Saccharides and Cognition

Talitha Best University of South Australia

Polysaccharides: “Polysaccharides, in many forms, play a central role

in all living organisms for supply and storage of energy and/or structural integrity and protection of cells.”

Z. Persin et al (2011). Carbohydrate Polymers 84:22–32

Polysaccharides are becoming recognised as one of the active components of many plants such as:

aloe vera, astragalus,

mushrooms, broccoli,

kale, carrots,

radishes, artichokes,

seaweed, tea leaves, & larch

Chen et al., 2009. Journal of Food Science. 74 (6), 46

Dietary polysaccharides: Immune function modulators

– promoting the production of antibodies – inhibiting tumour cell proliferation – inhibiting virus entering cells and replication – increasing activity of antioxidant enzyme; scavenging free radicals – inhibiting lipid peroxidation

Gut health and digestive function Anti-inflammatory

– regulating cytokine expression

He, X., et al. (2012). Journal of Experimental and Integrative Medicine, 2(1):15-27.

Schepetkin, I. A., & Quinn, M. T. (2006). International Immunopharmacology, 6, 317- 333. Qiang, X. et al.(2009). Carbohydrate Polymers, 77, 435-441.

Alavi, A. et al.(2011). European Journal of Clinical Nutrition, 1-9. Wong, K. et al.(2011) Food Hydrocolloids, 25: 150-158.

Mechanisms in the brain (polysaccharide fractions containing mannose, galactose, fucose,

xylose, glucose, rhamnose & arabinose)

Neuroprotective function - against dopamine depletion, - attenuate hypoxic induced damage, - decrease lipid peroxidation - increase antioxidant activity

Electrical activity of cells in hippocampus - increased LTP (synaptic plasticity) both i.c.v and i.v injections

Connections between cells/synaptic function Transport and regulation of neurotransmitters Central nervous system development and integrity

Nelson, E., Ramberg, J., Best, T., & Sinnott, R. (2012). Nutritional Neuroscience, 15(4), 149-162 Best, T. Kemps, E., Bryan, J. (2005) Nutrition Reviews, 63 (12) 4009-418

. Zhang et al., (2010). International Journal of Biological Macromolecules. 47, 546–550

prevention of cognitive aging

ABILITY

infant child adult elderly

Cognition throughout life

http://archive.treasury.gov.au

Cross sectional research N= 1183 Middle-aged adults (40-60 yrs)

Saccharide + ve impact on

health Memory Functioning

Memory problems

Mnemonic usage

Reading recall Retrospective functioning

Fucose ** ** **

Mannose ** **

Galactose ** ** ** **

Rhamnose ** **

Arabinose **

Xylose **

Best , T., Kemps, E., & Bryan , J. (2009). British Journal of Nutrition. 101. 93-99.

The greater our knowledge increases the more our ignorance unfolds.

- John F. Kennedy-

Cognition & Mood

Inflammation

Glycaemic control

Cortisol - stress

Polysaccharides

Blood flow

Oxidative stress

Insulin resistance

Possible mechanisms: Direct effects: - Can affect specific neuronal processes that play an

important role in cognitive functioning Changes in physiological mechanisms that are related

cognitive health: - Glucose regulation - Antioxidant - Inflammation - Gut microbiota

Means and standard errors of capillary blood glucose levels for treatment conditions

Best, T., Howe,P., Bryan,J., Buckley, J.& Scholey, A. 2012 Under review

Possible mechanisms: Direct effects: - Can affect specific neuronal processes that play an

important role in cognitive functioning Changes in physiological mechanisms that are related

cognitive health: - Glucose regulation - Antioxidant – oxidative stress - Inflammation - Gut microbiota changes

Future research - where to from here? • Characterisation, isolation and extraction of polysaccharides • Understanding the impact and interactions of polysaccharides

with: – lipids – lipid absorption – plasma glucose – serum insulin metabolism – their effect on digestion, diabetes, obesity and cardiovascular risks

• Exploration of mechanisms – i.e., exact receptors on cells recognised by polysaccharides, signalling

pathways and active sites of polysaccharides

• New polysaccharide based products

Take home:

- There are biologically plausible mechanisms through which

dietary polysaccharides might influence cognitive health

- Preliminary evidence indicates beneficial effects in middle-aged and young adults.

- Potential for polysaccharides to maintain cognitive function into older adulthood.

TEMPLATE - Standard Bullet Slide

Acknowledgements Participants Co-Investigators: Prof P. Howe - Nutritional Physiology Research Centre, UniSA Dr J. Bryan - School of Psychology, Social Work and Policy, UniSA Assoc Prof J. Buckley - Nutritional Physiology Research Centre, Sansom Institute for Health Research - UniSA Prof A. Scholey - Centre for Human Psychopharmacology, Swinburne University of Technology Funding: Partial funding to author TB from R&D Mannatech Inc (Dallas, TX) Partial funding DP1093834 from the Australian Research Council to author AS.