Know how much you’re consuming and the levels that are considered safe

Caffeine…it’s everywhere, and many people don’t give it much thought other than craving their morning cup of coffee. A latte, energy drink or can of soda can taste delicious, improve mood and help increase alertness, making them an enjoyable daily ritual for many people. It’s estimated that between 80 and 90 percent of adults and children in North America habitually consume caffeine, and for most of us this isn’t a problem. However, for some, and especially at higher rates of consumption, there can be negative effects.

“We don’t usually think of it this way, but caffeine is a psychoactive drug —  it’s mood-altering, it acts on the brain, users can build a tolerance and its use is accompanied by a withdrawal syndrome that can be severe enough to affect day-to-day life.,” says Mary M. Sweeney, Ph.D., a caffeine researcher and faculty at Johns Hopkins University School of Medicine.

Caffeine is a central nervous system stimulant, and excessive intake may result in caffeine intoxication, a condition that can cause restlessness, agitation, severe insomnia, rambling thought and speech, gastrointestinal symptoms and even irregular heartbeat. In rare cases it’s severe enough to result in a medical emergency, Sweeney says.

More common, though, are less severe effects like nervousness, shakiness or sleep disruption.

There is no one-size-fits-all guideline for how much caffeine is too much. How fast the body metabolizes caffeine varies from person to person, and can be affected by both genetic and environmental influences, such as body weight, age, medications taken, tolerance and cigarette smoking.

Some medical conditions require caution when consuming any caffeine, and it is recommended that children 12 and under consume it sparingly if at all.

If caffeine use is causing problems like sleeplessness or anxiety, tapering consumption can help. “When people try to stop or cut back too quickly, they can get headaches or other symptoms — and caffeine cures those symptoms, so they often go right back to it even if that’s not what they wanted to do,” Sweeney says. Her program has found that cutting back by a percentage each week has helped people who had previously been unsuccessful in reducing consumption. For example, someone looking to cut back who has four cups of coffee per day may try drinking three cups a day for a week, then two cups per day for a week, etc., until they reach their caffeine goal.

The effects of caffeine withdrawal are also highly variable. Some people may not even notice it, while others have symptoms so severe that withdrawal interferes with regular functioning. In general, symptoms last between two and seven days, but for some, headaches can last up to three weeks. The more caffeine a person consumes daily, the longer and more severe withdrawal symptoms tend to be.

“Caffeine in moderation is not generally associated with negative consequences for most people,” says Sweeney. “We just want them to be aware and informed about the caffeine in their diet and the amount of caffeine that can be consumed safely for them.”                                                        



The following are some general guidelines for safe daily amounts:


Up to a maximum of 400 mg – Generally considered safe for adults with no other health issues

300 mg – Top limit recommended for women of childbearing age

200 mg – Top limit for pregnant or nursing women

100 mg – Although well under the “generally safe” threshold, even this low amount can trigger withdrawal symptoms in some people when discontinued