caffeine effect | Caffeine and You

Caffeine Lasts Longer Than Cocaine

May 14, 2013 By Kate Heyhoe

Caffeine’s half-life is three times cocaine’s. How long caffeine lasts also depends on your genes.

In the classic movie The Big Chill, actress Glenn Close snorts cocaine, which she hasn’t done in years. In the next scene, we see her sitting up in bed, wide-eyed, rambling, fidgety, and fully awake, while her husband sleeps soundly next to her. The next morning, he’s peppy and ready for a run, while she’s a wrung out rag of exhaustion.

Caffeine’s Complicated Half-Life

For many people, caffeine keeps them awake as effectively as cocaine, especially when consumed late in the day. It takes hours for both drugs to wear off.

How long a drug stays in the body is measured by its half-life – the amount time it takes for half the substance to be eliminated from the system.

Cocaine’s half-life is short, about 90 minutes. Caffeine’s is about three times longer – from five to seven hours – but caffeine is a far less potent psychoactive drug. In either case, after the half-life moment is reached, the substance continues to churn in your system with diminishing impact, until completely eliminated. And whether you’re a slow or fast metabolizer of caffeine is determined by your genes.

One gene in particular regulates caffeine, and goes by the formal name of CYP1A2. This gene comes in two versions (or alleles; in this case differentiated by a single nucleotide). It’s like having a switch that is either turned on or off. And this tiny variation (switched on or off) makes you either a slow or fast metabolizer of caffeine: it regulates how efficiently your liver breaks down and flushes caffeine from your system.

Genetics play a role, but other factors also affect how quickly the liver breaks down and eliminates caffeine, and this varies from person to person. For instance, smokers burn through caffeine quickly (ever notice smokers drink lots of coffee?). Caffeine’s half-life is 9-11 hours in pregnant women and 5-10 hours in women taking birth control pills. Liver function and certain medications also impact caffeine’s half life, as does age. Caffeine’s half-life can last as long as 30 hours in newborns.

Discover more about the complex world of caffeine in Caffeine Basics.

Taking Risks: Energy Drinks and Alcohol

January 3, 2013 By Kate Heyhoe

Got a thirst? Need a boost? Slurp down a can, or two – or more – of a refreshing, cold energy drink. Within minutes, moderate to high amounts of caffeine are churning through your brain and body. A moderate dose can be safe, even desirable. Too much caffeine, though, and you get the shakes, hands tremble, heartbeat races, and caffeine intoxication takes over. Like alcohol, the effects are intense, and they diminish over time.

This 16-ounce can of Xenergy contains 208 mg caffeine, considered very high; a same size Coke has 45 mg

Then there’s the problem of mixing caffeine with alcohol. Energy drinks and alcohol together are double-trouble. Caffeine does not reduce the effects of alcohol. You may feel more alert, but you’re just as impaired by the alcohol.

Studies have found that the combination of energy drinks and alcohol is more dangerous than drinking alcohol alone; caffeine’s stimulating buzz makes people less aware of being drunk. They perceive themselves as more in control than they really are; they’re likely to drink more alcohol, or feel confident about driving safely, for instance.

The effects go beyond mental perception; the physical risks are real, too. Caffeine is a stimulant. Alcohol is a depressant. Together they send mixed messages to the nervous system and the heart. The combination is especially risky for people with heart rhythm problems.

Teen deaths have been attributed to minor or undiagnosed cardiac problems and high caffeine, delivered in extreme doses by energy drinks. High levels of caffeine can boost heart rate and blood pressure in some people, causing palpitations. Some teens weren’t yet aware they had cardiac conditions, which under normal circumstances had never proved problematic.

Energy Drink Regulations Teeter on Teen Safety

Energy drinks make high caffeine consumption easy, especially in young people.

When energy drinks were linked to teenage deaths, the FDA became pressured to increase regulation and even ban energy drinks altogether. Some, including U.S. Senator Dick Durbin, say energy drinks use FDA loopholes to circumvent rules about caffeine content.

Motivated by the prospect of increased regulation, companies have slightly modified how they market energy drinks and soft drinks, especially to teens – a few have even altered their caffeine content and reclassified their products with the FDA as soft drinks, rather than dietary supplements. Chapter 5 outlines how energy drink and soft drink makers are choosing to list caffeine, including new marketing strategies by the ABA (American Beverage Association).

Conclusion

Energy drinks are as sweet, cold and bubbly as soda pop. They go down fast and easy. Some come in large containers, double or triple the size of a standard cup of coffee. Anyone could slurp up several cans in a day, especially thirsty athletes. But there’s a difference: energy drinks are often many times more caffeinated than sodas. Energy drinks can range from 50 to 500 mg of caffeine per container – while a 12-ounce can of Coke contains 34 mg of caffeine.

