Carbohydrates and Health

1 Introduction and methods
Background
1.1 Dietary carbohydrates and their role in health were last considered by the
Committee on Medical Aspects of Food Policy (COMA, the predecessor of the
Scientific Advisory Committee on Nutrition) in the following reports: Sugars
and Human Disease (COMA, 1989), Dietary Reference Values for Food Energy
and Nutrients for the United Kingdom (COMA, 1991) and Nutritional Aspects of
Cardiovascular Disease (COMA, 1994). Considerable evidence has emerged since
these reports were published, particularly in the areas of cardio-metabolic,
colo-rectal and oral health. It was therefore considered important to review the
literature on carbohydrate intake in relation to these health outcomes and to
ensure that the dietary reference values reflect the current evidence base.
Terms of Reference
1.2 The Scientific Advisory Committee on Nutrition (SACN) was requested by the
Food Standards Agency and the Department of Health to provide clarification of
the relationship between dietary carbohydrate and health and make public health
recommendations. To achieve this they were asked to review:
• The evidence for the role of dietary carbohydrate in colo-rectal health in adults
(including colo-rectal cancer, irritable bowel syndrome, constipation) and in
childhood and infancy.
• The evidence on dietary carbohydrate and cardio-metabolic health (including
cardiovascular disease, insulin resistance, glycaemic response and obesity).
• The evidence in respect to dietary carbohydrates and oral health.
• The terminology, classification and definitions of types of carbohydrates in the
diet.
Methodology
1.3 Due to the wealth of data available and because of the concerns around their
limitations, case-control, cross-sectional and ecological studies were not
considered. Only prospective cohort studies and randomised controlled trials
were considered for this report. Evidence on adverse effects of very high intakes
of specific carbohydrates, e.g. gastrointestinal symptoms, was not part of the remit
of this report.
1.4 Systematic reviews on cardio-metabolic, colo-rectal and oral health in relation to
carbohydrates and food sources of carbohydrates were commissioned to inform
this report (see Annex 1 for individual systematic reviews). These were based on
literature published through December 2009, November 2010 and January 2011,
respectively. The search strategy and inclusion and exclusion criteria are described
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