Caffeine is a bitter substance found in coffee, tea, soft drinks, chocolate, kola nuts, and certain medicines. It has many effects on the body’s metabolism, including stimulating the central nervous system. This can make you more alert and give you a boost of energy.
For most people, the amount of caffeine in two to four cups of coffee a day is not harmful. However, too much caffeine can cause problems. It can
- Make you jittery and shaky
- Make it hard to fall asleep or stay asleep
- Cause headaches or dizziness
- Make your heart beat faster or cause abnormal heart rhythms
- Cause dehydration
- Make you dependent on it so you need to take more of it. If you stop using caffeine, you could get withdrawal symptoms.
Some people are more sensitive to the effects of caffeine than others. They should limit their use of caffeine. So should pregnant and nursing women. Certain drugs and supplements may interact with caffeine. If you have questions about whether caffeine is safe for you, talk with your health care provider.
- Caffeine is a stimulant obtained from over 60 different types of plants worldwide.
- The scientific name for caffeine is 1,3,7-trimethylxanthine.
- Caffeine is considered to be the most commonly used psychoactive drug in the world.
- Coffee, soda, and tea are the most common sources of caffeine in the American diet.
- Discontinuation of regular caffeine use may produce withdrawal symptoms.
- The effects of caffeine persist for about three hours or less.
- Caffeine is found in some combination medications and weight control products.
- The American Medical Association and US Food and Drug Administration consider a moderate intake of caffeine to be “generally recognized as safe.”
Caffeine Side Effects
Caffeine can lead to:
- A fast heart rate
- Difficulty sleeping
- Urinating more often
Stopping caffeine suddenly may cause withdrawal symptoms. These may include:
There has been much research on the health effects of caffeine.
- Large amounts of caffeine may stop the absorption of calcium and lead to thinning bones (osteoporosis).
- Caffeine may lead to painful, lumpy breasts (fibrocystic disease).
Caffeine may harm a child’s nutrition if drinks with caffeine replace healthy drinks such as milk. Caffeine cuts down on appetite so a child who consumes caffeine may eat less. The United States has not developed guidelines for caffeine intake by children.
Is caffeine safe during pregnancy?
There is no disputing the importance of proper nutrition during pregnancy. There is some dispute about the safety of caffeine during this time. One concern is that caffeine may lead to miscarriages. In a study following 431 pregnant women, no relationship between caffeine consumption up to 300 mg/day and adverse pregnancy outcomes was found. Another study examined the relationship between caffeine consumption and spontaneous abortions in over 5,000 women and found no association. A recent study found that caffeine can reach the follicular fluid of the ovaries. It also found that an increase in coffee consumption was associated with an increased number of aborted pregnancies.
On the other side, research has also shown no clear relationship between caffeine intake and fertility and birth defects. Even with this evidence, everyone agrees that there is a limit for how much caffeine can be consumed during pregnancy. The majority of the subjects in the studies were consuming small to moderate amounts of caffeine. It is difficult to accurately test the effects of very high intakes of caffeine without risking the health of the mother and child.. The American College of Obstetricians and Gynecologists recommends a caffeine limit of the equivalent of one to two cups of coffee per day during pregnancy.
