Caffeine has become synonymous with energy, and about 90 percent of adults around the globe consume it daily in one form or another. But the stimulant is showing up in some pretty unusual places, including energy bars, jelly beans, mints and peanut butter.

Consumer Reports outlines some key health-related facts about this ubiquitous compound:

Caffeine in moderation is okay for most people, but overdoing it can be dangerous.

According to the Agriculture Department’s latest Dietary Guidelines for Americans, up to 400 milligrams of caffeine per day — the amount in two to four eight-ounce cups of coffee — can be part of a healthy diet for adults. The Food and Drug Administration says 600 mg per day is too much.

“It varies from individual to individual, but consuming more than your normal amount of caffeine could make you feel nervous, anxious, irritable or jittery, and may cause excessive urine production or irregular heartbeat,” says caffeine researcher Maggie Sweeney, a postdoctoral research fellow at the behavioral pharmacology research unit at Johns Hopkins University School of Medicine. “And for those who have anxiety or insomnia, it could worsen their symptoms.”

Caffeine intake can easily add up if you drink coffee and also consume several caffeinated products in a day. For example, have a Starbucks coffee in the morning, a water with added caffeine in the afternoon and a few caffeinated mints during the day, and you could easily exceed 600 mg. At extremely high doses, caffeine can lead to coma, convulsions, heart attack, vomiting and even death.

Where you get it from matters.

Caffeine is naturally present in the seeds, leaves and fruit of many plants, including cacao, coffee and tea. Packaged foods containing ingredients such as coffee and green tea extracts, guarana, kola nut and yerba mate will add to your daily dose. But synthetic versions of the stimulant may also be infused into food and drink.

And although there’s no chemical difference between natural and synthetic caffeine, Sweeney says, the other ingredients in the product may interact with the caffeine. For example, the sugars or the amino acid taurine in many caffeinated energy drinks produce different effects on mood and attention than caffeine alone.

We still don’t know everything about caffeine.

Caffeine is speedily and completely absorbed through the intestines, so you can get that eye-opening pop in as little as 10 minutes. Once in the brain, it targets and blocks a cascade of neurotransmitter signals that would normally make you sleepy. But it can also have other effects on your body, both positive and negative. More research is needed, but studies have indicated that caffeine could both precipitate and alleviate headache, boost athletic performance and memory, protect against Type 2 diabetes, prevent constipation and exacerbate menopausal hot flashes.

You shouldn’t get all of your caffeine in a single shot.

Pairing a cup of java with caffeinated versions of yogurt and peanut butter at breakfast may sound like a boon, but it may be too much caffeine to handle at once. There’s a difference between getting 400 mg of caffeine over the course of a day and consuming that amount or more in one sitting, notes Neal Benowitz, a professor of medicine at the University of California at San Francisco. “With drugs that affect mood or behavior such as caffeine, the faster the rise in the drug level in the body, the more intense the response,” Benowitz says.

It’s not always easy to find out how much caffeine a product contains.

The FDA requires food manufacturers to note on the label that a product has added caffeine, but they are not obligated to state the amount. And if a product is made with a substance that naturally contains caffeine, such as guarana or cocoa, that source will be named in the ingredients list, but no mention of caffeine is required.

The FDA has explicitly approved added caffeine in just one product, colas, but manufacturers have added it to other foods and beverages. The agency is concerned about the increase in caffeinated products, especially those marketed to kids, and is investigating the potential health consequences of consuming too much.

Copyright 2016. Consumers Union of United States Inc.

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