Why We Love Caffeine

January 1, 2013 By Kate Heyhoe

People Love Caffeine, But Why?

Japanese pachinko machines work like regular pinball machines, except instead of playing one large steel ball at a time, they shoot off dozens of smaller balls, clattering loudly through the playing field, bouncing, racing and ricocheting into obstacles, bumpers and rabbit holes. Lights flash, whistles blow, bells ding, all the while the balls are in play. Until they gradually exit the playing space and everything stops. Kind of like your body on caffeine.

Caffeine churns through your entire system like steel balls in a pachinko machine, lighting up different responses throughout your body. Part of this has to do with the fact that adenosine doesn’t reside only in your brain. (Adenosine is the neurotransmitter responsible for energy, among other things.) Your body is full of adenosine and adenosine receptors. Caffeine has the same ability to block those receptors wherever it finds them, which can lead to some pretty interesting effects in organs other than the brain.

Adenosine, though, is only one link in the chain. Caffeine creates a domino effect among neurotransmitters, making us love it all the more.

Just as some players keep the pachinko balls in play longer than others, caffeine bounces around in some people longer than others. And as we’ll see in the coming pages, the human genome is like the Wizard of Oz: it’s the chief programmer behind long- and short-term caffeine highs.

The Caffeine Rush

When caffeine blocks adenosine reabsorption, it puts a chain reaction of neurotransmitters into effect. The caffeine-adenosine synergy amps up the levels of dopamine, norepinephrine, acetylcholine, epinephrine, serotonin, and glutamate. And collectively, these substances are responsible for how you feel, act, and think on caffeine.

For instance, caffeine sparks an adrenaline rush. When caffeine stirs up the brain’s neural activity, the pituitary gland gets confused and thinks there’s an emergency. It dispatches hormones to the adrenal glands, telling them, “Yikes, guys! Create more adrenaline!” (also known as epinephrine).

What happens when adrenaline fires off?

Pupils dilate
The heart beats faster
Breathing tubes open up
Blood flow to the skin increases
Blood flow to the stomach slows
The liver releases sugar for extra energy
Blood pressure rises

It’s almost like falling in love. In fact, the caffeine rush is a lot like falling in love. In both cases, adrenaline and dopamine elevate our moods and our heartbeats, though it takes a few other neurotransmitters to spark true love. (Still, if you meet someone over coffee or a chocolate dessert, you may want to re-evaluate your relationship after the caffeine rush subsides.)

Warning: Caffeine Is Not for Everyone

Caffeine can cause bad reactions in some people, often at doses higher than 300 mg. Symptoms include restlessness, a loss of fine motor control, headaches, dizziness, insomnia, nausea, agitation, tremors, palpitations, and rapid breathing. Hand tremors, high blood pressure and anxiety are other common reactions. As we’ll see later, overuse of caffeine can also lead to serious abnormal behavior in some people, and caffeine withdrawal sparks a series of unfriendly experiences in the habitual user. Caffeine overdoses do happen, but deaths from caffeinated beverages are rare, and more likely in people with certain health conditions. Women and caffeine have a particularly roller-coaster relationship, affected by their cycle, aging hormones, pregnancy, and birth control pills. Infants and unborn children can retain caffeine in their systems for days. (More on this later.)

Caffeine is Addictive, in its own special way

Caffeine can have drawbacks, especially when mixed with alcohol and when taken in unsafe doses. It can be habit-forming, and is considered mildly addictive. It doesn’t create substance addiction the way other stimulants like nicotine and heroine do, but there’s a reason why people need their morning jolt of coffee or tea. Most people can overcome withdrawal effects of their habit, but people whose brains are already prone to addiction can face severe clinical-addiction symptoms while kicking their caffeine habit.

Bottom Line: Moderation is Okay!

The good news is most everyone agrees that caffeine in moderate consumption is safe for most people (a big change from the attitudes of the 1980s, when dubious research linked caffeine to all sorts of health problems). Since almost every person in the world consumes caffeine, this is very good news indeed. We’re not drinking ourselves into mass extinction (though some species on earth surely wish we were). And we may even be extending our lives and living healthier because of caffeine. But caffeine isn’t fully understood, and for some people, it can still be risky.

Fickle, Flighty and Evasive: Caffeine and Research Results

One thing I can say with certainty: Caffeine is quirky – fickle enough to confound its researchers. Perhaps this is just an indication of how little we know, errors in methodology, and contaminated research results. On the other hand, caffeine research results may be inconsistent because the substance itself is far more complicated than we’ve been able to pin down. Epigenetics, botany, and sociobiology are just some of the sciences pursuing the depth of caffeine’s mysteries.

One of the most difficult things about summarizing caffeine’s effects is that, depending on the circumstances, it can cause opposite responses. Scientists now believe the differences in research results may be due to genetics: some people are genetically more sensitive to caffeine than others. Studies that take these genetic differences into consideration (mostly conducted after 2010) may prove more reliable than previous ones.

