Beta-carotene is a pigment found in plants like sweet potatoes, carrots, leafy greens, etc.[1] It is also available as a dietary supplement. Because beta-carotene is a provitamin A carotenoid, it is converted to vitamin A in the intestine when ingested.[1]
Observational studies show that higher dietary intake of beta-carotene is associated with improved cognitive function[2] and a lower incidence of depression,[3] osteoporosis,[4] and bone fractures.[5] Observational studies also show that a higher beta-carotene concentration in the blood is associated with improved cognitive function[2] and a lower incidence of metabolic syndrome.[6] However, these studies use cross-sectional or cohort study designs, and beta-carotene intake data is estimated from food frequency questionnaires. Furthermore, randomized controlled trials examining many of these outcomes are lacking, making it difficult to draw firm conclusions. That said, evidence from randomized controlled trials shows that supplementation with beta-carotene has no beneficial effect on cognitive function,[2] nor does it have any effect on the risk of cardiovascular disease, the risk of cancer, or associated mortality.[7][8][9] Some evidence even shows that supplementation with beta-carotene might increase the risk of lung cancer, particularly in smokers.[8][9] Consequently, the causal effects of beta-carotene intake on disease risk/prevention are mixed, and high-quality dose-response randomized controlled trials will be needed before firm conclusions can be made.
References
- ^Bohn T, Desmarchelier C, El SN, Keijer J, van Schothorst E, Rühl R, Borel Pβ-Carotene in the human body: metabolic bioactivation pathways - from digestion to tissue distribution and excretion.Proc Nutr Soc.(2019-Feb)
- ^Diana Marisol Abrego-Guandique, Maria Luisa Bonet, Maria Cristina Caroleo, Roberto Cannataro, Paola Tucci, Joan Ribot, Erika CioneThe Effect of Beta-Carotene on Cognitive Function: A Systematic ReviewBrain Sci.(2023 Oct 17)
- ^Yi Zhang, Jun Ding, Jieyu LiangAssociations of Dietary Vitamin A and Beta-Carotene Intake With Depression. A Meta-Analysis of Observational StudiesFront Nutr.(2022 Apr 25)
- ^Sa Sa Gao, Yongfang ZhaoThe effects of β-carotene on osteoporosis: a systematic review and meta-analysis of observational studiesOsteoporos Int.(2022 Nov 16)
- ^Tesfaye Getachew Charkos, Yawen Liu, Kemal Sherefa Oumer, Ann M Vuong, Shuman YangEffects of β-carotene intake on the risk of fracture: a Bayesian meta-analysisBMC Musculoskelet Disord.(2020 Oct 31)
- ^Beydoun MA, Chen X, Jha K, Beydoun HA, Zonderman AB, Canas JACarotenoids, vitamin A, and their association with the metabolic syndrome: a systematic review and meta-analysis.Nutr Rev.(2019-Jan-01)
- ^Jiaqi Yang, Yulin Zhang, Xiaona Na, Ai Zhaoβ-Carotene Supplementation and Risk of Cardiovascular Disease: A Systematic Review and Meta-Analysis of Randomized Controlled TrialsNutrients.(2022 Mar 18)
- ^Zhang Y, Yang J, Na X, Zhao AAssociation between β-carotene supplementation and risk of cancer: a meta-analysis of randomized controlled trials.Nutr Rev.(2023-Jan-28)
- ^Corbi G, Ali S, Intrieri M, Modaferri S, Calabrese V, Davinelli S, Scapagnini GAssociation Between Beta-Carotene Supplementation and Mortality: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.Front Med (Lausanne).(2022)