How much caffeine is safe?

What is caffeine?

Caffeine is a naturally occurring chemical found in a wide variety of plant sources, such as coffee beans, tea leaves, kola nuts, and cacao (chocolate) beans. It can also be man-made. Caffeine has a long history of use as a mild stimulant, and about 85% of Americans consume caffeine daily. It has now found its way into a wide variety of products, most notably over-the-counter alertness products and energy drinks, but also many food products. The Center for Science in the Public Interest maintains an updated list of common caffeine sources.

How caffeine affects the body

The effects of caffeine on adults are well known. Positive effects include increased alertness, physical performance, and focus. Negative effects include jitteriness, stomach upset, high blood pressure, trouble sleeping, increased urine production, and possible interactions with other medications and supplements.

How much caffeine is too much?

For most adults, the FDA recommends limiting daily caffeine consumption to about 400 mg (2–3 12 oz cups of coffee). There is wide variation in how sensitive people are to the effects of caffeine and how rapidly they eliminate it from the body. The symptoms of mild caffeine overdose include shaky hands, a pounding heart, and a queasy stomach to start. Too many energy drinks consumed over a short time can put you in the emergency room with vomiting, palpitations, and high blood pressure. A severe overdose of caffeine can mean seizures and even death.

Can you overdose on caffeine?

Acute overdoses of caffeine are likely to cause nausea, vomiting, irritability, headache, fast heart rate, and (initially) high blood pressure followed by low blood pressure. Altered mental states are common with acute overdose, and hallucinations and seizures can occur. Fortunately, caffeine is rapidly cleared from the body. Death from acute caffeine overdose is rare.

Is caffeine safe for children?

While caffeine has been used to stimulate breathing in premature infants, medical experts generally agree that children less than 2 years of age should not be exposed to it. Older children exposed to caffeine are more likely to show decreased sleep time and, in some studies, increased symptoms of depression. Limiting caffeine intake until the teenage years is a good idea.

Is caffeine addictive?

Two hallmarks of addiction are craving for the substance and a withdrawal syndrome when the substance is taken away. Some people’s claim that they “cannot function without their coffee” is a form of craving. When people chronically exposed to high doses of caffeine stop taking it, a withdrawal syndrome can develop. Caffeine withdrawal symptoms can include headache, drowsiness, runny nose, irritability, and reduced work productivity. The withdrawal syndrome typically starts 12–24 hours after the last dose of caffeine and can last for up to 1 week.

Is caffeine safe during pregnancy?

For many years, it was assumed that daily doses of caffeine of 300 mg or less were safe in pregnancy. Some national and international health agencies considered daily doses of up to 200 mg to be safe in pregnancy. More recent evidence is beginning to paint a different picture, with daily doses as low as 100–200 mg being associated with increased risk of miscarriage, stillbirth, and low birth weight as well as some developmental impairments in the child. Because of its widespread presence in foods and drinks, it is almost impossible to avoid all caffeine consumption, but pregnant women should not consume obvious sources of caffeine like coffee, tea, caffeinated soft drinks, and energy drinks.

Is guarana a source of caffeine?

Guarana (Paullinia cupana) is a vine that grows in the Amazon and is a potent source of caffeine, as well as a minor source of other xanthine type stimulants (such as theophylline and theobromin. It is sometimes added to energy drinks, teas, and herbal preparations. The caffeine content from the guarana may not be clearly labeled. Guarana seeds contain about 2-4 times more caffeine than you would find in coffee beans. Because of the high concentration of caffeine present, and because products containing guarana are also commonly formulated with other sources of caffeine, it is important to moderate intake of these products. Ingesting too much guarana can cause similar effects as excessive coffee intake.

What should I do if someone has too much caffeine?

If you think someone has consumed too much caffeine, use the webPOISONCONTROL^® online tool to get help, or call your poison center at 1-800-222-1222. Sometimes, it will be OK to watch at home with expert guidance, but sometimes the jitters can lead to seizures, so it's best to let the poison specialists figure it out.