title: High dietary fat and cholesterol exacerbates chronic vitamin C deficiency in guinea pigs.
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.
authors.affiliation: Section of Biomedicine, Department of Veterinary Disease Biology, Faculty of Life Sciences, University of Copenhagen, Ridebanevej 9, DK-1870 Frederiksberg C, Denmark.
authors.forename: Henriette
authors.initials: H
authors.lastname: Frikke-Schmidt
authors.forename: Pernille
authors.initials: P
authors.lastname: Tveden-Nyborg
authors.forename: Malene Muusfeldt
authors.initials: MM
authors.lastname: Birck
authors.forename: Jens
authors.initials: J
authors.lastname: Lykkesfeldt
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000378:metabolism*; D001205:Ascorbic Acid / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism*; D001206:Ascorbic Acid Deficiency / Q000097:blood / Q000378:metabolism*; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D002791:Cholesterol, Dietary / Q000009:adverse effects* / Q000097:blood; D002908:Chronic Disease; D004041:Dietary Fats / Q000009:adverse effects* / Q000097:blood; D004195:Disease Models, Animal; D006168:Guinea Pigs; D006706:Homeostasis; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects*
chemical_list: D000975:Antioxidants; D002791:Cholesterol, Dietary; D004041:Dietary Fats; D001205:Ascorbic Acid