Another hiccup in research results: regular vs. non-regular users. People who consume caffeine on a regular basis build up a tolerance to it, and their reactions, even when caffeine is not actively in their system, may be markedly different from people who never consume caffeine. If a study testing the effects of caffeine doesn’t control for this, the results may be inaccurate or not replicable. Even though caffeine has been tested on humans for decades, the results of early studies may lead to different conclusions when re-examined.

So don’t be surprised if you hear a wide range of claims about caffeine’s effects. Results that are consistent and replicable tend to be the most reliable. As a species, we are remarkable in our ability to question our own physiology. Even if we’re not always right at first, we keep trying, and changing our course or conclusions are an essential part of the ongoing scientific process. It took hundreds of years, and meticulous observations, for the earth to go from flat to round. With caffeine research, the next dozen years may be just as illuminating.

Coming Up…

This section on How Caffeine Works highlights only the top caffeine effects. Research is hot on the trail of more complicated results, from living longer to living healthier, as we’ll see later…

Caffeine Basics: Table of Contents

Your Habit: Set Point, Tolerance, Withdrawal

January 7, 2013 By Kate Heyhoe

When is caffeine too much of a good thing? The body knows. In most instances, we self-regulate our consumption before serious adverse reactions occur. Our bodies tell us how much we can handle, and we learn to stay within that limit. But over time, we become less sensitive to caffeine’s effects, so we gradually increase consumption, to a point. This response is known as tolerance – and it varies from person to person. (Tolerance happens with alcohol and other drugs too, not just caffeine.)

Your Daily Norm: The Self-Regulating Set Point

Think back to when you first started drinking coffee or tea, or even Coke or Pepsi. You probably started with a small amount of caffeine, say one cup, and gradually drank more until you found a daily “norm,” which may be two, three, or four cups, for instance. You may have even tried more, but scaled back to fewer cups. However much you consume, your daily norm is a measure of your set point – a level of preferred stimulation.

Leveling Off: How Tolerance Works

The brain likes balance. It’s equipped with mechanisms to keep neural activity steady. Caffeine revs up neural activity, so the brain attempts to dampen this frenzy.

Like a commander in battle, General Brain sends in neurochemical soldiers to hold down the fort. The result: you get less of a kick from caffeine. So you fight back with more caffeine, and up your consumption – until the point when General Brain and your caffeine habit reach detente. This balance becomes your set point.

In other words, when a drug’s effects are felt over long periods of time, our adaptive brain adjusts to its presence, and considers the effects to be part of normal brain function. When the drug is absent, you experience cravings. This is true of caffeine, amphetamines, nicotine, and even sugar.

Adapting to Your Personal Level of Caffeine

Think of your set point as your personal adaptation to caffeine. Your set point adjusts as your tolerance level changes. As mentioned, this is true of caffeine and other stimulants, like nicotine and alcohol, and even sugar. Some glucose, or dietary sugar, is essential to normal brain functioning. When the customary balance of sugar in the brain is out of sync, this can also create cravings.

So the absence of caffeine creates cravings in habitual users. And if your habit is to always take caffeine with sugar, your brain expects and craves both the caffeine and the sugar. A daily Frappucino may deliver a double-whammy of reward – and a double-edged craving if withheld. Does this sound familiar?

One school of thought suggests brain boost is really just a result of withdrawal. That is, a caffeine-dependent brain heads into withdrawal between doses (like overnight), and the next hit of caffeine merely jumps our brains back into balance.

There may be some truth to this theory, but it doesn’t explain why both one-time and habitual users experience the same caffeine boosts, at least for certain types of behavior.

For instance, caffeine’s enhancing effects on memory, reaction time, reasoning, mood, and attention span don’t appear to diminish with tolerance (or not severely). Energy-producing or ergogenic actions, like athletics, also happen with just a single one dose. Runners still get the same performance boost whether they’re habitual caffeine users or not.

Caffeine Withdrawal: Three Symptoms in 24 Hours

According to the American Psychiatric Association, caffeine withdrawal syndrome is diagnosed when three or more of these symptoms occur within 24 hours after stopping or reducing prolonged daily caffeine use:

headache
marked fatigue or drowsiness
dysphoric mood, depressed mood, or irritability
difficulty concentrating
flu-like symptoms, nausea, vomiting, or muscle pain/stiffness

Additionally, these symptoms must cause clinically significant distress or impairment in social, occupational, or other important areas of functioning. And, the symptoms are not associated with the direct physiological effects of another medical condition (e.g., migraine, viral illness) and are not better accounted for by another mental disorder.

To avoid these symptoms, experts say to taper off gradually over a few days to a week.