|Dunkin’ Donuts Coffee with Turbo Shot||large, 20 fl. oz.||436|
|Starbucks Coffee||venti, 20 fl. oz.||415|
|Starbucks Coffee||grande, 16 fl. oz.||330|
|Panera Frozen Mocha||16.5 fl. oz.||267|
|Starbucks Coffee||tall, 12 fl. oz.||260|
|Starbucks Caffè Americano||grande, 16 fl. oz.||225|
|Panera Coffee||regular, 16.8 fl. oz.||189|
|Starbucks Espresso Frappuccino||venti, 24 fl. oz.||185|
|Dunkin’ Donuts Coffee||medium, 14 fl. oz.||178|
|Starbucks Caffè Mocha||grande, 16 fl. oz.||175|
|Starbucks Iced Coffee||grande, 16 fl. oz.||165|
|Maxwell House Ground Coffee—100% Colombian, Dark Roast, Master Blend, or Original Roast||2 Tbs., makes 12 fl. oz.||100-160|
|Dunkin’ Donuts Cappuccino||large, 20 fl. oz.||151|
|Starbucks—Caffè Latte, Cappuccino, or Caramel Macchiato||grande, 16 fl. oz.||150|
|Starbucks Espresso||doppio, 2 fl. oz.||150|
|Keurig Coffee K-Cup, all varieties||1 cup, makes 8 fl. oz.||75-150|
|Folgers Classic Roast Instant Coffee||2 tsp., makes 12 fl. oz.||148|
|Starbucks Doubleshot Energy Coffee, can||15 fl. oz.||146|
|Starbucks Mocha Frappuccino||venti, 24 fl. oz.||140|
|Starbucks VIA House Blend Instant Coffee||1 packet, makes 8 fl. oz.||135|
|McDonald’s Coffee||large, 16 fl. oz.||133|
|Maxwell House International Café, all flavors||2⅔ Tbs., makes 12-16 fl. oz.||40-130|
|Seattle’s Best Coffee—Iced Latte or Iced Mocha, can||9.5 fl. oz.||90|
|Starbucks Frappuccino Coffee, bottle||9.5 fl. oz.||90|
|International Delight Iced Coffee||8 fl. oz.||76|
|Maxwell House Lite Ground Coffee||2 Tbs., makes 12 fl. oz.||50-70|
|Dunkin’ Donuts, Panera, or Starbucks Decaf Coffee||16 fl. oz.||15-25|
|Maxwell House Decaf Ground Coffee||2 Tbs., makes 12 fl. oz.||2-10|
|Starbucks Tazo Awake—Brewed Tea or Tea Latte||grande, 16 fl. oz.||135|
|Starbucks Tazo Earl Grey—Brewed Tea or Tea Latte||grande, 16 fl. oz.||115|
|Starbucks Tazo Chai Tea Latte||grande, 16 fl. oz.||95|
|Starbucks Tazo Green Tea Latte—Iced or regular||grande, 16 fl. oz.||80|
|Black tea, brewed for 3 minutes||8 fl. oz.||30-80|
|Snapple Lemon Tea||16 fl. oz.||62|
|Lipton Pure Leaf Iced Tea||18.5 fl. oz.||60|
|Green tea, brewed for 3 minutes||8 fl. oz.||35-60|
|Lipton 100% Natural Lemon Iced Tea, bottle||20 fl. oz.||35|
|Arizona Iced Tea, black, all varieties||16 fl. oz.||30|
|Nestea Unsweetened Iced Tea Mix||2 tsp., makes 8 fl. oz.||20-30|
|Arizona Iced Tea, green, all varieties||16 fl. oz.||15|
|Lipton Decaffeinated Tea—black or green, brewed||8 fl. oz.||5|
|Herbal Tea, brewed||8 fl. oz.||0|
|FDA official limit for cola and pepper soft drinks||12 oz.||71 (200 parts per million)|
|Pepsi MAX||12 oz.||69|
|Mountain Zevia (Zevia)||12 oz.||55|
|Mountain Dew, regular or diet||12 oz.||54 (20 oz. = 90)|
|Diet Coke||12 oz.||47 (20 oz. = 78)|
|Dr Pepper or Sunkist, regular or diet||12 oz.||41 (20 oz. = 68)|
|Pepsi||12 oz.||38 (20 oz. = 63)|
|Coca-Cola, Coke Zero, or Diet Pepsi||12 oz.||35 (20 oz. = 58)|
|Surge||8 oz.||35 mg (20 oz. = 87.5 mg)|
|Coca-Cola Life||12 oz.||27 mg (20 oz. = 45 mg )|
|Pepsi True||7.5 oz.||24 mg (20 oz. = 64 mg)|
|Barq’s Root Beer, regular||12 oz.||23 (20 oz. = 38)|
|7-Up, Fanta, Fresca, ginger ale, or Sprite||12 oz.||0|
|Root beer, most brands, or Barq’s Diet Root Beer||12 oz.||0|
|Bang Energy Drink||16 fl. oz.||357|
|Redline Energy Drink||8 fl. oz.||316|
