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How much caffeine is too much caffeine?

Lets say you have a cup of coffee or tea or soda to wake up every morning. Do you ask yourself:

How much caffeine did you consume?

Is it OK to have that second cup?

Do you feel different before and after caffeine? Do you feel happier, calm or just more awake?

I started looking into caffeine consumption after my husband reported last week that he didn't feel a need a have a second cup of coffee on that Friday when he treated himself to a Starbucks 'Grande' 16 oz Coffee instead of a cup of regular coffee from his office machine.

This post is also dedicated to a couple of my students who get through their busy week with a ton of energy drinks, chocolate protein shakes and Starbucks coffee laden with espresso shots. I hope they reconsider their consumption after reading this post.

So, how much caffeine is too much caffeine?

The Mayo Clinic suggests: "Up to 400 milligrams (mg) of caffeine a day appears to be safe for most healthy adults. That's roughly the amount of caffeine in four cups of brewed coffee, 10 cans of cola or two "energy shot" drinks." The American College of Obstetricians and Gynecologists recommends that pregnant women restrict their caffeine intake to less than 200 mg/day.

OK - so for a healthy, non-pregnant adult, four cups of brewed coffee are totally fine. Yes?

No, wait a minute.

According to Washington DC-based Center for Science in the Public Interest (CSPI), caffeine content levels vary a lot across different beverages and brands. In other words, not all coffees are equal - The caffeine in Starbucks Coffee is different from that of Dunkin, Blue Bottle, Folgers or Maxwell.

Regulatory agency, Food and Drug Administration (FDA) states that the amount in brewed beverages can vary depending on such factors as how and where the coffee beans and tea leaves were grown and processed and how the beverage product is prepared, type of coffee bean, roast style, and the serving size.

As stated by CSPI, a 20 oz serving size of Dunkin Donuts coffee Espresso Shot is about 400 mg of caffeine, a 16 oz cup of Starbucks Coffee Blonde Roast, 360 mg.

No wonder, my husband did not need another cup of coffee! His recommended daily caffeine intake was already fulfilled by that one cup of grande Starbucks coffee.

In contrast, tea drinkers can relax a little. A 16 oz cup of brewed green or black tea is about 80 mg. And by the way, decaf drinks typically has caffeine too....just much less of it.

Like coffee and tea, sodas and energy drink brands also have different levels of caffeine. A 10-oz serving of Pepsi Zero Sugar is 75 mg and a Diet Coke of the same size is 23 mg. A potent 2-oz drink like 5-hour Energy has 200 mg of caffeine and smaller Red Bull cans have about 80 mg.

Most caffeinated nutritional / fitness shakes such as Ensure's Mocha or Kellogg's Cappuccino , Vitaminwater Energy Tropical Citrus, Odwalla Chai have high levels of caffeine. Even energy snacks from Clif Shot, Awake and Gu are pretty caffeinated.

Several of the coffee icecreams, coffee yogurts, chocolates and chocolate drinks probably have about the same levels of caffeine as a cup of tea.

Some of us are more sensitive to caffeine than others. If you get migraines or headaches, an upset stomach, fast heart beats, muscle tremors, jitters or insomnia, you may want to reduce your caffeine consumption.

Between chocolate, soda and chocolate milk, our kids (ages 2-19) are consuming much more caffeine, compared about 40-50 years ago, albeit in lower doses. As they grow, they will consume coffee and tea in addition to the chocolate and soda. We must strive to know more about caffeine and the effects it has on our bodies.

Remember that caffeine is soluble in water and lipids, easily crosses the blood–brain barrier, and can be found in all body fluids. While it increases alertness and wakefulness, acute consumption can stimulate an increase in blood pressure and increase your heart rate. So, while ingested caffeine at recommended doses is safe, excess caffeine consumption is increasingly being recognized as potentially harmful.

Alcohol-mixed energy drinks are just a bad idea. Products that tout pure or highly concentrated caffeine in powder or liquid forms are probably just detrimental to our health and should be just avoided.


About the Center for Science in the Public Interest (CSPI)

Founded in 1971, the Center for Science in the Public Interest is perhaps the oldest independent, science-based consumer advocacy organization with an impressive record of accomplishments and a clear and ambitious agenda for improving the food system to support healthy eating. CSPI provides practical advice to consumers interested in nutrition, food safety, and health. Talk show host Oprah Winfrey called Nutrition Action Health letter "the master-mind critic that sounded the food alarms." Sign up for their free health tips.

About Food & Drug Administration (FDA)

The Food and Drug Administration is responsible for protecting the public health by ensuring the safety, efficacy, and security of human and veterinary drugs, biological products, and medical devices; and by ensuring the safety of our nation's food supply, cosmetics, and products that emit radiation.

About Mayo Clinic

Mayo Clinic is a nonprofit organization committed to clinical practice, education and research, providing expert, whole-person care to everyone who needs healing.


About Me


Hey there! I am Komal Kapoor,

LA-based Indian-American who loves to share experiences in food, world travel, wellness and luxury!


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