Withdrawal Syndrome and Resetting Your Set Point

If you notice you’re not getting the same kick from caffeine, try resetting your set point by weaning yourself off caffeine for a while. Let the brain and body revert to their natural caffeine-free state.

But if you are addicted and quit abruptly, you may feel symptoms of withdrawal – a classic indicator of physical dependence. Headaches top the list, along with fatigue, sleepiness, brain fog, bad moods, concentration difficulty, depression, flu-like symptoms, and all out crankiness. (Painkillers like Excedrin frequently contain caffeine, so taking them to ease a withdrawal headache is like downing a “hair of the dog” cocktail for a hangover.)

Withdrawal symptoms are why many people never succeed at quitting caffeine. They can’t get past the first 24 hours without ill effects, so they return to their habit. But with caffeine, withdrawal symptoms are minor and best overcome by tapering down on consumption.

Caffeine Intervention: My Personal Reset Plan

I practice a weekly plan to reset my caffeine tolerance level. On weekdays, I drink one cup of coffee, or 100 mg of caffeine (I’m a slow metabolizer, so this is my max). But on Sunday mornings, I switch to a cup of tea, about 25 mg of caffeine. Sometimes I go wild and have two cups of tea, but that’s still half of my normal caffeine regimen. Come Monday mornings, my usual coffee dose seems to have more punch to it. Who would have thought I’d enjoy Mondays all the more? Maybe it’s all in my head, but compared to non-reset weeks, I feel perkier, happier, and rarin’ to go. [Note: This strategy may not work for everyone, and it’s not intended as medical or health advice.]

Coming up: Caffeine’s half-life, or “How long does caffeine stay in my body?”…

Caffeine Basics: Table of Contents

8. Caffeine: Addiction, Withdrawal, Disorders

January 8, 2013 By Kate Heyhoe

If quitting caffeine has been on your mind, this is the chapter to read….

Got a caffeine habit? Welcome to the human race.

Ninety percent of the world consumes caffeine every day – as coffee, tea, chocolate, soda or other buzzed-up substance.

In Asia and Russia, tea is drunk from morning to night; and coffee’s hot in Japan and Korea.
In South America, people get their fix from coffee, guarana, or yerba mate (so many choices!).
In Brazil – the world’s main coffee supplier – even toddlers drink coffee at breakfast.
Coca-Cola peps up people of all ages, in all corners of the globe.

Chocolate lovers get a caffeine-fix, too. I don’t just drink caffeine, I devour it: two bites of dark chocolate punctuate my daily lunch.

Read on to find out why caffeine is a socially acceptable, habit-forming – and some say addictive – drug. Caffeine has plenty of benefits, but it’s still a drug that can get out of control. This chapter explains these caffeine-related medical conditions (some of their symptoms may sound very familiar):

Mental health conditions can worsen when combined with caffeine, and a famous legal battle was won using the so-called “Starbucks Defense.” This chapter also covers how much caffeine is safe and when it can be lethal.

But first, the next section asks: Are you addicted to caffeine, or it just a habit?…

Caffeine Basics: Table of Contents

Caffeine: Are You Addicted?

January 8, 2013 By Kate Heyhoe

If you consume caffeine every day, in a regular fashion, you’ve either got a habit or are addicted – pick the term you prefer.

Experts quibble over whether to call caffeine addictive or just habit-forming. The difference is somewhat a matter of semantics, but not entirely.

An addiction suggests self-destructive behavior, one that poses a threat to individuals or society, as in a heroin or cocaine addiction. For most of us, caffeine doesn’t match that type of downward spiral. Caffeine’s generally not emotionally or physically destructive, though it can be in some people, and that’s when experts consider it an addiction.

Caffeine does act like other addictive substances by tripping the reward and pleasure circuits of the brain (which explains a lot about its popularity). It is undeniably habit-forming, but most of us don’t experience adverse effects from typical doses. Caffeine can even have benefits, such as lifting depression and reducing certain cancer risks, or enhancing certain mental and physical tasks.

Whatever you call it, if you’re hooked on caffeine, don’t panic: clinically speaking, caffeine is only mildly addictive or habit-forming. Most people can easily quit caffeine, if they survive the withdrawal stage. Though intense, withdrawal symptoms typically pass in a matter of days.

How has your caffeine consumption changed? If you do have a caffeine habit, chances are you now take in more caffeine than when you first started. That’s normal. It’s known as developing tolerance. When you hit that sweet spot of daily consumption, not too strong or too weak, you’ve found your setpoint, which is covered in Chapter 7.

So if you do have a caffeine jones, relax. You’re in good company. But if you’ve not developed or don’t want a caffeine habit, some experts say there’s no reason to start one.

Caffeine: Deep Addiction or Mild Dependency?

It’s not easy to tell if someone’s on caffeine.

Caffeine’s not like alcohol; it may elevate your mood, but people don’t get giddy or use it to escape from their troubles. Caffeine doesn’t make you slur your words or walk funny.

