Caffeine, an alkaloid compound scientifically known as 3,7-dihydro-1,3,7-trimethyl-1H-purine-2,6,-dione, occurs naturally in the coffee bean. You ingest caffeine in varying amounts whenever you drink a beverage brewed from the ground bean, even if it has been decaffeinated. Unless you drink 80 to 100 cups of coffee in quick succession, caffeine won't reach a lethal dose. At smaller doses, it can increase alertness and cause insomnia.
Size
The dose of caffeine available in coffee depends on the brewing technique and amount, notes a literature review by Bruce A. Goldberger and colleagues at the University of Florida Departments of Psychiatry, Neuroscience, Community Health and Family Medicine. Generic brewed coffee contains about 133 milligrams of caffeine per 8-ounce cup and 266 mg per 16-oz. cup, according to the Center for Science in the Public Interest. The range, depending on brand, runs from 102 to 200 mg per 8 oz.
Types
That 16-oz. cup of coffee you get from chain establishments contains 143 to 206 mg of caffeine, according to CSPI. Starbucks' 16-oz. grande brewed coffee contains 320 mg, while the Einstein Bros. version contains 300 mg and Dunkin' Donuts' 206 mg. A 16-oz. Starbucks Vanilla Latte contains 150 mg, while its Frappuccino Blended Coffee contains an average of 115 mg per 9.5 oz. Instant coffee packs a range of 27 to 173 mg per 8 oz., with 93 mg the average.
Features
Espresso contains less caffeine overall but more per ounce, according to CSPI, which found 75 mg in 1-oz. shots from Starbucks and Einstein Bros. Starbucks' doppio contains 150 mg in its 2-oz. serving. Generic espresso runs between 30 and 90 mg per ounce, with an average of 40 mg.
Considerations
If you want to limit your intake of caffeine, you can switch to decaffeinated coffee, which still contains small amounts of the compound. Generic decaffeinated coffee contains 5 mg per 8 oz., with a range of 3 mg to 12 mg. Starbucks' decaf espresso contains 4 mg in its 1-oz. serving.
Warning
The average American consumes 291 mg of caffeine daily, Goldberger notes, the equivalent of two cups of generic 8 oz. coffee. A daily intake of 1,000 mg can induce psychiatric symptoms in healthy adults and children, so monitoring coffee intake and overall caffeine consumption in psychiatric patients and those who suffer from anxiety is warranted.
References
- Neuroscience for Kids: Effects of Caffeine on the Nervous System
- University of Florida College of Medicine: Evaluation of Current Caffeine Content of Coffee Beverages
- Center for Science in the Public Interest: Caffeine Content of Food & Drugs
- Mayo Clinic: Caffeine Content for Coffee, Tea, Soda and More
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