Coffee is the most consumed beverage in the world. A naturally derived compound, caffeine is found in coffee beans, tea leaves, cacao plants and nuts and seeds of numerous plants . With a long history of use as a mild stimulant, caffeine is a common consumed in varying amounts from coffee, tea, cola and energy drinks, supplements and other caffeinated products .
Here’s the good and the bad on coffee and your health.
Good News First: Coffee Is A Hell Of A Drug
Caffeine influences the central nervous system and this is thought to benefit brain function, increase alertness and improve mood. Numerous studies are also suggesting a link in caffeine consumption and its protective qualities for brain function and correlation in the decrease likelihood of depression [4-6].
Caffeine may boost metabolism and promote fat loss, but these effects are likely to remain small over the long term [7,8]. Recent studies have investigated the benefit of consuming caffeinated beverages like coffee and tea in reducing the risk of heart disease and type 2 diabetes, although this appears to vary on the individual [9,10].
If A Little Bit Is Good Then A Lot Is Great Right?
Whilst not recommended for your evening yoga session, consuming a small amount of caffeine before exercise may improve exercise performance. The main performance benefits of caffeine appear to come from its influence on brain function, resulting in the reduced perception of effort and/or reduced perception of fatigue .
Individual responses to caffeine vary but typically doses in the range 1-3 mg caffeine per kg body weight are sufficient to provide its benefits and improve physical performance.
This is 60-180mg of caffeine for a 60kg yoga practitioner.
Recent research indicates that lower doses can provide similar performance benefits as the higher doses .
A standard cup of tea contains less than half the amount of caffeine of a typical cup of instant coffee - one cup of tea contains around 10-50mg of caffeine and a cup of instant coffee contains between 60-120mg per 250ml cup . When served without milk or sugar, tea and coffee contain virtually no kilojoules.
Coffee Is Not For Everybody
Despite the benefits the potential negative effects of excessive caffeine intake must be considered, particularly in children and pregnant women.
Caffeine can have negative side effects in some people and in large doses, may experience:
Anxiety, restlessness and over-arousal
Increased heart rate and palpitations
Headaches and migraines
Impaired fine motor control
Whilst there is currently no recognised health-based guidance value for caffeine, Food Standards Australia New Zealand (FSANZ) recognizes the evidence of increased anxiety levels in children at doses of about 3 mg of caffeine per kilogram of bodyweight per day. The anxiety level for children aged 5-12 equates to a caffeine dose of 95 mg per day (approximately two cans of cola) and about 210 mg per day (approximately three cups of instant coffee) for adults [2,11].
The effects of coffee for each individual varies and growing evidence correlates an individual’s genetic makeup to the rate at which caffeine is metabolized .
“Slow” metabolisers of caffeine don’t process caffeine effectively and these people who are adversely affected by caffeine.
Others who get a boost after intake are considered “fast” metabolisers of caffeine.
The Price Of Coffee Isn’t Physical
Caffeine is not as ‘bad’ for the body as we had once believed, the evidence shows that it may be just the opposite. Whether coffee is good or bad for your health depends on how well you metabolize caffeine. Coffee does has a significant environmental and social impact with it’s high water usage and sometimes questionsable use of labour so there are ethical concerns outside the physical impact of coffee to consider.
 Heckman, M., Weil, J., & de Mejia, E. (2010). Caffeine (1, 3, 7-trimethylxanthine) in foods: A comprehensive review on consumption, functionality, safety, and regulatory matters. Journal of Food Science, 75(3), R77-R87. doi:10.1111/j.1750-3841.2010.01561.x
 Food Standards Australia New Zealand. Caffeine [internet] [cited 2016 Sep 2016]. Available from: http://www.foodstandards.gov.au/consumer/generalissues/Pages/Caffeine.aspx
 Sports Dietitians Australia. Caffeine [internet] [cited 2016 Sep 2016]. Available from: https://www.sportsdietitians.com.au/factsheets/supplements/caffeine/
 Grosso, G., Micek, A., Castellano, S., Pajak, A., & Galvano, F. (2016). Coffee, tea, caffeine and risk of depression: A systematic review and dose–response meta‐analysis of observational studies. Molecular Nutrition & Food Research, 60(1), 223-234. doi:10.1002/mnfr.201500620
 Heatherley, S., Hayward, R., Seers, H., & Rogers, P. (2005). Cognitive and psychomotor performance, mood, and pressor effects of caffeine after 4, 6 and 8 h caffeine abstinence. Psychopharmacology, 178(4), 461-470. doi:10.1007/s00213-004-2159-9
 Carman, A., Dacks, P., Lane, R., Shineman, D., & Fillit, H. (2014). Current evidence for the use of coffee and caffeine to prevent age-related cognitive decline and alzheimer's disease. Journal of Nutrition Health & Aging, 18(4), 383-392. doi:10.1007/s12603-014-0021-7
 Rudelle, S., Ferruzzi, M. G., Cristiani, I., Moulin, J., Macé, K., Acheson, K. J., & Tappy, L. (2007). Effect of a thermogenic beverage on 24-hour energy metabolism in humans. Obesity, 15(2), 349-355. doi:10.1038/oby.2007.529
 Lopez-Garcia, E., Van Dam, R. M., Rajpathak, S., Willett, W. C., Manson, J. E., & Hu, F. B. (2006). Changes in caffeine intake and long-term weight change in men and women. American Journal of Clinical Nutrition, 83(3), 674-680.
 Wu, J., Ho, S. C., Zhou, C., Ling, W., Chen, W., Chen, Y., & Wang, C. (2009). Coffee consumption and risk of coronary heart diseases: A meta-analysis of 21 prospective cohort studies. International Journal of Cardiology, 137(3), 216-225. doi:10.1016/j.ijcard.2008.06.051
 Jiang, X., Zhang, D., & Jiang, W. (2014). Coffee and caffeine intake and incidence of type 2 diabetes mellitus: A meta-analysis of prospective studies. European Journal of Nutrition, 53(1), 25-38. doi:10.1007/s00394-013-0603-x
 Dietitians Association of Australia. Regulation of Caffeine in Foods. [internet] [cited 2016 Jul 2016]. Available from: http://daa.asn.au/wp-content/uploads/2013/10/DAA-submission-Caffeine-Options-Paper.pdf
 The Guardian. Sustainable Business. Water usage and coffee [internet] [cited 2016 Jul 2016]. Available from: https://www.theguardian.com/sustainable-business/water-use-coffee-sustainable-profitable