Print This Page SparkPeople

The Buzz on Caffeine

Health Benefits and Risks of Caffeine Consumption
  -- By Becky Hand, Licensed & Registered Dietitian
Caffeine: Most of us can't get through the day without it. Whether brewing a fresh pot of coffee in the morning, enjoying lunch with a refreshing can of cola, or recharging in the afternoon with an energy drink, we have many routines and food rituals revolving around this energizing substance. Found naturally in the leaves, seeds and fruits of more than 60 plants (including cocoa beans, kola nuts, guarana, yerba mate, green tea extract and tea leaves) and added to many other foods and beverages, caffeine is the world's most popular stimulant. In the US alone, more than 80% of adults consume it. 
 
Like many commonly enjoyed foods and ingredients, we get mixed information about caffeine. Sometimes we hear it does a body good. Other times, we hear it's bad for us. Keep reading to uncover the truth about caffeine: how it works—and how it affects your health.
 
Why Caffeine Keeps You Charged
The brain produces a natural sedative called adenosine, which binds to the appropriate receptor sites in the brain, resulting in a drowsy feeling. Adenosine levels rise during daytime/waking hours, encouraging sleep in the evening. While sleeping, adenosine levels drop, so you awaken refreshed and raring to go.  
 
Caffeine is similar in structure to adenosine. It temporarily binds to adenosine receptor sites in the brain.  This prevents adenosine from attaching itself to the sites and thus, wards off fatigue. If you regularly consume caffeine, you might also discover that you build up a tolerance because the brain makes more receptor sites as a result. Therefore, you need more caffeine to attach to these new sites and get the same results.

While caffeine is one of the most studied ingredients in food supply, there is still great confusion regarding its effects on health. For years caffeine has been included on the U.S. Food and Drug Administration's list of substances that are "generally recognized as safe" (GRAS) list. Extensive research has been conducted on numerous health aspects of caffeine consumption. Here is a synopsis of the findings regarding caffeine and health.
 
5 Health Benefits of Caffeine
4 Health Risks of Caffeine Consumption
6 Things Caffeine Has NO Affect On
How Much Caffeine Are You Consuming?
While a moderate caffeine intake up to 400 milligrams a day is considered safe for a healthy adult, it is not mandatory for the amount of caffeine to be listed on the label of foods, beverages or supplements.  Therefore, determining your daily intake can be difficult. The chart below shows estimated caffeine contents in commonly used foods, beverages and pills. The amount will vary based on ingredients used, brewing method, brewing time and a company's formula.

Other nutritional supplements, such as weight-loss supplements, vitamin-mineral supplements, and sport-enhancing supplements might also contain caffeine in varying amounts. To determine if a supplement contains caffeine, look for plant names that contain caffeine on the ingredient list such as guarana, yerba mate, kola nut and green tea extract. Since products and formulas change, contact the company to see if the exact caffeine amount is available.  

Product Caffeine (mg) 
Coffee:  
Brewed coffee, 8 oz 80-160
Instant coffee, 8 oz 50-90
Decaf coffee, 8 oz 3-8
   
Medication:  
Alertness medication, pill 100-200
Appetite suppressants, pill 100-200
Headache medication, pill 65
   
Tea:  
Brewed black tea, 8 oz 30-90
Yerba mate, 8 oz 85
Instant tea, 8 oz 25-50
Iced tea, 8 oz 10-50
Green tea, 8 oz 25
Herbal tea, 8 oz 0
   
Flavored Milks:  
Chocolate milk, 8 oz 2-7
Chocolate soy milk, 8 oz 4-5
   
Soft Drinks:  
Mountain Dew, 12 oz 54
Cola, 12 oz 35-50
Root beer, 12 oz 0-25
   
Energy Drinks:  
Energy shots, 1.9 oz 200
Energy drinks, 8 oz 80-100
Energy vitamin water, 20 oz 50
   
Sweets:  
Energy gum, per piece 35-100
Coffee ice cream, 4 oz 20-50
Dark chocolate, 1.5 oz 10-50
Milk chocolate, 1.5 oz 5-20
Hot chocolate, 8 oz 13
Chocolate flavored syrup, 1 oz   4-5
Chocolate ice cream, 4 oz Less than 1

Cutting Back on Caffeine:  If you decide it's time to cut back on your caffeine intake, there are two basic approaches you can try:
The Final Scoop 
In moderation, caffeine can increase alertness, performance, productivity and may have some health benefits. Too much, however, can ove-stimulate the nervous system and bring about restlessness, irritability, and insomnia. Based on current evidence, the U.S. Beverage Guidance Panel suggests that moderate caffeine intake up to 400 milligrams a day is safe for healthy adults and is not associated with increased risk of heart disease, hypertension, osteoporosis or high cholesterol. Discuss your daily caffeine intake plan with your doctor as it relates to your medical conditions and tolerance. 
 
Note:  This article was specifically researched and written regarding caffeine intake and the adult population. Refer to the American Academy of Pediatrics for information on caffeine intake for children and adolescents. 
 
Sources:
Aedma M, Timpmann S, Ööpik V. "Effect of Caffeine on Upper Body Anaerobic Performance in Wrestlers in Simulated Competition Day Conditions." Int J Sport Nutr Exerc Metab. 2013 May 22.
 
Center for Science in the Public Interest, "Caffeine Content of Food and Drugs," www.cspinet.org, accessed on October 21, 2013.
 
EnergyFiend, "Caffeine Amounts," www.energyfiend.com, accessed on October 21, 2013.
 
Eskelinen MH, Kivipelto M. "Caffeine as a protective factor in dementia and Alzheimer's disease." J Alzheimers Dis. 2010;20 Suppl 1:S167-74.
 
Hodgson AB, Randell RK, Jeukendrup AE. "The metabolic and performance effects of caffeine compared to coffee during endurance exercise." PLoS One. 2013;8(4).
 
Hursel R, Viechtbauer W, Westerterp-Plantenga MS. "The effects of green tea on weight loss and weight maintenance: a meta-analysis." Int J Obes (Lond). 2009 Sep;33(9):956-61.
  
Lieberman JA, Sylvester L, Paik S. "Excessive sleepiness and self-reported shift work disorder: An internet survey of shift workers." Postgrad Med. 2013 May;125(3):162-71.
 
March of Dimes, "Caffeine in Pregnancy," www.marchofdimes.com, accessed on October 21, 2013.
 
Nawrot P, Jordan S, Eastwood J, Rotstein J, Hugenholtz A, Feeley M.
"Effects of caffeine on human health." Food Addit Contam. 2003 Jan;20(1):1-30.
 
Palacios N, Gao X, McCullough ML, Schwarzschild MA, Shah R, Gapstur S, Ascherio A. "Caffeine and risk of Parkinson's disease in a large cohort of men and women." Mov Disord. 2012 Sep 1;27(10):1276-82.
 
Rosalie Marion Bliss, ARS. "Caffeine-Containing Botanicals in Dietary Supplements," Agricultural Research, April 2009.
 
Sengpiel V, Elind E, Bacelis J, Nilsson S, Grove J, Myhre R, Haugen M, Meltzer HM, Alexander J, Jacobsson B, Brantsaeter AL. "Maternal caffeine intake during pregnancy is associated with birth weight but not with gestational length: results from a large prospective observational cohort study." BMC Med. 2013 Feb 19;11:42.
 
Snel J, Lorist MM. "Effects of caffeine on sleep and cognition." Prog Brain Res. 2011;190:105-17.
 
The Nutrition Transition, "Tea, Coffee, Unsweetened," www.cpc.unc.edu/projects/nutrans, accessed on October 21, 2013.