Good morning! Time to wake up, roll out of bed, and sleepwalk into the kitchen for a cup of coffee. Good afternoon! Time for a moderate glass of whiskey or wine to soothe away the tensions of the day. Good grief! Your lover has left. Time for chocolate, lots of chocolate, to soothe the pain.

Good night! Time for milk and cookies to ease your way to Dreamland. For centuries, millions of people have used these foods in these situations, secure in the knowledge that each food will work its mood magic. Today, modern science knows why.

Having discovered that your emotions are linked to your production or use of certain brain chemicals, nutrition scientists have been able to identify the natural chemicals in food that change the way you feel by:

• Influencing the production of neurotransmitters
• Hooking onto brain cells and changing the way the cells behave
• Opening pathways to brain cells so that other mood-altering chemicals can come on board

The following sections describe chemicals in food most commonly known to affect mood.

Alcohol

Alcohol is the most widely used natural relaxant. Contrary to common belief, alcohol is a depressant, not a mood elevator. If you feel loosey-goosey and exuberant after one drink, the reason isn’t that the alcohol is speeding up your brain; it’s that alcohol relaxes your controls, the brain signals that normally tell you not to put a lampshade on your head or take off your clothes in public.

In here, it’s enough to say that many people find that, taken with food and in moderation — defined as one drink a day for a woman and two for a man — alcohol can comfortably change one’s mood from tense to mellow.

Anandamide

Anandamide is a cannabinoid, a chemical that hooks up to the same brain receptors that catch similar ingredients in marijuana smoke. Your brain produces some anandamide naturally, but you also get very small amounts of the chemical from (what else?) chocolate.

In addition, chocolate contains two chemicals similar to anandamide that slow the breakdown of the anandamide produced in your brain, thus intensifying its effects. Maybe that’s why eating chocolate makes you feel very mildly mellow.

Not mellow enough to get you hauled off to the hoosegow (jail) or to bring in the Feds to confiscate your candy; just enough to wipe away the tears of lost love. (Don’t worry; you’d need to eat at least 25 pounds of chocolate at one time to get any marijuanalike effect.)

Caffeine

I don’t think that I have to tell you that caffeine is a mild stimulant that:

• Raises your blood pressure
• Speeds up your heartbeat
• Makes you burn calories faster
• Makes you urinate more frequently
• Causes your intestinal tract to move food more quickly through your body

Nor do I have to tell you that caffeine is a mood elevator. Although it increases the level of serotonin, the calming neurotransmitter, it also hooks up at specific receptors (sites on the surface of brain cells) normally reserved for another naturally occurring tranquilizer, adenosine (a-DEN-o-seen).

When caffeine latches on in place of adenosine, brain cells become more reactive to stimulants such as noise and light, making you talk faster and think faster. Lately, athletes who take coffee before an event have reported that it also improves performance in some endurance events.

However, how people react to caffeine is a highly individual affair. Some can drink seven cups of regular (“with caffeine”) coffee and still stay calm all day and sleep like a baby at night. Others — me, for instance — tend to hop about on decaf. Or as my friend often says, “What was the blur that just went through the living room?”

Perhaps those who stay calm have enough brain receptors to accommodate both adenosine and caffeine, or perhaps they’re more sensitive to the adenosine that manages to hook up to brain cells. Nobody really knows. Either way, caffeine’s bouncy effects may last anywhere from one to seven hours.

I know that I can count on missing a night’s sleep when I have real (as opposed to decaffeinated) coffee after 5 p.m. Espresso at dinner? I’ll still be awake when the birds get up the next morning. Table below lists some common food sources of caffeine.

