Archives for 2013

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

2. Natural Caffeine: Coffee, Tea, Chocolate, and Other Plants

January 2, 2013 By Kate Heyhoe

No one knows for sure when humans first consumed caffeine. Africa was the starting point for coffee, and probably fueled early man. Tea has its roots in Asia. Cacao, the source of chocolate, is native to Mesoamerica, while guarana and maté originated in South America. Kola nuts hail from Africa.

Today, we get our caffeine from the same plants, though in different forms, with complex processes ranging from simple steeping to grinding, fermenting, and roasting. Before jumping into energy drinks and caffeine-enhanced products, let’s start with the basics: caffeine in its natural forms as coffee, tea, cacao, guarana, and yerba mate.

Coffee Profile

January 2, 2013 By TW

Wild coffee plants originated in the same region where early humans may have been born: Ethiopia. Around 600 AD, the Oromo, a mountain tribe that still exists in Ethiopia, concocted a primitive “energy bar” by rolling up balls of ground coffee beans and ghee (clarified butter). Here’s an FAQ about coffee, starting with a few entertaining facts:

The green (unroasted) coffee beans carry a nutritious profile: 11% proteins, 8% sugars, 16% lipids, 4% minerals, and about 1% caffeine.
Green coffee beans are roasted and brewed into coffee as we know it.
Global coffee consumption is increasing at a rate of about 2 percent annually.

What is coffee? The tropical evergreen shrub known as Coffea produces red fruit with seeds, which we know as coffee beans. These red coffee “cherries” contain two seeds, and are plucked by hand when ripe. During processing, the seeds are removed from a pulpy outer covering, dried and roasted. Coffee plants thrive at higher elevations, from 1000 to 7000 feet depending on growing conditions and distance from the equator.

What are the different types of coffee beans? Thousands of species of coffee plants exist, but only two are the main sources of commercial coffee beans: C. arabica and C. robusta (also known as C. canephora). Arabica beans are considered more complex and smoother, while robusta beans are stronger in flavor. Robusta plants are hardier, more disease resistant, and grow at lower altitudes. Commercial beans are often named for their country of origin, roasting level, blend, and other flavor descriptors.

How much caffeine does coffee yield? Robusta beans contain twice the caffeine of arabica beans. But the actual caffeine in your cup varies depending on growing, roasting and brewing methods. In this book, we use 100 mg of caffeine per cup of brewed coffee as a standard. See the sidebars for other common examples. Decaffeinated coffee actually contains a small amount of caffeine, about 2-4 mg per cup. (Raw coffee beans contain 1-2% caffeine, by weight.)

Where does coffee come from? The world’s “Coffee Belt” runs between the Tropics of Cancer and Capricorn. Latin America grows 75 percent of the world’s coffee, Africa also produces coffee, and Southeast Asia has become an important coffee region. The top five coffee producers are, from most to least: Brazil, Vietnam, Colombia, Indonesia, and India. Colombia grows only arabica beans. Vietnam grows robusta beans almost entirely.

What else does coffee contain? Like all plants, coffee contains thousands of chemical compounds. Roasting and other processing can alter these compounds, making some more volatile and destroying others. Coffee is rich in antioxidants, which may provide health benefits separate from those of caffeine. Coffee’s nutrition profile: 11% proteins, 8% sugars, 16% lipids, 4% minerals, and about 1% caffeine.

Caffeine Basics: Table of Contents

Tea Profile

January 2, 2013 By Kate Heyhoe

After water, tea is the world’s most widely consumed beverage.

Tea originated in Asia, in the Himalayas where India and China meet. It has been drunk for more than 2000 years, and before that, the leaves were chewed. Cakes were formed of tea leaves and fat, and carried as sustenance on long journeys.

This FAQ covers the basic questions about tea.

What is tea?All tea plants are varietals of the species known as Camellia sinensis, an evergreen of tropical and subtropical climates. The leaves are plucked and dried. Fermentation and the drying process determine their flavor style – as white, green, black, oolong, or pu-erh – and reflect different levels of oxidation. To make the beverage we know as tea, leaves are steeped in hot or boiling water. Most plants are trimmed into shrubs for easy plucking of the leaves, but they can reach tree height. Herb teas and other steeped infusions are not true teas, but are more accurately known as tisanes.

How much caffeine does tea yield? Tea contains 1-5% caffeine by dry weight, with traces of theophylline and theobromine, which are stimulants related to caffeine. (Caffeine in tea used to be called theine, but they are now known to be the same.) As with coffee, the growing, processing, and steeping methods impact the amount of caffeine in the cup. Most caffeine is extracted in the first minute of steeping, but longer steeping also yields more caffeine. For this book, we use 35 mg of caffeine per cup of tea, but caffeine in tea can range from 15 to 70 mg.

