Full Papers

Nutritional Toxicology

High dietary fat and cholesterol exacerbates chronic vitamin C deficiency in guinea pigs

Henriette Frikke-Schmidt^a1, Pernille Tveden-Nyborg^a1, Malene Muusfeldt Birck^a1 and Jens Lykkesfeldt^a1 c1

^a1 Section of Biomedicine, Department of Veterinary Disease Biology, Faculty of Life Sciences, University of Copenhagen, Ridebanevej 9, DK-1870 Frederiksberg C, Denmark

Abstract

Vitamin C deficiency – or hypovitaminosis C defined as a plasma concentration below 23 μm – is estimated to affect hundreds of millions of people in the Western world, in particular subpopulations of low socio-economic status that tend to eat diets of poor nutritional value. Recent studies by us have shown that vitamin C deficiency may result in impaired brain development. Thus, the aim of the present study was to investigate if a poor diet high in fat and cholesterol affects the vitamin C status of guinea pigs kept on either sufficient or deficient levels of dietary ascorbate (Asc) for up to 6 months with particular emphasis on the brain. The present results show that a high-fat and cholesterol diet significantly decreased the vitamin C concentrations in the brain, irrespective of the vitamin C status of the animal (P < 0·001). The brain Asc oxidation ratio only depended on vitamin C status (P < 0·0001) and not on the dietary lipid content. In plasma, the levels of Asc significantly decreased when vitamin C in the diet was low or when the fat/cholesterol content was high (P < 0·0001 for both). The Asc oxidation ratio increased both with low vitamin C and with high fat and cholesterol content (P < 0·0001 for both). We show here for the first time that vitamin C homoeostasis of brain is affected by a diet rich in fat and cholesterol. The present findings suggest that this type of diet increases the turnover of Asc; hence, individuals consuming high-lipid diets may be at increased risk of vitamin C deficiency.

(Received March 17 2010)

(Revised July 02 2010)

(Accepted July 05 2010)

(Online publication September 28 2010)

Key Words:

• Vitamin C deficiency;
• High-fat diet;
• Brain

Correspondence:

^c1 Corresponding author: Professor J. Lykkesfeldt, fax +45 35 35 35 14, email jopl@life.ku.dk

Footnotes

Abbreviations: Asc, ascorbate; DHA, dehydroascorbic acid