Antioksidan: Perbedaan antara revisi
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=== Hubungan dengan diet ===
Meskipun beberapa tingkat vitamin antioksidan dalam diet diperlukan demi kebugaran, masih ada keraguan besar benarkah suplemen antioksidan memiliki aktivitas anti-penyakit; dan jika mereka benar-benar menguntungkan, antioksidan apa yang diperlukan dan berapa jumlahnya.<ref name="Stanner">{{cite|author1=Stanner SA|author2=Hughes J|author3=Kelly CN|author4=Buttriss J|date=May 2004|title=A review of the epidemiological evidence for the 'antioxidant hypothesis'|journal=Public Health Nutrition|volume=7|issue=3|pages=407–22|doi=10.1079/PHN2003543|PMID=15153272}}</ref><ref name="Shenkin">{{cite|author1 = Shenkin A|date = Feb 2006|title = The key role of micronutrients|journal = Clinical Nutrition|volume = 25|issue = 1|pages = 1–13|doi = 10.1016/j.clnu.2005.11.006|PMID = 16376462}}</ref><ref name="Woodside">{{cite|author1=Woodside JV|author2=McCall D|author3=McGartland C|author4=Young IS|date=Nov 2005|title=Micronutrients: dietary intake v. supplement use|journal=The Proceedings of the Nutrition Society|volume=64|issue=4|pages=543–53|doi=10.1079/PNS2005464|PMID=16313697}}</ref> Memang, beberapa penulis berpendapat bahwa hipotesis yang mengatakan antioksidan dapat mencegah penyakit kronis<ref name="Stanner"/><ref name="WCRF">[http://www.dietandcancerreport.org/?p=ER ''Food, Nutrition, Physical Activity, and the Prevention of Cancer: a Global Perspective.''] [[World Cancer Research Fund]] (2007). ISBN 978-0-9722522-2-5.</ref> kini telah dibantah dan bahwa ide tersebut sesat sejak awal.<ref name="Hail">{{cite|author1=Hail N|author2=Cortes M|author3=Drake EN|author4=Spallholz JE|date=Jul 2008|title=Cancer chemoprevention: a radical perspective|journal=Free Radical Biology & Medicine|volume=45|issue=2|pages=97–110|doi=10.1016/j.freeradbiomed.2008.04.004|PMID=18454943}}</ref> Sebaliknya, [[polifenol]] diet dalam konsentrasi kecil mungkin tidak memiliki peran antioksidan yang dapat mempengaruhi isyarat antar sel, sensitivitas [[Reseptor (biokimia)|reseptor]], aktivitas [[enzim]] inflamasi atau [[regulasi gen]].<ref name="Williams">{{cite|author1=Williams RJ|author2=Spencer JP|author3=Rice-Evans C|date=Apr 2004|title=Flavonoids: antioxidants or signalling molecules?|journal=Free Radical Biology & Medicine|volume=36|issue=7|pages=838–49|doi=10.1016/j.freeradbiomed.2004.01.001|PMID=15019969}}</ref><ref name="Virgili">{{cite|author1=Virgili F|author2=Marino M|date=Nov 2008|title=Regulation of cellular signals from nutritional molecules: a specific role for phytochemicals, beyond antioxidant activity|journal=Free Radical Biology & Medicine|volume=45|issue=9|pages=1205–16|doi=10.1016/j.freeradbiomed.2008.08.001|PMID=18762244}}</ref>
Untuk [[harapan hidup]] secara keseluruhan, telah disarankan bahwa stres oksidatif tingkat sedang dapat memperpanjang umur cacing ''Caenorhabditis elegans'', dengan menginduksi respons pelindung untuk peningkatan tingkat spesies oksigen reaktif.<ref>{{Citation|author1 = Schulz TJ|author2 = Zarse K|author3 = Voigt A|author4 = Urban N|author5 = Birringer M|author6 = Ristow M|date = Oct 2007|title = Glucose restriction extends Caenorhabditis elegans life span by inducing mitochondrial respiration and increasing oxidative stress|journal = Cell Metabolism|volume = 6|issue = 4|pages = 280–93|doi = 10.1016/j.cmet.2007.08.011|pmid = 17908557}}</ref> Sugesti bahwa harapan hidup meningkat berasal dari peningkatan konflik stres oksidatif dengan hasil yang terlihat pada ragi ''[[Saccharomyces cerevisiae]]'',<ref>{{Cite|author1 = Barros MH|author2 = Bandy B|author3 = Tahara EB|author4 = Kowaltowski AJ|date = Nov 2004|title = Higher respiratory activity decreases mitochondrial reactive oxygen release and increases life span in Saccharomyces cerevisiae|journal = The Journal of Biological Chemistry|volume = 279|issue = 48|pages = 49883–8|doi = 10.1074/jbc.M408918200|pmid = 15383542}}</ref> tetapi situasi pada mamalia belum jelas.