TY - JOUR
T1 - β-carotene
T2 - A cancer chemopreventive agent or a co-carcinogen?
AU - Paolini, Moreno
AU - Abdel-Rahman, Sherif Z.
AU - Sapone, Andrea
AU - Pedulli, Gian Franco
AU - Perocco, Paolo
AU - Cantelli-Forti, Giorgio
AU - Legator, Marvin S.
N1 - Funding Information:
This work was supported by a Ministry of Instruction, University and Research of Italy (MIUR) grant and, in part, by Philip Morris Inc. We are grateful to Dr. Marinel M. Ammenheuser and Robin M.T. Cooke for editing.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2003/6
Y1 - 2003/6
N2 - Evidence from both epidemiological and experimental observations have fueled the belief that the high consumption of fruits and vegetables rich in carotenoids may help prevent cancer and heart disease in humans. Because of its well-documented antioxidant and antigenotoxic properties, the carotenoid β-carotene (βCT) gained most of the attention in the early 1980s and became one of the most extensively studied cancer chemopreventive agents in population-based trials supported by the National Cancer Institute. However, the results of three randomized lung cancer chemoprevention trials on βCT supplementation unexpectedly contradicted the large body of epidemiological evidence relating to the potential benefits of dietary carotenoids. Not only did βCT show no benefit, it was associated with significant increases in lung cancer incidence, cardiovascular diseases, and total mortality. These findings aroused widespread scientific debate that is still ongoing. It also raised the suspicion that βCT may even possess co-carcinogenic properties. In this review, we summarize the current data on the co-carcinogenic properties of βCT that is attributed to its role in the induction of carcinogen metabolizing enzymes and the over-generation of oxidative stress. The data presented provide convincing evidence of the harmful properties of this compound if given alone to smokers, or to individuals exposed to environmental carcinogens, as a micronutrient supplement. This has now been directly verified in a medium-term cancer transformation bioassay. In the context of public health policies, while the benefits of a diet rich in a variety of fruits and vegetables should continue to be emphasized, the data presented here point to the need for consideration of the possible detrimental effects of certain isolated dietary supplements, before mass cancer chemoprevention clinical trials are conducted on human subjects. This is especially important for genetically predisposed individuals who are environmentally or occupationally exposed to mutagens and carcinogens, such as those found in tobacco smoke and in industrial settings.
AB - Evidence from both epidemiological and experimental observations have fueled the belief that the high consumption of fruits and vegetables rich in carotenoids may help prevent cancer and heart disease in humans. Because of its well-documented antioxidant and antigenotoxic properties, the carotenoid β-carotene (βCT) gained most of the attention in the early 1980s and became one of the most extensively studied cancer chemopreventive agents in population-based trials supported by the National Cancer Institute. However, the results of three randomized lung cancer chemoprevention trials on βCT supplementation unexpectedly contradicted the large body of epidemiological evidence relating to the potential benefits of dietary carotenoids. Not only did βCT show no benefit, it was associated with significant increases in lung cancer incidence, cardiovascular diseases, and total mortality. These findings aroused widespread scientific debate that is still ongoing. It also raised the suspicion that βCT may even possess co-carcinogenic properties. In this review, we summarize the current data on the co-carcinogenic properties of βCT that is attributed to its role in the induction of carcinogen metabolizing enzymes and the over-generation of oxidative stress. The data presented provide convincing evidence of the harmful properties of this compound if given alone to smokers, or to individuals exposed to environmental carcinogens, as a micronutrient supplement. This has now been directly verified in a medium-term cancer transformation bioassay. In the context of public health policies, while the benefits of a diet rich in a variety of fruits and vegetables should continue to be emphasized, the data presented here point to the need for consideration of the possible detrimental effects of certain isolated dietary supplements, before mass cancer chemoprevention clinical trials are conducted on human subjects. This is especially important for genetically predisposed individuals who are environmentally or occupationally exposed to mutagens and carcinogens, such as those found in tobacco smoke and in industrial settings.
KW - Cancer
KW - Chemopreventive agent
KW - β-Carotene
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U2 - 10.1016/S1383-5742(03)00002-4
DO - 10.1016/S1383-5742(03)00002-4
M3 - Article
C2 - 12787812
AN - SCOPUS:0037674659
SN - 1383-5742
VL - 543
SP - 195
EP - 200
JO - Mutation Research - Reviews in Mutation Research
JF - Mutation Research - Reviews in Mutation Research
IS - 3
ER -