Caffeine is not formally “addictive”
Coffee and/or tea use are not addictive in the same way that tobacco use, drugs or heavy alcohol use are considered addictive. Prolonged use of caffeine will typically create a physical dependency, but that does not constitute an addiction, formally speaking.
Addiction is a state characterized by compulsive engagement in rewarding stimuli, despite adverse consequences. (wikipedia Addiction)
Long-term caffeine use can lead to mild physical dependence. A withdrawal syndrome characterized by drowsiness, irritability, and headache typically lasts no longer than a day. True compulsive use of caffeine [i.e. addiction] has not been documented. (citation from Caffeine dependence wikipedia article, square brackets mine) Malenka RC, Nestler EJ, Hyman SE (2009). “Chapter 15: Reinforcement and Addictive Disorders”. In Sydor A, Brown RY. Molecular Neuropharmacology: A Foundation for Clinical Neuroscience (2nd ed.). New York: McGraw-Hill Medical. p. 375.
For further clarification on the issue, see the Diagnostic and Statistical manual of mental disorders (DSM-5) pdf. In particular, note that caffeine use is not recognized as a “Substance use disorder” in “Table 1, Diagnoses associated with substance class” (pg 482).
I am fine if people talk about caffeine being “addictive” colloquially, but formally it is not addictive, even though it may produce a mild physical dependency.
Current research suggests that coffee is mostly health-promoting
I scanned all recent reviews in pubmed on coffee. This seems to be the concensus:
Coffee and tea can generally be recommended as health-promoting additions to an adult diet. (Curr Opin Clin Nutr Metab Care. 2013 Nov;16(6):688-97)
Here are some examples:
“Coffee and caffeine consumption and depression: A meta-analysis of observational studies.” 2015. pubmed
Coffee and caffeine consumption were significantly associated with decreased risk of depression.
“Coffee consumption and risk of fractures: a systematic review and dose-response meta-analysis.” 2014. pubmed
Our meta-analysis suggests that daily consumption of coffee is associated with an increased risk of fractures in women and a contrasting decreased risk in men.
“Coffee and liver health.” 2014. pubmed
Over the past 20 years, an increasing number of epidemiological and experimental studies have demonstrated the positive effects of coffee on chronic liver diseases.
“Coffee and cancer risk, epidemiological evidence, and molecular mechanisms.” 2014. pubmed
Although early studies suggested that coffee consumption might increase risk of some cancers, more comprehensive epidemiological and experimental data now generally indicate either neutral or beneficial effects.
“Effects of coffee on type 2 diabetes mellitus.” 2014. pubmed
Overall, the experimental and epidemiologic evidences presented here elucidate the protective effects of coffee consumption on T2DM, involving multiple preventive mechanisms. Despite the firm evidences available through a growing literature base, it is still uncertain whether the use of coffee should be recommended to patients with diabetes and/or any patient who might be at the risk of T2DM as a supplementary therapy to prevent further progression of T2DM.
“Long-Term Coffee Consumption and Risk of Cardiovascular Disease: A Systematic Review and a Dose-Response Meta-Analysis of Prospective Cohort Studies. 2014.” http://www.ncbi.nlm.nih.gov/pubmed/24201300
Moderate coffee consumption was inversely significantly associated with CVD risk, with the lowest CVD risk at 3 to 5 cups/d, and heavy coffee consumption was not associated with elevated CVD risk.
“Coffee consumption and total mortality: a meta-analysis of twenty prospective cohort studies.” 2014. pubmed
Our findings indicate that coffee consumption is associated with a reduced risk of total mortality.
“Current evidence for the use of coffee and caffeine to prevent age-related cognitive decline and Alzheimer’s disease.” 2014. pubmed
… Some studies suggest a protective association while others report no benefit. … it is critically important to validate potential prevention strategies such as coffee and caffeine.
“Coffee and tea: perks for health and longevity?” 2013. pubmed
Habitual coffee consumption in large epidemiological studies is associated with reduced mortality, both for all-cause and cardiovascular deaths. In addition, coffee intake is associated with risks of heart failure, stroke, diabetes mellitus and some cancers in an inverse dose-dependent fashion. Surprisingly, coffee is associated with neutral to reduced risks for both atrial and ventricular arrhythmias. However, caffeine at high doses can increase anxiety, insomnia, calcium loss and possibly the risk of fractures…Coffee … can generally be recommended as health-promoting additions to an adult diet…
So, where did the idea come from that coffee is so harmful (outside of an LDS context)?
The idea that coffee is a dangerous, addictive stimulant springs mostly from 1970s- and 1980s-era studies that tied the drink to higher rates of cancer and heart disease, explains Dr. Rob van Dam, a disease and nutrition expert at Harvard School of Public Health who has examined coffee and its health effects. According to van Dam, that old research didn’t do a great job of adjusting for a person’s cigarette habit or other unhealthy behaviors. source