Which Sources of Flavonoids: Complex Diets or Dietary Supplements?

Abstract

There is increasing interest in the potential health benefits of dietary flavonoids. Fruits and vegetables, tea, and cocoa are rich natural sources of flavonoids. Epidemiological studies have indicated that consumption of these foods is likely to be associated with a reduced risk of cardiovascular disease, but the etiology of this benefit is not yet clearly defined. Furthermore, in some acute interventions, a positive effect of tea and cocoa on vascular function has been reported. An alternative source of flavonoids is dietary supplements, which have become increasingly popular in the recent past. In this context, it needs to be critically evaluated whether vascular health-promoting and other positive properties of flavonoid-rich diets can be replaced by purified flavonoids as dietary supplements. Plant sources of flavonoids contain a complex mixture of secondary plant metabolites and not only flavonoids per se. This complex mixture of secondary plant metabolites cannot be simply exchanged by single purified compounds as dietary supplements. If flavonoids are given as dietary supplements, toxicity issues as well as nutrient drug interactions need to be taken into account. Purified flavonoids given in high doses as dietary supplements may affect trace element, folate, and vitamin C status. Furthermore, they may exhibit antithyroid and goitrogenic activities. In this review article, the available literature on the safety issues surrounding high dose supplemental flavonoid consumption has been summarized.

Consumption of anthocyanin-rich cherry juice for 12 weeks improves memory and cognition in older adults with mild-to-moderate dementia

“…Although under-researched in humans, some pre-clinical evidence indicates that high-doses of flavonoids may inhibit ascorbate absorption (39), which may explain the reduction in serum vitamin C. Alternatively, the reagents that were utilized to prepare the serum prior to Vitamin C analysis may have degraded over the study period.…”

Detection of Total Flavenoids, Reductive Ability, and Anti-microbial in Glycyrrhiza and Achillea Medicinal Plants

“…The flavenoids have an interest as dietary constituents; however in clinical studies indicate their roles in preventing cardiovascular disease and many kinds of cancer (Chu, Y. H. & et al, 2000). In other studies flavenoids and phenolics compounds have an efficient free radical scavenger activity besides some lipid peroxides ISSN 2157-6076 2017 inhibitors (Egert, S. & Rimbach, G. , 2011). Therefore, increasing flavenoids in both plants may be attributing to the increasing of reductive abilities of these plants (Franco, M. N. & et al, 2014).…”

Características nutricionales y antioxidantes de la fruta curuba larga (Passiflora mollissima Bailey)

“…Los principales flavonoides incluyen a las antoncianinas presentes en grandes cantidades en bayas, tales como los arándanos, flavonoles presentes en frutos, vegetales y flores, flavonas en perejil y tomillo, flavanonas en cítricos, isoflavonas en soya y flavonoles mono y poliméricos, tales como las catequinas en té, proantocianidinas en las bayas, el vino y el chocolate (40). En las pasifloras los flavonoides más frecuentes son los c-glicosil flavonoides, encontrándose con mayor frecuencia orientina, isoorientina, vitexina e isovitexina, concordando con los reportes de Zucolotto (41), quien encontró en las hojas y el pericarpio de la curuba larga gran diversidad de flavonoides; identificándose en las hojas principalmente isovitexina, orientina, vitexina, 4-metoxiluteolina-8-c6-acetilglucopiranosido, isoorientina, swertisina y vicenina; mientras en el pericarpio se encontró isoorientina, orientina e isovitexina.…”