Emotional Biochemistry

Like it or not, emotions share some very real biochemical links with your nervous, endocrine, immune and digestive systems. Isn’t it time you learned something about how your body responds to what you feel—and vice versa?

Hand shows the brain in the sun and sky.

Psycho means mind. Soma means body. The term psychosomatic, which we’ve been taught to associate with “imaginary” illnesses, in fact refers simply to the physiological connection between the mind and the body – a connection that is seeming more concrete and evident by the day. Science is now showing us with increasing clarity that our feelings and thoughts can help make us sick (or well) in a variety of ways that are definitely not “all in our head.”

For years now, we’ve been hearing that stress is bad for us, but beyond a vague idea that near-constant surges of cortisol and adrenaline can throw our bodies off balance, and maybe make us feel depressed, few of us have had a very clear sense of why that is. Nor have we heard much about how emotions such as grief, anger, fear, joy – or mental states such as mindfulness, contemplativeness and relaxation – might impact our biochemistry.

But this lack of knowledge is certainly not for lack of intriguing scientific evidence. Back in the 1980s, a group of research scientists – including molecular biologist Candace Pert, neuroanatomist Miles Herkenham at the National Institute of Health and neuroscientist Francis Schmitt at the Massachusetts Institute of Technology, among others – began radically changing the scientific community’s ideas of the way the human body works. Although much of their work was considered radical and controversial at the time, they eventually succeeded in turning a great deal of accepted science on its head. For one thing, they proved that a wide variety of “information-carrying substances” once thought to move only tiny distances between synaptic connections in the brain, in fact travel much farther, hooking up with specific cell receptors in distant locations.

They also identified the means by which emotions cause the bodywide release (and take-up) of all sorts of information-carrying molecules, often in areas with no electrical neurons. These chemicals, known as ligands (most of which fall into the giant class of chemical messengers called peptides) perform a vast range of functions. They travel through our extra-cellular fluids and hook up with specific, highly selective receptors located on cells throughout the body. Once attached, they impart molecular messages that can dramatically impact our physiological functioning at the cellular and systemic levels.

Thanks to new imaging technologies, research scientists have now been able to demonstrate how thoughts and emotions cause distinct neuron-firing patterns within various parts of the brain. They can also observe how these patterns coincide with chemical releases and reactions throughout the body.

The science behind all this is fascinating, and the conclusions are staggering. It turns out that biochemical reactions to mental and emotional stimuli – your everyday thoughts and feelings – occur not just in the brain but also, often simultaneously, in virtually every system of your body. We also now know that the brain and nerves, and the immune, endocrine and digestive systems (historically treated as totally distinct areas of medical specialty) are in fact capable of releasing and receiving many of the same peptides. Thus, all these systems are inextricably linked in a sort of secondary, chemically based nervous system, one that is intimately connected with (but not exclusively controlled by) the electrically based central nervous system with which most people are more familiar.

Such understandings are radically changing perceptions of just how intimately connected our bodily systems are, how they should be medically treated, and how responsive they can be to mental and emotional stimuli. These new insights are also shedding light on how certain complex conditions, such as chronic fatigue, fibromyalgia and lupus can affect so many areas of the body at once.

Because the research in this area is coming fast and furious, most doctors and scientists are still cautious about drawing hard and fast conclusions about it. But one thing is certain: the mind-body connection is real, powerful and – if you care about safeguarding and maximizing your health – definitely worth knowing about.

The Science Behind the Body-Mind

If you even remotely grasp the roles played by peptides, cell-receptors and synapses in creating your biochemical profile, and you understand generally how emotion both catalyzes and is catalyzed by them, then you are part of a small but growing group of people getting in on the front end of one of the most interesting stories to hit health-and-wellness circles this century.

Unfortunately, it’s also one of the most underreported stories in recent memory. True, articles on related topics appear regularly in scientific journals, and even in popular magazines such as Smithsonian and Scientific American. The neurological and biochemical concepts are explained and referenced in excruciating detail in books with intriguing names such as The Molecules of Emotion, The Feeling of What Happens and The Synaptic Self. But the concepts aren’t easily simplified, and thus are rarely synthesized in the general media. Nor do they have much of a toehold in the curriculum of most medical schools. Thus, most conventional doctors are largely unaware of the vast implications such insights might have for our health and life choices.

So how does one learn about how this system works? The best way is to begin studying the mechanisms by which experiences, thoughts and emotions are translated into chemical expressions or “codes” by our bodies, and to then explore how this information is communicated through – and subsequently affects – our various bodily systems. The books and magazines listed in the Resources section below are a good place to start, but here’s a super simplified version of the scenario:

Let’s say you have an emotionally charged experience or memory. That experience activates the brain’s limbic system, where it gets filtered and associated with other information and catalyzes a chain-reaction release of ligands (peptides, hormones, etc.). In cases of bodily sensation or touch, the body’s neuronal circuits can also be directly activated, with a peptide reaction proceeding from the body’s surface to the spine and then traveling to the brain and becoming part of conscious awareness.

So we know that our experience, physical or emotional, releases peptides. But once these peptides have been released, what do they do? They start swimming. If you were to watch this process under an electron microscope you would be able to see individual peptides heading directly for their target receptors, much like sperm cells wiggling toward egg cells, but much faster. Unlike sperm, though, which are all intent on a single egg, peptides fan out toward hundreds or thousands of receptor cells.

In her book Molecules of Emotion: The Science Behind Body-Mind Medicine, celebrated molecular biologist and psychoneuroimmunologist Candace Pert, Ph.D., notes that while explanations of the way ligands and receptors unite typically employ the image of a key fitting into a lock, “a more dynamic description of this process might be two voices – ligand and receptor – striking the same note and producing a vibration that rings a doorbell to open the doorway to the cell.” What happens next, she says, “is quite amazing.”

“The receptor, having received a message, transmits it from the surface of the cell deep into the cell’s interior, where the message can change the state of the cell dramatically. A chain reaction of biochemical events is initiated as tiny machines roar into action and, directed by the message of the ligand, begin any number of activities – manufacturing new proteins, making decisions about cell division, opening or closing ion channels, adding or subtracting energetic chemical groups such as the phosphates – to name just a few. In short, the life of the cell, what it is up to at any moment, is determined by which receptors are on its surface, and whether those receptors are occupied by ligands or not. On a more global scale, these minute physiological phenomena at the cellular level can translate to large changes in behavior, physical activity, even mood.”

This is serious business. How much of a particular peptide you have in your system and whether or not it is filling the receptors on various cells can impact everything from how efficiently your metabolism runs, to how you digest your lunch, to whether or not you are vulnerable to a cold or virus.

The kicker, of course, is this: How much of a particular peptide you have available and active in your body is directly impacted by, among other things, your emotional experiences.

The need for more conclusive research into this area is critical, but it seems evident that the implications are important enough to consider now, as we evaluate how our emotional lives and stress levels might be directly affecting our health in both the short and long term. We should also think about the potential importance and value of stress-reducing, life-enhancing activities like meditation, yoga, bodywork, massage, personal development and spiritual work, relaxation, time with loved ones, etc.

It seems clear, in any case, that in developing our personal health and wellness plans, we cannot afford to overlook the biochemical impacts that our emotional lives are likely to have on our physical experiences and outcomes.

This article has been updated. It was originally published online on November 1, 2003.

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