Energy shots aren’t bubbly. Most don’t even taste good. But since a 2-ounce shot amounts to just 1/4 cup, you can slam down 50 to 200 mg of caffeine in one or two quick gulps.

And this is where most criticism lies: With energy drinks and shots, it’s easy to quickly consume too much caffeine – especially unintentionally. Most people don’t realize that caffeine is biphasic: it’s safe in low to moderate doses, but can be risky in high doses. Soft drinks have a legal limit to the caffeine they may contain, and most are about as potent as brewed tea. Energy drinks and shots have no such limit. And just finding the amount of caffeine a product contains requires keen eyesight to read tiny print on labels, or in some cases, some online research.

Both soft drinks and energy drinks reflect flavors, packaging, and marketing designed to appeal to teenagers and children. But young people have brains and bodies that are still developing and don’t handle the drug’s effects in the same way as adults. From chocolates to coffee, and sodas to energy drinks, caffeine’s an everyday part of society. But no one wins when caffeine is taken in unsafe amounts. Chapter 11 dives deeper into the effects of caffeine in young people, as well as newborns and pregnant women.

In the next chapter: Store shelves buzz with new caffeinated products, from MIO to maple syrup, keeping everyone from Israeli pilots to average drivers alert.

Caffeine Basics: Table of Contents

6. Making Caffeine Work for You

January 6, 2013 By Kate Heyhoe

Be the caffeine-consumer you want to be. The next six chapters explore caffeine’s effects – so you can decide just what sort of relationship you want to have with caffeine.

Should caffeine be a take-it-or-leave-it acquaintance? A team player? A friend with benefits? A marriage partner to wake up with every morning? Or is your relationship with caffeine doomed, a heart-breaker that will never work? Perhaps you keep caffeine’s number on emergency speed dial, like the AAA tow truck that only shows up when your car breaks down.

Outdated research studies have clouded people’s understanding of how caffeine works, so these chapters focus on clearing up myths and misconceptions. Caffeine can be a great friend, or for some, it can be a foe. But for most of us, caffeine offers safe and attractive features, when taken in low to moderate doses.

Much Depends on You

The intensity of caffeine’s effects largely depends on you: your chemistry, your age, your sex, how your brain is wired, and your genes – which help determine if you’re a slow or fast metabolizer.

Why do people respond so differently to caffeine? Or conversely, why do people respond so similarly? Given that 90 percent of the world now consumes caffeine every day, this chapter poses the questions: Why is caffeine so important to humans? Is it good or bad for us?

Chapter 7, which follows this chapter, covers caffeine’s half-life, the length of time caffeine stays in a person’s system, and its biphasic nature, meaning low and high doses produce drastically different effects (more is not better). So if you want you want to skip ahead and then return to this part, that’s fine. The information in both chapters goes hand-in-hand.

Coming up: Is caffeine an evolutionary tool in the human toolbox?

Caffeine Basics: Table of Contents

Caffeine in the Toolbox

January 6, 2013 By Kate Heyhoe

Is caffeine a tool for modern humans?

Imagine you’re at the beach. You slide on your sunglasses and spread a towel out on the sand. The sun beats down. Your skin feels hot, so you apply sunscreen. At first you enjoy the sun but as the afternoon wears on, you flee, back to the car and eventually home to an air-conditioned house. As you change clothes, you admire your tan.

You’ve just demonstrated the remarkable human ability to adapt, both biologically and by inventing things that change our surrounding conditions.

Human adaptation is key to our success. Our skin releases melanin to protect against the sun’s rays. We build shelters to keep out wind, rain, and varmints. Our machines change the temperature of the air. Our ability to cope with the variability of our environment is our biggest advantage. And somehow these things, these adaptations, just flow together over time: we’re not always aware of how we come to cope. We just do.

Is Caffeine an Adaptational Tool?

In so many ways, caffeine makes humans more adaptable. With caffeine, we can avoid sleep. Day can be night, and night can be day. We can ward off hunger and fatigue. We’re more social and exchange ideas. We solve problems, and make things all day long. And when we feel pain, caffeine stops the hurt and keeps us going.

Why do we include caffeine in our diet? It doesn’t provide calories, fat, or protein. It does stimulate neurochemicals that change how we interact with our environment. It’s a source of antioxidants, and it’s delivered in natural substances that contain even more antioxidants. Perhaps we choose caffeine because in some ways, it helps us more than it harms us.

