Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Health and Immune Function Benefits of Kiwifruit Derived Vitamin C by Dr Anitra Carr

396 views

Published on

Dr Anitra Carr, Researcher at University of Otago, New Zealand, presentation at 1st International Symposium on Kiwifruit and Health: http://www.kiwifruitsymposium.org/presentations/health-and-immune-function-benefits-of-kiwifruit-derived-vitamin-c/

Vitamin C is an essential micronutrient. Unlike most animals, we have lost the ability to synthesise our own vitamin C and must therefore obtain it from our diet. Fresh fruit and vegetables are the best source of vitamin C, and regular and adequate daily intake of vitamin C is required to prevent marginal vitamin C status (hypovitaminosis C) and the potentially fatal deficiency disease scurvy. Kiwifruit are an outstanding source of vitamin C with one kiwifruit providing twice the Recommended Dietary Intake (RDI) of vitamin C.

Published in: Healthcare
  • Be the first to comment

Health and Immune Function Benefits of Kiwifruit Derived Vitamin C by Dr Anitra Carr

  1. 1. Health and Immune Function Benefits of Kiwifruit-Derived Vitamin C Dr Anitra C. Carr University of Otago, Christchurch
  2. 2. Presentation outline • Bioavailability studies • Functional studies Well-being Immune function • Recommended Dietary Intake
  3. 3. Vitamin C content of food
  4. 4. Vitamin C bioavailability studies • KiwiC pilot study Pilot study to determine dose of kiwifruit for optimal vitamin C uptake into circulation • Bioavailability study Uptake of kiwifruit-derived vitamin C into biological fluids, cells and tissues
  5. 5. Pilot bioavailability study
  6. 6. Urinary vitamin C excretion Carr et al. J Nutr Sci, 2012. 1 gold kiwifruit = 100 mg vitamin C Plasma vitamin C uptake Pilot bioavailability study
  7. 7. Main bioavailability study
  8. 8. Bioavailability Study Protocol Measurements: Dietary Intake Plasma Urine Semen Leukocytes Muscle tissue HPLC-ECD
  9. 9. Main Bioavailability Study Carr et al. Am J Clin Nutr, 2013. () 0.5 kiwifruit/d (50 mg/d vitamin C) (○) 2 kiwifruit/d (200 mg/d vitamin C) Saturating Adequate Marginal
  10. 10. Summary of bioavailability studies • Optimal intake of kiwifruit 0.5 kiwifruit/d (50 mg/d vitamin C) – adequate 2 kiwifruit/d (200 mg/d vitamin C) – saturating/optimal • Tissue and cell uptake Linear uptake of kiwifruit-derived vitamin C into skeletal muscle tissue and white blood cells
  11. 11. Functions of vitamin C Enzyme cofactor Protein 3◦ structure Hormone & neurotransmitter synthesis Mitochondrial energy production Metabolic regulation Epigenetic regulation
  12. 12. Vitamin C functional studies • Kiwifruit and well-being Effect of kiwifruit-derived vitamin C on measures of well-being e.g. vigour • Kiwifruit and immune function Effect of kiwifruit-derived vitamin C on measures of leukocyte function
  13. 13. Effect of kiwifruit on well-being The symptoms of depression, fatigue and irritability are known to precede the overt physical symptoms of the vitamin C deficiency disease scurvy.
  14. 14. P = 0.061 Effect of kiwifruit on well-being ± 2 kiwifruit/d (200 mg/d vitamin C) n=17 0.5 kiwifruit/d vs 2 kiwifruit/d POMS – Profile of Mood States Carr et al. J Nutr Sci, 2013. P = 0.029 High TMD sub-group (± 2 kiwifruit/d) n=8
  15. 15. Potential well-being mechanism Carnitine biosynthesis
  16. 16. Neurotransmitter synthesis Potential well-being mechanisms
  17. 17. Neutrophils and immune function www.slideshare.net/kiweewab/lecture6-inflammationpptx
  18. 18. Neutrophil bacterial killing Neutrophil Extracellular Traps (NETs) courses.washington.edu/conj/bloodcells/phagocytes.htm www.nature.com/nm/journal/v16/n9/covers/index.htm
  19. 19. Neutrophil apoptosis and clearance www.nature.com/nm/journal/v16/n9/covers/index.htm
  20. 20. Kiwifruit and neutrophil function Measurements: Plasma vitamin C Neutrophil vitamin C Neutrophil chemotaxis Neutrophil oxidant production Neutrophil extracellular traps Neutrophil apoptosis
  21. 21. Kiwifruit and neutrophil function
  22. 22. Kiwifruit-derived micronutrients
  23. 23. Summary of functional studies • Kiwifruit enhances well-being 2 Kiwifruit/d enhances well-being by ↓ fatigue, ↑ vigour • Kiwifruit enhances neutrophil function 2 Kiwifruit/d enhances neutrophil vitamin C levels and functions e.g. ↑ chemotaxis and ↑ oxidant production
  24. 24. International RDIs for vitamin C UK 40 mg/d AUS/NZ 45 mg/d* USA/Canada 75-90 mg/d** Europe 95-110 mg/d*** * Based on an intake at which body content is halfway between tissue saturation and the point at which clinical signs of scurvy appear. ** Based on an amount that provides antioxidant protection and derived from near maximal neutrophil concentrations with minimal urinary loss. *** Based on the amount of vitamin C that compensates for metabolic losses and ensures a fasting ascorbate plasma level of 50 µmol/L.
  25. 25. NZ MOH Suggested Dietary Target for the reduction of chronic disease risk 200 mg/d Time for a new RDI for vitamin C? Adapted from Levine et al. PNAS, 1996. Saturating Adequate Marginal Deficient  Animals  New USA RDI  Old USA RDI  NZ/AUS RDI
  26. 26. Acknowledgements Vitamin C Team Prof Margreet Vissers Dr Stef Bozonet Dr Anitra Carr Dr Juliet Pullar Vitamin C Funding Zespri International Ltd Ministry of Business, Innovation & Employment

×