Viscous and nonviscous fibres, nonabsorbable and low glycaemic index
carbohydrates, blood lipids and coronary heart disease.
Curr Opin Lipidol. 2000 Feb;11(1):49-56.
Jenkins DJ, Kendall CW, Axelsen M, Augustin LS, Vuksan V.
Clinical Nutrition & Risk Factor Modification Center, St. Michael's
Hospital, and Department of Nutritional Sciences, Faculty of Medicine,
University of Toronto, Ontario, Canada. email@example.com
Viscous fibres such as guar, glucomannans, pectins, oat betaglucan
and psyllium continue to be seen as hypocholesterolaemic. Nevertheless,
in large cohort studies, ironically it is the insoluble cereal fibre
that has been demonstrated to relate negatively to cardiovascular disease
and diabetes, despite an absence of effect on fasting lipids or postprandial
glycaemia. In general, resistant or nonabsorbable starch is lipid neutral,
whereas some nonabsorbable sugars or oligosaccharides may raise serum
cholesterol, possibly through providing more acetate after colonic fermentation
by colonic microflora. On the other hand, fructo-oligosaccharides appear
to reduce serum triglycerides for reasons that are not entirely clear.
Of possibly greater recent interest have been the carbohydrates that
are not so much resistant to absorption, but rather are slowly absorbed.
They possess some of the features of dietary fibre in providing a substrate
for colonic bacterial fermentation. In the small intestine, however,
they form lente or sustained release carbohydrate. In the form of low
glycaemic index foods, lente carbohydrate consumption has been shown
to relate to improved blood lipid profiles in hyperlipidaemic individuals
and improved glycaemic control in diabetes. In larger cohort studies,
low glycaemic index foods or low glycaemic load diets have been associated
with higher HDL-cholesterol levels and reduced incidence of diabetes
and cardiovascular disease.