Kaféin
Kaféin atawa nyaéta hiji sanyawa alkaloid stimulan psikoaktif, kapanggih ku kimiawan Jérman Friedrich Ferdinand Runge taun 1819 (anjeunna ngistilahkeun kaffein, zat kimia anu aya dina kopi). Ieu zat téh ogé bagian tina campuran kimia guaranin nu aya dina guarana, matéin nu aya dina maté, jeung téin nu aya dina entéh; kabéhanana ngandung alkaloid lian kayaning téofilin jeung téobromin, stimulan jantung.

Kaféin dikandung dina kacang/siki, daun, jeung buah kalawan kadar anu béda-béda. Gunana taya lian pikeun péstisida alami nu maralisis jeung bisa maéhan serangga nu ngahakan éta tutuwuhan. Sumber kaféin pikeun manusa biasana diala tina ékstrak siki kopi jeung daun Camellia sinensis, sarta kadaharan/inuman nu ngandung produk turunan siki kola.

Pikeun awak manusa, kaféin téh stimulan sistem saraf puseur, nu balukarna sacara samentara bisa ngaleungitkeun rasa tunduh sarta ngaronjatkeun kawaspadaan. Kiwari, kaféin jadi zat psikoaktif nu panglobana dikonsumsi, utamana ku sabab ieu zat mah teu dicaram konsumsina. Di Amérika Kalér, unggal poé 90% sawawa ngonsumsi kaféin. Badan POM AS (FDA) ngadaptar kaféin salaku "multiple purpose generally recognized as safe food substance" (zat kadaharan multiguna nu sacara umum aman).

Kaféin mibanda pasipatan diurétik, sahanteuna mun dibikeun ka nu teu toléran obat kalawan dosis anu cukup. Sabalikna, pikeun nu geus biasa ngonsumsi mah toléransina beuki luat, sarta teu ngabalukarkeun déhidrasi

Rujukan

Tumbu kaluar

Émbaran umum 
 How Stuff Works: "How Caffeine Works"
 Erowid Caffeine Vaults
 Highly Caffeinated: The Caffeine Information Archive"
 National Geographic January 2005: Caffeine
 Caffeine Zone: Social and Medical info on caffeine and its effects. 
 Naked Scientists Online: Why do plants make caffeine?
 The Physician and Sportsmedicine: Caffeine: A User's Guide
 The Consumers Union Report on Licit and Illicit Drugs, Caffeine-Part 1 Part 2
 Coffee: A Little Really Does Go a Long Way, NPR, September 28, 2006
 Does coffee really give you a buzz? by John Triggs in the Daily Express April 17 2007
 Caffeine: ChemSub Online
 How much caffeine is in your daily habit? (Caffeine content in common foods and drinks) by Mayo Clinic Staff October 2007
 How to determine caffeine in decaffeinated coffee by NIR spectroscopy

Warta 
 Alcohol and Drugs History Society: Caffeine news page
 National Post: Caffeine linked to psychiatric disorders
 Caffeine Withdrawal Recognized as a Disorder

Kawaluyaan 
 Is Caffeine a Health Hazard?
 eMedicine Caffeine-Related Psychiatric Disorders
 Protects brain from Alzheimer's?

Kaféin
Kopi