Glycoscience and functional sugars are at the forefront of nutrition research as ‘glyco’ structures appear to play an important role in organisms. Originally seen solely as a source of energy for cells with a structural component, the study of these structures now represents one of the most innovative areas in science and may contribute to solving some of society’s most prominent problems.
The classical function of carbohydrates in nutrition is related to the empirical and generic ‘fibre’ concept which contains very different components. One of the relevant ones involves improving or delaying the release and absorption of nutrients, usually changing the viscosity of food or the intestinal bolus but also changing the catalytic efficiencies of digestive enzymes. The other relevant component is the selective beneficial effect on microbiota.
With the development of glycoscience, there is the increasing understanding specific carbohydrates can improve health and prevent disease, with a molecular-defined mechanism. Carbohydrates are ubiquitous in cells; they can be found on all cell surfaces, in the cytosol and nucleus of eukaryotes, and within the extracellular matrix. Complex carbohydrates— monosaccharides or oligosaccharides attached to cells or other molecules (including DNA)—are involved in aspects as diverse as cell synthesis, structure, and cell to cell interactions, and play critical roles in development and disease.
While functional sugars in nutrition have great potential, they should not be considered a magical tool to confuse the population with false promises. The understanding of a healthy diet will need to go hand in hand with dialogues with regulatory bodies, education, public information, and marketing.
Beta-glucans are an example of multi-functional sugars. These natural glucose polysaccharides are found in many food sources including oats and other cereals, yeast and mushrooms, and have been shown to be beneficial for various areas of health. Beta-glucans have been shown to have cholesterol lowering properties and therefore can play an important role in reducing the risk of coronary heart disease. In 1991, the US Food and Drug Administration (FDA) approved a health claim for this effect and recommended a minimum of 3g of beta-glucans per day. Since then, studies have shown increased consumption of beta-glucans leads to a corresponding decrease in the risk of coronary heart disease. Beta-glucans from specific sources have also been found to have a beneficial impact on the immune system; they can bind to white blood cells and activate them leading to an increased natural immune defence against pathogens.
Promoting a healthy gut microflora is now understood to be important for infant and adult health and healthy ageing, as well as helping prevent allergies, infection, immune disease and chronic disease. Carbohydrate polymers can have a beneficial effect on human gut microbiota, and the oligosaccharides in breastmilk can help to improve long-term health. The prebiotic effect of ‘fibres’ are now linked to better-defined carbohydrates such as galacto-oligosaccharides (GOS) from bovine lactose and fructo-oligosaccharides (FOS) from plant inulins, which support the growth of the gastrointestinal microflora, changing its composition or activity, helping to improve wellbeing and health.
Examples of relevant functional sugars by the main nutritional function claimed:
Sugar release control/viscosity:
- Rare sugars: L-arabinose, D-tagatose, D-psicose, D-allulose
- Disaccharides: Isomaltulose, trehalose
- Polyols: Erythritol
- Polysaccharides: Polydextrose
- Resistant starch
- Fibres: Cellulose, hemicelulose, lignans
- Soluble fibre: beta-glucan, glucomannan, exo-polysaccharides
- Inulin: FOS, GOS, XOS, MOS
Sergio will be speaking on the Vitafoods Europe 2018 Centre Stage on the topic of functional sugars. Register to attend Vitafoods Europe 2018 here.