It’s typically used to sustain or enhance functionality. We trust our lives to people on caffeine: airline pilots, teachers, firefighters, even the President of the United States. In dangerous situations, we might even prefer that these people be on caffeine, to boost their alertness and performance.

Caffeine is also self-regulating, as discussed earlier, which prevents most of us from spiraling into dramatically destructive scenarios. Once our hands start to shake, we turn off the caffeine tap.

True enough. But caffeine does have a real effect on reward circuits of the brain, one that is consistent with addiction. Breaking the caffeine habit includes the same physical and mental withdrawal symptoms that define a substance as addictive. When your hands shake, yet you’re still pouring caffeine, that’s a sign your habit is out of control.

Let’s revisit what caffeine does to our neural wiring: Caffeine stimulates dopamine, a source of feel-good effects. According to some experts, it does so in areas of the brain separate from where cocaine and harder stimulants activate the neural wiring. So, caffeine activates some reward circuits, but it may do so in a manageable way.

Perhaps it’s best to view caffeine as a mildly addictive substance, one that presents benign effects or adverse risks, depending on the user and quantity ingested. And keep in mind that caffeine is biphasic: low to moderate doses create profoundly different effects from those of high doses.

Symptoms of Caffeine Addiction

What are the symptoms of caffeine addiction? As the next section shows, there is a beast known as Caffeine Use Disorder, and you only need three symptoms to qualify…

Caffeine Basics: Table of Contents

Caffeine Addiction Symptoms

January 31, 2013 By Kate Heyhoe

AddictionShip When does caffeine cause someone to lose control? For many of us, caffeine is no more habit-forming than relying on a morning shower to wake up.

But compulsive caffeine consumption – to the point where sleep is disrupted on a regular basis, or hands tremble – suggests a physical and a psychological dependence, perhaps even a mental health disorder.

The word “addiction” is an emotionally charged grenade, packed with social stigma and misconceptions. Many health professionals now use the term disorder, as in “Caffeine Use Disorder”– a condition where sufferers continue to use caffeine, even though it adversely affects them in some way. (It’s also been called caffeinism.)

But Caffeine Use Disorder isn’t fully recognized – yet. When the bible of addiction, The Diagnostic and Statistical Manual of Mental Disorder by the American Psychiatric Association, updated the 2013 edition (DSM-5), it placed Caffeine Use Disorder in the “conditions for further study” category. More scientific studies are needed, said the task force. Because caffeine is so commonly used, and to prevent over-diagnosis, Caffeine Use Disorder needs to have a higher threshold of diagnostic criteria than those used for other abuse substances.

Nevertheless, the proposed definition for Caffeine Use Disorder is illuminating. It identifies 9 symptoms, and says the first three or more are needed to present a diagnosis of Caffeine Use Disorder. Some of us may recognize particular symptoms in ourselves, such as: a strong craving for caffeine; unsuccessful efforts to cut back or stop caffeine use; and tolerance marked by the need for more caffeine to reach the same effect. See if any of these conditions apply to you or someone you know.

Caffeine Use Disorder: 3+ Symptoms

You need at least the first three symptoms (within a 12-month period). Plus, there must be a problematic pattern of caffeine use leading to clinically significant impairment or distress, according to the proposed definition for Caffeine Use Disorder.

1. A persistent desire or unsuccessful efforts to cut down or control caffeine use.

2. Continued caffeine use despite knowledge of having a persistent or recurrent physical or psychological problem that is likely to have been caused or exacerbated by caffeine.

3. Withdrawal, as manifested by either of the following:

a. The characteristic withdrawal syndrome for caffeine.

b. Caffeine (or a closely related substance) is taken to relieve or avoid withdrawal symptoms.

4. Caffeine is often taken in larger amounts or over a longer period than was intended.

5. Recurrent caffeine use resulting in a failure to fulfill major role obligations at work, school, or home (e.g., repeated tardiness or absences from work or school related to caffeine use or withdrawal).

6. Continued caffeine use despite having persistent or recurrent social or interpersonal problems caused by or exacerbated by the effects of caffeine (e.g., arguments with spouse about consequences of use, medical problems, cost).

7. Tolerance as defined by either of the following:

a. A need for markedly increased amounts of caffeine to achieve desired effect.

b. Markedly diminished effect with continued use of the same amount of caffeine.

8. A great deal of time is spent in activities necessary to obtain caffeine, use caffeine, or recover from its effects.

9. Craving or a strong desire or urge to use caffeine.

Having these symptoms is no guarantee you’ve got a caffeine disorder, and this is not intended to be medical advice. But if you think your caffeine habit is disrupting your life, you may want to consult your doctor.

Coming up: Quitting caffeine? Get prepared for some painful withdrawal symptoms…

Caffeine Basics: Table of Contents