Caffeine—The World’s Greatest Psychoactive Addiction

Continuing on through ground water and drinking water contaminants I decided to write a post about what is almost certainly the most interesting and ubiquitous human induced contaminant….caffeine. Most people probably never think of caffeine as a natural contaminant, however anytime a substance is introduced into the environment in new places it is going to have a reaction with the system that is already there. Caffeine is no exception. Although, it does seem to be an exception to almost everything else…

For instance, although caffeine is a psychoactive stimulant it is one of the only psychoactive substances that humans regularly consume that is unregulated. Almost everyone intakes caffeine right? Many of us can’t wake up in the morning without our cup. A recent study found that women consuming 200 mg or more per day are twice as likely to miscarriage¹. However, another study found no correlation¹.

Caffeine is a natural pesticide which protects plants from feeding insects. It acts to paralyze and kill certain insects. Its effects on humans are broad and not commonly understood. It is mainly a central nervous system stimulant which, as we all know, helps keep us awake and alert. Caffeine is also a diuretic…yep…it makes your body produce urine faster. It has a half life in most human adults of 3 to 4 hours². Caffeine is found in a variety of foods and drinks such as coffee, teas, mate, and soft drinks.

Caffeine is metabolized by your liver to³:

• Paraxanthine (84%)-Has similar effects to caffeine
• Theobromine (12%)-Used in the past as treatment for edema, syphilitic angina, hypertension, and vascular diseases⁴.
• Theophylline (4%)-Used in the past as a respiratory drug for asthma

Caffeine is nearly ubiquitous in natural waters. Several studies have measured the amount of caffeine and its metabolites in surface and ground waters across the world^5,6,7. It is an excellent method to track anthropomorphic effects on the environment because caffeine is almost always introduced into the environment in quantity by humanity.

Caffeine has multiple effects on wildlife and on the geochemistry of water systems. The total effects of caffeine are as yet unknown, but certainly it is one of the most pervasive geochemical pollutants on the planet.

 

1. Rubin, Rita (2008-01-20). New studies, different outcomes on caffeine, pregnancy (English). USA TODAY.

2. Meyer, FP; Canzler E, Giers H, Walther H. (1991). “Time course of inhibition of caffeine elimination in response to the oral depot contraceptive agent Deposiston. Hormonal contraceptives and caffeine elimination”. Zentralbl Gynakol 113 (6): 297-302. PMID 2058339

3. The Pharmacogenetics and Pharmacogenomics Knowledge Base. http://www.pharmgkb.org/do/serve?objId=464&objCls=DrugProperties#biotransformationData

4. Kelly, Caleb J (August 2005). “Effects of theobromine should be considered in future studies”. American Journal of Clinical Nutrition 82 (2).

5. Determination of pharmaceutical compounds in surface- and ground-water samples by solid-phase extraction and high-performance liquid chromatography-electrospray ionization mass spectrometry, J. D. Cahill, E. T. Furlong, M. R. Burkhardt, D. Kolpin and L. G. Anderson; Journal of Chromatography A, Volume 1041, Issues 1-2, 2 July 2004, Pages 171-180

6. Drugs and personal care products as ubiquitous pollutants: occurrence and distribution of clofibric acid, caffeine and DEET in the North Sea ;Stefan Weigel, Jan Kuhlmann and Heinrich Hühnerfuss; The Science of The Total Environment, Volume 295, Issues 1-3, 5 August 2002, Pages 131-141

7. Tracking persistent pharmaceutical residues from municipal sewage to drinking water; Thomas Heberer; Journal of Hydrology, Volume 266, Issues 3-4, 15 September 2002, Pages 175-189

8. Caffeine and Pharmaceuticals as Indicators of Waste Water Contamination in Wells; Ralph L. Seiler^aaU.S. Geological Survey, 333 W. Nye Lane, Carson City, NV 89706. (702) 887-7674 (voice); (702) 887-7629 (fax). E-mail: rseiler@usgs.gov., Steven D. Zaugg^bbU.S. Geological Survey National Water Quality Laboratory, Box 25046, MS-407, Denver Federal Center, Denver, CO 80225, James M. Thomas^aaU.S. Geological Survey, 333 W. Nye Lane, Carson City, NV 89706. (702) 887-7674 (voice); (702) 887-7629 (fax). E-mail: rseiler@usgs.gov., and Darcy L. Howcroft; Ground Water; Volume 37 Issue 3 Page 405-410, May 1999

9. Caffeine as an environmental indicator for assessing urban aquatic ecosystems; Cadernos de Saúde Pública; Print ISSN 0102-311X; Cad. Saúde Pública vol.21 no.6 Rio de Janeiro Nov./Dec. 2005