Caffeine’s effects may be making more of a long-term impact than we can easily see. But the fact that most people experience caffeine on a regular, daily basis suggests we may be operating differently, in some big-picture way, from times when caffeine was not widely consumed.

Caffeine can be a powerful tool in the human toolbox. But it comes without a manual. We’re still learning how it works. Fortunately, new tools like MRI scanners and human genome mapping are helping us figure it out. But many of caffeine’s mechanisms – the nuts and bolts of how it works – remain unclear.

Caffeine’s Effects: Good or Bad?

If you’re tempted to lump caffeine into mutually exclusive “good” or “bad” categories, don’t. Caffeine won’t fit. Current research finds evidence that caffeine has benefits, is safe in low to moderate doses, yet it can also be risky for some people. The FDA puts almost no restrictions on its use, but the medical community is more cautious when children, teens, pregnant women, and people with compromising health conditions are involved.

Despite years of research, caffeine remains somewhat mysterious, yet promising.

Caffeine is a drug, but largely an unregulated one. It can be a safe way to increase alertness, reduce fatigue, elevate mood, and improve sports performance. As delivery vehicles, coffee, tea chocolate and other botanicals contain beneficial antioxidants, and may prevent some cancers. Caffeine may also prevent some cancers, lower the risk of diabetes and Parkinson’s disease, and reduce the effects of cognitive aging.

Caffeine probably won’t make you smarter. But it does appear to boost our brains in happy, productive ways. A large number of studies indicate caffeine can help you work faster, increase focus, aid concentration, reduce attention lapses, and benefit recall. How and when you choose to use caffeine may give you an edge.

How much caffeine gives you the best boost? Click to the…next section

Caffeine Basics: Table of Contents

Low or High Doses: Caffeine’s Biphasic Buzz

January 6, 2013 By Kate Heyhoe

Caffeine is safe in low doses, but high doses are risky

Caffeine is biphasic – meaning it delivers significantly different effects when taken at low doses than at high ones.

We see this in research studies, when subjects are given small or large amounts of caffeine. But you and I can also feel the difference.

The more caffeine you ingest doesn’t mean the better the buzz. In fact, caffeine’s most popular effects – feeling good, awake, and alert – happen at low to moderate doses (100-300 mg, or one to three cups of coffee, depending on the person).

At higher doses, caffeine intoxication sets in: jitters, heart palpitations, anxiety, nausea, increased blood pressure, and such. Feeling good turns to feeling bad.

When products deliver high amounts of caffeine in concentrated doses, it’s easy to ingest too much in a short period. People with heart conditions and young people are especially vulnerable to caffeine’s adverse effects. Some energy drinks, energy shots, caffeine powder, and certain “dietary supplements” are more likely to deliver risky doses of caffeine.

Being Smart About Research Results

More and more, caffeine seems to be good for us in many ways. It’s a promising but still mysterious substance. Research results tend to conclude with the admonition “More research is clearly needed.” Or, “The mechanisms of action that account for these effects are uncertain at this time.”

Research may suggest a correlation between caffeine and an end result, but we aren’t always sure what caffeine does to get to that result.

Correlation doesn’t automatically mean causality either; there may be other factors at play, such as other ingredients in the beverage (like antioxidants), or the genetic types of the subjects. Journalists, and researchers, constantly conflate coffee with caffeine, so it’s often hard to tell which substance is really the active player.

Many of caffeine’s adverse effects reported prior to the 21st century seem to have been disproved, or not substantiated. Faulty methodology, unknowns like the influence of genetics, small sample studies, cigarette smoking, and other factors have pretty much tossed most of the scary warnings about caffeine out the door. Some prudent warnings do remain because we just don’t know enough, like the effects on newborns.

In some studies, the amount of caffeine makes a difference in results; one cup of coffee or 100 mg may be as beneficial as drinking water (i.e., no special therapeutic effect), while others require a hefty four to six cups of coffee or the caffeinated equivalent, which is enough to throttle many drinkers into the jitter zone. To make things even more confusing, caffeine in coffee may not yield the same results as caffeine in tea, sodas or energy drinks, or these other beverages may not have been tested as rigorously as coffee.

Finally, potential conflicts of interest can influence the results or their interpretation. Trade associations for coffee, sodas and energy drinks, tea, and chocolate actively fund scientific research studies. They may have no influence on the results, but it’s good to know who’s paying the bills, especially when results are conflicting or suddenly groundbreaking.

Next up: It’s all about you! How your uniqueness determines caffeine’s effects…Head over to Chapter 7

Caffeine Basics: Table of Contents