Researchers have identified more than twenty different types of endorphins. In addition to alleviating emotional and physical pain, these chemicals are involved in the regulation of blood pressure, heart rate, breathing, and body temperature. We have endorphin receptors (think of these as the loading docks of your cells) in different types of cells throughout our bodies, playing different roles. For example, in the nervous system, endorphins act as painkillers and tranquilizers, whereas in our mouths, they diminish secretions and lead to the familiar “cotton-mouth” sensation.
Endorphins also govern our attachment instinct. A mother’s attention and loving presence trigger an endorphin release in an infant’s brain. Nature didn’t forget the brains of mothers, either: mothers experience huge endorphin surges when they nurture their babies. Conversely, if a mother or other caregiver fails to respond adequately to an infant’s needs on a consistent basis, endorphins are not released in the baby’s brain. She is left to self-soothe with alternative coping mechanisms like thumb sucking, rocking, or shutting down and tuning out.
When our levels of this natural pain reliever (named for its resemblance to morphine) are low, we may find that we are highly sensitive to both emotional and physical pain. We seem to feel pain more than others do. Perhaps we cry at the drop of a hat. Stress can deplete our scanty levels of endorphins even further.
Alcohol and drugs (especially opiates), as well as drug-like components in foods such as refined flours and sugars, can attach to our brain-cell receptor sites and take the place of our natural brain chemicals. As our brain perceives these receptor sites as full, it produces less of our natural chemicals. This partly explains the vicious cycle many overeaters know so well: cravings, indulgence, relief, and more cravings.
Dopamine: Energy and Focus
Our main energizing brain chemical is called dopamine. It’s like our natural caffeine. It promotes a sense of satisfaction, drives assertiveness, and pumps up our libido. Dopamine keeps us feeling energized, upbeat, and alert. By helping us focus and concentrate, it plays a role in the learning of new behaviors. Pleasurable experiences such as dinner with a dear friend, a good tennis match, or the anticipation of a vacation tend to elevate dopamine levels.
Joyful, nurturing interactions with primary caregivers stimulate the development of dopamine receptors in the infant’s brain. Early separations, insufficient emotional and physical attention, or regular stressed interactions with caregivers can cause significant alterations in the dopamine system, including reduced dopamine production as well as a diminished number of dopamine receptors.
If you’re low in this important brain chemical, you may experience low or flat moods, including depression. You may have difficulty getting out of bed in the morning or tend to sleep long hours. You may find it challenging to concentrate and focus on tasks. Your motivation, drive, and enthusiasm for life may be low, and you may have difficulty activating yourself. You may experience boredom or apathy more often than you’d like. You may feel easily overwhelmed and inclined to procrastinate. Your brain and your life may feel cluttered.
Studies have demonstrated that 12 to 40 percent of adults in the United States are born with a gene that reduces the number of dopamine receptors. A diminished number of dopamine receptors in the brain appears to play a role in the diagnosis of attention deficit disorder. People with fewer dopamine receptors are at greater risk of engaging in substance abuse, compulsive gambling, internet and sex addiction, and compulsive overeating. Some overeaters have been born with an altered gene that also results in lower production of dopamine.
When your dopamine levels are low, you may be attracted to stimulating substances like coffee, tea, soda, chocolate, tobacco, and street drugs like amphetamines and cocaine. You may also have cravings for sweets, starches, alcohol, marijuana, and foods and drinks sweetened with aspartame. Foods high in fat, like fried foods, chocolate, cheese, and meat also increase dopamine levels, so if these are your go-to comfort foods, low levels of this chemical may be playing a role. And, as with endorphins, when our brains perceive our dopamine receptor sites as full, whether from drug-like foods or beverages or from actual brain chemicals, our natural production declines. We’re back to that vicious cycle.
Serotonin: A Sense of Well-Being
Another key brain chemical is serotonin. When you have enough of this important chemical, your mood tends to be stable (assuming your other brain chemicals are in balance). Animal studies have demonstrated that parental nurturing determines the production of serotonin. Even minor imbalances in the availability of this chemical can manifest in behaviors such as fearfulness and hyperactivity.
Serotonin deficiency is by far the most common cause of mood problems in the United States. Low serotonin levels can make you feel anxious, panicky, irritable, agitated, cranky, constantly worried, or depressed. You may act impulsively, obsessively, and perfectionistically. Your thoughts are likely to be negative, fearful, and critical. You may experience phobias, fibromyalgia, migraines, PMS, and tension in your jaw. You may suffer digestive difficulties, since a large percentage of the serotonin in your body is in your gut (which has been called the second brain). You might find it difficult to get a good night’s sleep, as serotonin is converted to melatonin, the so-called sleep hormone. Your mood may worsen with season and daylight changes, a condition called seasonal affective disorder.
Low serotonin levels play a role in food obsession, compulsive binge eating, and exercise addiction. If you find that you’re drawn to high-carbohydrate snacks in the late afternoon and evening, it may be because your serotonin production is dropping. Daylight, physical exercise, and foods containing the amino acid L-tryptophan increase serotonin levels in the brain and the body. You may crave dairy products high in this substance, like ice cream, hot chocolate, pudding, or a warm glass of milk. Marijuana and alcohol can enhance serotonin levels, and this explains why you might find yourself wanting to unwind, as the sun goes down, by smoking pot or drinking wine, beer, or your favorite cocktail. Unfortunately, overuse of marijuana and alcohol can lead to addiction and end up inhibiting serotonin production.
GABA: Soothing Emotional Eruptions
GABA, or gamma-aminobutyric acid, is probably the least-known brain chemical. It is our natural Valium, and it helps us feel relaxed. It’s called an inhibitory neurotransmitter because it turns off certain kinds of brain reactions, such as the production of excitatory chemicals like adrenaline. GABA helps to calm our emotional storms without recruiting our brain-stem areas into the all-too-familiar fight, flight, or freeze reactions. If the integrative fibers that connect our upstairs and downstairs brains are working properly, this brain chemical is released when we experience stress.
When GABA levels are low, we may experience mood disturbances and cravings for alcohol, drugs, and comfort food — particularly substances that calm us down, such as alcohol, marijuana, sedatives, sweets, and fatty foods.
Glutamine: Sweet Cravings and Good Digestion
There is one final key player worth mentioning that affects mood and food cravings. Amino acids are the building blocks of all proteins. Glutamine, the most abundant amino acid in the muscle and plasma of humans, is a stimulating, excitatory organic substance that acts like a brain chemical. Traditionally considered a nonessential amino acid, it now appears to be an essential nutrient in the body’s response to stress, injury, or illness. It is critical for optimal brain function, boosting mood, increasing alertness, and enhancing memory. It also increases libido and facilitates digestion.
Our brains can use glutamine as an emergency substitute fuel, in place of glucose, when we haven’t eaten or when our blood sugar levels are low. If we have enough of this important amino acid, we are less likely to hit the candy machine when our blood-sugar levels drop. When we are under stress, the right amount of glutamine can