Food	Amount of Caffeine (mg)
5-ounce cups
Coffee, regular, drip	80–150
Coffee, regular, instant	40–108
Coffee, decaffeinated	1–6
Tea	20–110
Tea, instant	25–60
Cocoa	2–50
12-ounce can
Soft drinks	30–72
8-ounce container
Chocolate milk	2–7
1-ounce serving
Milk chocolate	1–15
Semisweet chocolate	5–35
Bitter (baker’s) chocolate	26

George M. Briggs and Doris Howes Callaway, Nutrition and Physical Fitness, 11th ed. (New York: Holt, Rinehart and Winston, 1984); Current Medical Diagnosis and Treatment, 36th ed. (Stamford, CT: Appleton and Lange, 1997)

Tryptophan and glucose

Tryptophan is one of the amino acids, a group of chemicals commonly called the building blocks of protein. Glucose, the end product of carbohydrate metabolism, is the sugar that circulates in your blood, the basic fuel on which your body runs.

Milk and cookies, a classic calming combo, owe their power to the tryptophan/glucose team. Start with the fact that neurotransmitters dopamine, norepinephrine, and serotonin are made from the amino acids tyrosine and tryptophan, which are found in protein foods (like milk).

Tyrosine is the most important ingredient in dopamine and norepinephrine, the alertness neurotransmitters. Tryptophan is the most important ingredient in serotonin, the calming neurotransmitter. All amino acids ride into your brain like little trains on tiny chemical railroads.

But Mother Nature — clearly a party animal! — has arranged the switches so that your brain makes way for the bouncy tyrosine train first and the soothing tryptophan train last. That’s why a high-protein meal heightens your alertness. To move the tryptophan train up the track, you need glucose, and that means you need carbohydrate foods (like those cookies).

When you eat carbs, your pancreas releases insulin, a hormone that enables you to metabolize the carbs and produce glucose. The insulin also keeps tyrosine and other amino acids circulating in your blood so that tryptophan trains can travel on plenty of open tracks to the brain.

With more tryptophan coming in, your brain can increase its production of soothing serotonin. That’s why a meal of starchy pasta (starch is composed of chains of glucose molecules) makes you calm, cool, and kind of groovy.

The effects of simple sugars such as sucrose (table sugar) are more complicated. If you eat simple sugars on an empty stomach, the sugars are absorbed rapidly, triggering an equally rapid increase in the secretion of insulin, a hormone needed to digest carbohydrates.

The result is a rapid decrease in the amount of sugar circulating in your blood, a condition known as hypoglycemia (hypo = low; glycemia = sugar in the blood) that can make you feel temporarily jumpy rather than calm.

However, when eaten on a full stomach — dessert after a full meal — simple sugars are absorbed more slowly and may exert the calming effect usually linked to complex carbohydrates (starchy foods).

So some foods, such as meat, fish, and poultry, make you more alert. Others, such as pasta, bread, potatoes, rice and other grains, calm you down. The effect of the food depends on its ability to alter the amount of serotonin available to your brain.

Phenylethylamine (PEA)

Phenylethylamine — sometimes abbreviated PEA — is a natural chemical that your body releases when you’re in love, making you feel, well, good all over. A big splash occurred in the late 1980s when researchers discovered that chocolate, the food of lovers, is a fine source of PEA. In fact, many people think that PEA has a lot to do with chocolate’s reputation as the food of love and consolation.

Of course, to be fair about it, chocolate also contains the mood-elevator caffeine, the muscle stimulant theobromine, and the cannabinoid anandamide. What is there to say other than, “Hey, can you please pass that box of chocolates down to this end of the table?

Using Food to Manage Mood

No food will change your personality or alter the course of a mood disorder. But some may add a little lift or a small moment of calm to your day, increase your effectiveness at certain tasks, make you more alert, or give you a neat little push over the finish line.

The watchword is balance:

• One cup of coffee in the a.m. is a pleasant push into alertness. Seven cups of coffee a day can make your hands shake.

• One alcohol drink is generally a safe way to relax. Three may be a disaster.

• A grilled chicken breast (white meat, no skin) for breakfast — yes, breakfast — on a day when you have to be on your toes before lunch can help make you sharp as a tack.

• Got an important lunch meeting? Order starches without fats or oils: pasta with fresh tomatoes and basil, no oil, no cheese; rice with veggies; rice with fruit. Your aim is to get the calming carbs without the high-fat food that slows thinking and makes you feel sleepy.

In this, as in other aspects of a healthy life, the point is to make sure that you use the tool (in this case, food), not the other way around.