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 mM -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.

Maternal Vitamin C Deficiency during Pregnancy Persistently Impairs Hippocampal Neurogenesis in Offspring of Guinea Pigs

“…At P70, MWM animals displayed significantly lower levels of ASC in plasma, but not brain, compared to non-mazed animals (P<0.05). ASC oxidation ratio was assessed in the brain as a measure of redox imbalance [34], [35]. DEF animals showed significantly higher ASC oxidation ratio compared to the other groups (P<0.001; Table 2).…”

Vitamin C in Disease Prevention and Cure: An Overview

“…This model in contrast to others, enabled the effect of AA deficiency on lipid metabolism and atherosclerosis to be followed in long term experiments. In protracted hypovitaminosis C lasting for 10 weeks, there was a considerable accumulation of cholesterol in liver and also increased concentration in serum [83][84][85].…”

Non-Terminal Blood Sampling Techniques in Guinea Pigs

“…Guinea pigs possess several biological similarities to humans and are validated experimental animal models [1][2][3] . However, the use of guinea pigs currently represents a relatively narrow area of research and descriptive data on specific methodology is correspondingly scarce.…”

“…The guinea pig is a valuable and validated experimental animal model due to a number of biological similarities to humans such as a requirement for a dietary supply of vitamin C, comparable plasma lipoprotein metabolizing enzymes and lipoprotein profiles, as well as shared similarities with human placentation and prenatal development [1][2][3]7,8 . This makes the guinea pig an attractive and suitable model for studying effects of dietassociated diseases such as non-alcoholic fatty liver disease, cardiovascular diseases and putative effects of vitamin C deficiency but also the effect of e.g., maternal dietary intervention on the developing offspring.…”

“…This includes variation in the course of veins and arteries, and also that guinea pigs do not have a tail, thus have different requirements and options for both sampling and handling. Sampling from the saphenous or tarsal vein, induces minimal discomfort and stress in the animal and does not require anaesthesia 3,9 . This technique allows repeated samples of small amounts of blood (100-400 µl), e.g., to determine biochemical markers in plasma.…”