Untitled

REVIEW
Dietary carbohydrate: relationship to cardiovascular
disease and disorders of carbohydrate metabolism
J Mann
European Journal of Clinical Nutrition (2007) 61 (Suppl 1), S100–S111
& 2007 Nature Publishing Group All rights reserved 0954-3007/07 $30.00
www.nature.com/ejcn
Department of Human Nutrition, Edgar National Centre for Diabetes Research, University of Otago, Dunedin, New Zealand
The nature of carbohydrate is of considerable importance when recommending diets intended to reduce the risk of type II
diabetes and cardiovascular disease and in the treatment of patients who already have established diseases. Intact fruits,
vegetables, legumes and wholegrains are the most appropriate sources of carbohydrate. Most are rich in nonstarch
polysaccharides (NSPs) (dietary fibre) and other potentially cardioprotective components. Many of these foods, especially those
that are high in dietary fibre, will reduce total and low-density lipoprotein cholesterol and help to improve glycaemic control in
those with diabetes. There is no good long-term evidence of benefit when NSPs or other components of wholegrains, fruits,
vegetables and legumes are added to functional and manufactured foods. Frequent consumption of low glycaemic index foods
has been reported to confer similar benefits, but it is not clear whether such benefits are independent of the dietary fibre content
of these foods or the fact that low glycaemic index foods tend to have intact plant cell walls. Furthermore, it is uncertain whether
functional and manufactured foods with a low glycaemic index confer the same long-term benefits as low glycaemic index
plant-based foods. A wide range of carbohydrate intake is acceptable, provided the nature of carbohydrate is appropriate.
Failure to emphasize the need for carbohydrate to be derived principally from wholegrain cereals, fruits, vegetables and legumes
may result in increased lipoprotein-mediated risk of cardiovascular disease, especially in overweight and obese individuals who
are insulin resistant.
European Journal of Clinical Nutrition (2007) 61 (Suppl 1), S100–S111; doi:10.1038/sj.ejcn.1602940
Keywords: cardiovascular disease; impaired carbohydrate metabolism
Dietary carbohydrate and cardiovascular disease
Traditional dietary patterns, which are high in carbohydrate,
are associated with low rates of coronary heart disease
(CHD). This appears to be the case regardless of the
carbohydrate containing primary staple, for example rice in
most Asian countries and a range of cereals, root crops and
pulses in different parts of Africa. However, cross-cultural
comparisons provide no indication as to whether the
percentage of energy intake derived from total carbohydrate
intake, total quantity of carbohydrate, particular classes of
carbohydrate and other nutrients, which are found in
carbohydrate-containing foods or method of food preparation,
account for the cardioprotection afforded by such
traditional carbohydrate-containing diets. Furthermore, it is
possible that cardiovascular risk is reduced simply because
Correspondence: Professor J Mann, Department of Human Nutrition, Edgar
National Centre for Diabetes Research, University of Otago, Dunedin, New
Zealand.
E-mail: jim.mann@stonebow.otago.ac.nz
traditional high carbohydrate diets are low in fat, especially
saturated fat, or because they promote satiety and thus
protect against overweight and obesity. Indeed, it is
conceivable that high carbohydrate diets simply act as a
marker for some other protective factor. Prospective epidemiological
studies and a range of experimental approaches
examining the effects of carbohydrates on cardiovascular risk
factors have attempted to clarify the role of total carbohydrate
and carbohydrate classes (sugars, oligosaccharides
and polysaccharides) and subgroups (for example starch,
nonstarch polysaccharide (NSP)) in CHD and stroke.
Prospective epidemiological studies
Several limitations are common to all prospective studies
examining the relationship between foods and nutrients and
disease risk. However, there are issues that are of particular
relevance when considering the role of carbohydrates. The
lack of consistency in the methods used for the measurement
of different classes and subgroups of carbohydrate,