How many servings of a beverage does it take to give you a lethal dose of caffeine?

 

I enjoy looking for articles at the McGill Office for Science and Society. There is one on August 26, 2022 by intern Cat Wang titled How many Yerbas does it take to overdose on caffeine? She says:

 

“Let’s crunch the numbers - how much is too much? A lethal amount of caffeine is about 180 mg/L, which has been determined by examining the blood of patients who died from overdose. When you consume ~100 mg of caffeine, it raises your blood caffeine levels by about 5 mg/L, meaning it’ll take almost 40 cups of coffee to be lethal. It’s also important to consider that caffeine takes as little as 15 minutes to take effect and has an average half-life of five hours. Half-life is a measure of how quickly your body eliminates a certain substance; if you have your typical 200 mg, then wait five hours, you will still have 100 mg left in your system. Because your body is constantly metabolizing, you would also need to get those coffees down within a few hours for it to kill you. Weight, other medical conditions, and genetics also play a role when it comes down to how caffeine reacts in your system, so lethal dose can vary greatly from person to person. To keep things simple, most scientists define the lethal dose to be 10 grams. Let’s use that for our calculations.”

 

 

 

 

 

 

 

 

 

 

Kat has an excellent vertical bar chart titled Number of servings of various beverages it takes to reach a lethal dose of caffeine. (It had results for items sold in the cafeteria at that university in Montreal). My horizontal bar chart version is shown above. I have left off the Rise Kombucha she had, and added the truck-stop favorite 5 Hour Energy Extra Strength Shot. You would have to drink an unlikely 67 ~pint cans of Yerba Mate or 300 12-ounce cans of Coca Cola to get a lethal dose.

 

 

 

 

 

 

 

 

 

 

If we multiply the number of servings by the ounces in a serving, we get the liquid volumes shown above, which are more conveniently shown in gallons (at 128 ounces per gallon). Those 67 cans of Yerba Mate amount to 8.1 gallons, and 300 12-ounce cans of Coca Cola to 28.1 gallons. But 43.5 1.93 oz. bottles of the very concentrated 5 Hour Energy Extra Strength Shots (230 mg caffeine) only totals to 2/3 of a gallon. A doomsday prepper might have that many bottles stockpiled, so an uninformed teenager could accidentally take a lethal overdose.  

 

Another article from the U. S. Food & Drug Administration is titled Spilling the beans: How much caffeine is too much? It says:

 

“For healthy adults, the FDA has cited 400 milligrams a day – that’s about for or five cups of coffee – as an amount not generally associated with dangerous, negative effects.

 

….The FDA estimates toxic effects, like seizures, can be observed with rapid consumption of around 1,200 milligrams of caffeine, or 0.15 tablespoons of pure caffeine.”

 

On April 19, 2022 I blogged about another article from McGill in a post titled How to do a better job of researching medical and health articles.