<ref>{{Cite|author1 = Sohal RS|author2 = Mockett RJ|author3 = Orr WC|date = Sep 2002|title = Mechanisms of aging: an appraisal of the oxidative stress hypothesis|journal = Free Radical Biology & Medicine|volume = 33|issue = 5|pages = 575–86|doi = 10.1016/S0891-5849(02)00886-9|pmid = 12208343}}</ref><ref>{{Cite|author1 = Sohal RS|date = Jul 2002|title = Role of oxidative stress and protein oxidation in the aging process|journal = Free Radical Biology & Medicine|volume = 33|issue = 1|pages = 37–44|doi = 10.1016/S0891-5849(02)00856-0|pmid = 12086680}}</ref><ref>{{Cite|author1 = Rattan SI|date = Dec 2006|title = Theories of biological aging: genes, proteins, and free radicals|journal = Free Radical Research|volume = 40|issue = 12|pages = 1230–8|doi = 10.1080/10715760600911303|pmid = 17090411}}</ref> Namun demikian, suplemen antioksidan tidak terlihat dapat meningkatkan harapan hidup pada manusia.<ref>{{Cite|author1 = Green GA|date = Dec 2008|title = Review: antioxidant supplements do not reduce all-cause mortality in primary or secondary prevention|journal = Evidence-Based Medicine|volume = 13|issue = 6|page = 177|doi = 10.1136/ebm.13.6.177|pmid = 19043035}}</ref>
Meskipun antioksidan telah diteliti mengenai efek potensialnya pada [[penyakit neurodegeneratif]] seperti [[Alzheimer]], [[Penyakit Parkinson|Parkinson]], dan [[sklerosis lateral amiotropik]],<ref>{{Cite|author1 = Di Matteo V|author2 = Esposito E|date = Apr 2003|title = Biochemical and therapeutic effects of antioxidants in the treatment of Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis|journal = Current Drug Targets. CNS and Neurological Disorders|volume = 2|issue = 2|pages = 95–107|doi = 10.2174/1568007033482959|pmid = 12769802}}</ref><ref>{{Cite|author1 = Rao AV|author2 = Balachandran B|date = Oct 2002|title = Role of oxidative stress and antioxidants in neurodegenerative diseases|journal = Nutritional Neuroscience|volume = 5|issue = 5|pages = 291–309|doi = 10.1080/1028415021000033767|pmid = 12385592}}</ref> namun studi-studi ini belum meyakinkan.<ref>{{Cite journal|vauthors = Crichton GE, Bryan J, Murphy KJ|title = Dietary antioxidants, cognitive function and dementia--a systematic review|journal = Plant Foods for Human Nutrition|volume = 68|issue = 3|pages = 279–92|date = Sep 2013|pmid = 23881465|doi = 10.1007/s11130-013-0370-0}}</ref><ref>{{Cite journal|vauthors = Takeda A, Nyssen OP, Syed A, Jansen E, Bueno-de-Mesquita B, Gallo V|title = Vitamin A and carotenoids and the risk of Parkinson's disease: a systematic review and meta-analysis|journal = Neuroepidemiology|volume = 42|issue = 1|pages = 25–38|year = 2014|pmid = 24356061|doi = 10.1159/000355849}}</ref><ref>{{Cite journal|vauthors = Harrison FE|title = A critical review of vitamin C for the prevention of age-related cognitive decline and Alzheimer's disease|journal = Journal of Alzheimer's Disease|volume = 29|issue = 4|pages = 711–26|year = 2012|pmid = 22366772|pmc = 3727637|doi = 10.3233/JAD-2012-111853}}</ref>
== Hal penting mengenai uji antioksidan ==
Antioksidan diharapkan aman dalam penggunaan atau tidak toksik, efektif pada konsentrasi rendah (0,01-0,02%), tersedia dengan harga cukup terjangkau, dan tahan terhadap proses pengolahan produk .<ref name="Oz"/> Antioksidan penting dalam melawan radikal bebas, tetapi dalam [[kapasitas]] berlebih menyebabkan kerusakan sel.<ref name="Oz"/>
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