Where is tea grown? China and India produce nearly half of the world’s tea (and are the largest consumers). The other half comes mainly from, starting with the largest supplier, Kenya, Sri Lanka, Turkey, Vietnam, Iran and Indonesia, with some from Argentina and Japan as well.

What else does tea contain? Like coffee, tea contains hundreds of chemical compounds, including minerals and vitamins. Tea’s polyphenols, a source of antioxidants, protect cellular damage and provide health benefits. Unlike coffee, tea contains theanine, an amino acid thought to act as a neurotransmitter, and which produces feelings of relaxation despite the buzz of caffeine. Catechins in green tea are believed to prevent some cancers.

Caffeine Basics: Table of Contents

Chocolate Profile

January 2, 2013 By Kate Heyhoe

Who knew such a luscious flavor would also be a stimulating food? Ancient peoples of the Americas did.

Cacao, cocoa, and chocolate are different terms, but all come from the same tree. The word cocoa is an Anglicized version of cacao, and the word “chocolate” has roots in native languages of the Americas.

What is chocolate? Chocolate is obtained from the cacao tree, a tropical evergreen known as Theobroma cacao (which translates from Greek as “food of the gods”). Each large cacao pod yields about 40 seeds or “beans” which are fermented, dried, and roasted. They’re then processed into cocoa solids, non-alcoholic cocoa liquor (a mix of solids and fat), and cocoa butter, the essential ingredients in chocolate products. Cocoa butter is the fat, with no caffeine or other stimulants. Cocoa liquor and solids are processed into eating chocolates and cocoa powders, sometimes with cocoa butter added back in.

What are the typical types of eating chocolate? Solid chocolate is basically finely ground cocoa solids suspended in cocoa butter. The more solids, the darker the chocolate, and the more stimulants contained. Milk chocolate includes milk and sugar, with less cocoa liquor or solids. White chocolate isn’t true chocolate; it contains cocoa butter and no cocoa solids or liquor.

Many dark chocolate bars promote the high percentage of cacao on their label, as in 72% chocolate (the combined weight of the cocoa solids and cocoa butter; the rest is usually sugar). Mass market chocolates often contain almost no real cacao, as little as 10% chocolate liquor which is the minimum required by U.S. regulations.

Cocoa powder is dried cocoa liquor, ground and unsweetened, and used in cooking and beverages. Instant cocoa powder has sugar added. Unsweetened chocolate is mainly for baking and cooking, and is known as bitter, baking, or unsweetened chocolate. Semi-sweet or bittersweet chocolate contains a high percentage of cocoa liquor and solids, and some sugar. Cocoa nibs, or cacao nibs, are the crunchy inner bits of roasted cocoa beans, and are added to recipes for texture and flavor.

Where does chocolate come from? Cacao trees are native to tropical rainforests in South and Central America, but now grow in equatorial zones around the globe. West Africa produces 70% of the world’s cacao, led by Ivory Coast, and followed by Ghana, Nigeria, and Cameroon. Indonesia is the world’s second-largest producing country. Producers in the Americas include Brazil, Ecuador, Dominican Republic, Colombia and Mexico.

How much caffeine does chocolate contain? A 1-ounce portion of chocolate averages about 20 mg of caffeine and 130 mg of theobromine; the combined effect is similar to that of a cup of tea with 40 mg of caffeine. Why? Chocolate contains a small amount of caffeine, and seven to ten times more theobromine than caffeine. Caffeine is the more potent of the two stimulants, but theobromine’s greater quantity makes it the predominant buzz in chocolate. Together they pack a punch: the combined impact of caffeine and theobromine in chocolate is roughly twice that of caffeine alone. (Theobromine also occurs in small amounts in tea, guarana, mate, and kola nut; and when caffeine is metabolized by the liver, it releases theobromine as a byproduct.)

What else does chocolate contain? Some people say they’re addicted to chocolate, and there may be some truth to that. Chocolate sparks several feel-good chemicals in the brain. Anandamide is a mood-altering substance in chocolate, and also occurs naturally in the brain. It’s related to THC, the psychoactive compound in marijuana. Chocolate causes the brain to release the neurotransmitter phenylethylamine (PEA), known as the love-drug because it’s released when we fall in love. Chocolate has a small amount of tryptophan, which stimulates serotonin, and in high quantities promotes good feelings. Flavenoids and antioxidants in chocolate have been linked to cardiovascular health benefits.

Caffeine Basics: Table of Contents