prediabetic metabolic conditions. To
test this hypothesis, we investigated the effect of supplementing a
high-carbohydrate diet with fiber from Konjac-mannan (KJM) on metabolic
control in subjects with the insulin resistance syndrome.
RESEARCH DESIGN AND METHODS:
We screened 278 free-living subjects between the ages of 45 and 65 years
from the Canadian-Maltese Diabetes Study. A total of 11 (age 55+/-4
years, BMI 28+/-1.5 kg/m2) were recruited who satisfied the inclusion
criteria: impaired glucose tolerance, reduced HDL cholesterol, elevated
serum triglycerides, and moderate hypertension. After an 8-week baseline,
they were randomly assigned to take either KJM fiber-enriched test biscuits
(0.5 g of glucomannan per 100 kcal of dietary intake or 8-13 g/day)
or wheat bran fiber (WB) control biscuits for two 3-week treatment periods
separated by a 2-week washout. The diets were isoenergetic, metabolically
controlled, and conformed to National Cholesterol Education Program
Step 2 guidelines. Serum lipids, glycemic control, and blood pressure
were the outcome measures.
Decreases in serum cholesterol (total, 12.4+/-3.1%, P<0.004; LDL,
22+/-3.9%, P<0.002; total/HDL ratio, 15.2+/-3.4%, P<0.003; and
LDL/HDL ratio, 22.2+/-4.1%, P< 0.002), apolipoprotein (apo) B (15.1+/-4.3%,
P<0.0004), apo B/A-1 ratio (13.1+/-3.4%, P< 0.0003), and serum
fructosamine (5.2+/-1.4%, P<0.002) were observed during KJM treatment
compared with WB-control. Fasting blood glucose, insulin, triglycerides,
HDL cholesterol, and body weight remained unchanged.
A diet rich in high-viscosity KJM improves glycemic control and lipid
profile, suggesting a therapeutic potential in the treatment of the
insulin resistance syndrome.
Randomized Controlled Trial