|Rockstar Citrus Punched||16 fl. oz.||240|
|5-hour Energy||1.9 fl. oz.||208|
|Full Throttle||16 fl. oz.||200|
|Frava Caffeinated Juice||16 oz.||200 mg|
|Monster Energy||16 fl. oz.||160|
|Rockstar||16 fl. oz.||160|
|Venom Energy Drink (Dr Pepper/Seven Up Inc.)||16 fl. oz.||160|
|NOS Energy Drink (Coca-Cola)||16 fl. oz.||160|
|AMP Energy Boost Original (PepsiCo)||16 fl. oz.||142|
|NoDoz Energy Shots||1.89 fl. oz.||115|
|Mountain Dew Kick Start||16 fl. oz.||92|
|ávitāe Caffeinated Water||16.9 oz.||90 mg|
|Red Bull||8.4 fl. oz.||80|
|V8 V-Fusion+Energy||8 fl. oz.||80|
|Ocean Spray Cran-Energy||20 fl. oz.||55|
|Glacéau Vitaminwater Energy||20 fl. oz.||50|
|Starbucks Refreshers||12 fl. oz.||50|
Caffeinated Snack Foods
|Crackheads²||1 box, 40g||600|
|Crackheads Espresso Bean Candies, regular||1 package, 28 pieces||200|
|Wired Waffles||1 waffle||200|
|MiO Energy, all flavors||1 squirt, ½ tsp.||60|
|Crystal Light Energy||½ packet||60|
|Jelly Belly Extreme Sport Beans||1 package, 1 oz.||50|
|Jolt Gum||1 piece||45|
|Muscle Milk Orange Energy Chews||1.27 oz.||30 mg|
|Blue Diamond Almonds, Roasted Coffee Flavored||1 oz.||25|
|Perky Jerky||1 package, 1 oz.||10|
Ice Cream & Yogurt
|Bang!! Caffeinated Ice Cream||4 fl. oz.||125|
|Cold Stone Creamery Mocha Ice Cream||Gotta Have It, 12 fl. oz.||52|
|Starbucks Coffee Ice Cream||4 fl. oz.||45|
|TCBY Coffee Frozen Yogurt||large, 13.4 fl. oz.||42|
|Dannon All Natural Coffee Lowfat Yogurt||6 oz.||30|
|Häagen-Dazs Coffee Ice Cream||4 fl. oz.||29|
|Stonyfield Gotta Have Java Nonfat Frozen Yogurt||4 fl. oz.||28|
|Starbucks Mocha Frappuccino Ice Cream||4 fl. oz.||25|
|Baskin Robbins Jamoca Ice Cream||4 fl. oz.||20|
|Dreyer’s or Edy’s Grand Ice Cream—Coffee or Espresso Chip||4 fl. oz.||17|
|Breyers Coffee Ice Cream||4 fl. oz.||1|
|Häagen-Dazs Coffee Almond Crunch Snack Size Bar||1.8 oz.||10|
|Dreyer’s, Edy’s, or Häagen-Dazs Chocolate Ice Cream||4 fl. oz.||less than 1|
Chocolate Candy & Chocolate Drinks
|Awake Caffeinated Chocolate Bar||1.55 oz.||101|
|Awake Caffeinated Chocolate Bites||0.53 oz.||50|
|Starbucks Hot Chocolate||grande, 16 fl. oz.||25|
|Hershey’s Special Dark Chocolate Bar||1.5 oz.||20|
|Hershey’s—Milk Chocolate Bar||1.6 oz.||9|
|Hershey’s Kisses||9 pieces, 1.4 oz.||9|
|Hershey’s Cocoa||1 Tbs.||8|
|Dove Dark Chocolate Silky Smooth Promises||5 pieces, 1.4 oz.||4|
|Silk Chocolate Soymilk||8 fl. oz.||4|
|Hershey’s Chocolate Lowfat Milk, bottle||12 fl. oz.||2|
|Zantrex-3 weight-loss supplement||2 capsules||300|
|NoDoz or Vivarin||1 caplet||200|
|Excedrin Migraine||2 tablets||130|
|Midol Complete||2 caplets||120|
|Bayer Back & Body||2 caplets||65|
|Caffeine Powder||1/16 tsp. (200mg)||200 mg|
|Liquid Caffeine||½ tsp. (.08 oz.)||41.5|
November 2014. Most information was obtained from company Web sites or direct inquiries.
Serving sizes are based on commonly eaten portions, pharmaceutical instructions, or the amount of the leading-selling contaner size. For example, beverages sold in 16-ounce or 20-ounce bottles were counted as one serving.
Additional information: Juliano, L.M. & Griffiths, R.R. (2005). “Caffeine.” In Lowinson, J.H., Ruiz, P., Millman, R.B., Langrod, J.G. (Eds.). Substance Abuse: A Comprehensive Textbook, Fourth Edition. (pp 403-421). Baltimore: Lippincott, Williams, & Wilkins.