The total antioxidant capacity of the diet is an independent predictor of plasma β-carotene

Abstract

Objective: To investigate the contribution of the total antioxidant capacity (TAC) of the diet to plasma concentrations of b-carotene. Design: Cross-sectional study. Setting: Department of Public Health and Department of Internal Medicine and Biomedical Sciences, University of Parma. Subjects: A total of 247 apparently healthy adult men (n ¼ 140) and women (n ¼ 107). Methods: A medical history, a physical exam including height, weight, waist circumference and blood pressure measurements, a fasting blood draw, an oral glucose tolerance test and a 3-day food record. Results: We observe a negative trend across quartiles of plasma b-carotene for most biological variables clustering in the insulin resistance syndrome, as well as for traditional and new risk factors for type II diabetes and cardiovascular disease (CVD), including C-reactive protein and g-glutamyltranspeptidase (Po0.05). Regarding dietary characteristics, energy-adjusted intake of fat, fiber, fruits, vegetables, b-carotene, vitamin C, vitamin E and dietary TAC significantly increased with increasing plasma b-carotene (Po0.05), whereas alcohol intake decreased (P ¼ 0.013). Adjusted geometric means (95% confidence interval) of plasma b-carotene significantly increased across quartiles of dietary TAC, even when single dietary antioxidants were considered in the model (QI ¼ 0.087 mg/dl (0.073-0.102); QII ¼ 0.087 mg/dl (0.075-0.103); QIII ¼ 0.114 mg/dl (0.098-0.132) and QIV ¼ 0.110 mg/dl (0.093-0.130); P for linear trend ¼ 0.026). When the population was divided on the basis of alcohol consumption, this trend was also observed in subjects drinking o20 g alcohol/day (P ¼ 0.034), but not in those with higher alcohol intake (P ¼ 0.448). Conclusions: Dietary TAC is an independent predictor of plasma b-carotene, especially in moderate alcohol drinkers. This may explain, at least in part, the inverse relationship observed between plasma b-carotene and risk of chronic diseases associated to high levels of oxidative stress (i.e., diabetes and CVD), as well as the failure of b-carotene supplements alone in reducing such risk. Contributors: SV participated in the study design and the collection of clinical data, performed the statistical analysis and was the primary writer of the paper, but received input from all the other authors. DDR contributed to the preparation of the paper, to laboratory analysis and to the study design. NP provided expert advice and was involved in paper editing and data interpretation. DA and LF participated in subjects' recruitment and management, in the collection and interpretation of clinical data and in the discussion of the paper. PMP and SS were involved in laboratory analysis and quality control. PR carried out the analysis of plasma b-carotene and provided expert advice on data interpretation. DDR, NP, SS and FB were responsible for the collection, completeness and interpretation of dietary data. IZ was responsible for ethical approval and subjects' recruitment. IZ and FB were responsible for the study concept and design and for sec...

Intervention study with a high or low antioxidant capacity diet: effects on circulating β-carotene

“…The present intervention confirms the previous cross-sectional observation that the TAC of the diet is an important determinant of plasma b-carotene concentrations regardless of b-carotene intake (Valtueña et al, 2007).…”

“…Total antioxidant capacity (TAC) of the diet, which describes the ability of the different antioxidants (independent of their bioavailability) present in food and beverages in scavenging preformed free radicals, was strongly associated to higher plasma concentrations of b-carotene in free living participants, independent of b-carotene intake, and other relevant dietary and clinical confounders (Valtueña et al, 2007). To confirm this observation, we conducted a cross-over intervention study investigating the extent of changes in circulating carotenoids (and particularly b-carotene) as result of two dietary strategies designed to be quantitatively comparable in b-carotene, fruits, vegetables, dietary fibre and alcohol intake, but remarkably different regarding their TAC content.…”

Dietary Total Antioxidant Capacity: A Novel Indicator of Diet Quality in Healthy Young Adults

“…Thus, DQIR has been associated with circulating b-carotene, among other plasma antioxidants, in men [2]. In this sense, dietary TAC has been related to prediction of circulating levels of b-carotene [47]. The association between dietary TAC and Mediterranean hypothesis-oriented dietary scores could thus be explained by the assumed features of the Mediterranean dietary pattern, which combines abundant plant foods (fruits, vegetables, cereals, nuts, seeds, wine, and olive oil) with a large potential amount of active dietary antioxidants [48].…”

Dietary antioxidant capacity and concentration of adiponectin in apparently healthy adults: the ATTICA study

“…The recently developed concept of total dietary antioxidant capacity (Brighenti et al, 2005) overcomes this limitation by summarizing the capacity of different food antioxidants in scavenging free radicals. Indeed, existing studies have revealed an inverse association of total dietary antioxidant capacity with C-reactive protein (CRP) (Brighenti et al, 2005), gastric cancer (Serafini et al, 2002) and total mortality (Agudo et al, 2007), as well as a positive relation with plasma b-carotene (Brighenti et al, 2005;Valtuena et al, 2007), which substantiates the value of this new dietary variable as a useful tool for the investigation of diet-disease relations in the epidemiological field.…”