How the hidden conversation within our bodies impacts our mood, our choices, and our overall health.
By: Emeran Mayer MD
Brilliant book to help understand the mind body connection, the hormones and our microbes within our bodies.
To be aware of latest science putting all of this together to help us live healthier lives for longer. This book is a fantastic read to learn more about yourself.
I will outline some sections within the book I found fascinating and interesting to bring to you. As always if this review helps you, and you’d love to know more – then please go out and buy or borrow this book – you’ll be amazed…
The mind body connection:
The lining of your gut is made up of endocrine cells, different types of hormones that can be released into the bloodstream when called upon.
The gut is the largest storage facility for serotonin in our body. (ninety-five percent actually).
Serotonin is a signalling molecule that plays a crucial role within the gut-brain axis, such as coordinating contractions through the digestive system, and vital functions – sleep, appetite, pain and mood.
The gut is connected to the brain through thick nerve cables that can transfer information in both directions and through communication channels that use the bloodstream: hormones and inflammatory signaling molecules produced by the gut signaling up to the brain, and hormones produced by the brain signaling down to the gut.
These help immune system, feeling full after a meal, nausea, discomfort and feelings of well-being.
The little brain in your gut
Flow chart of eating:
When you start to chew your stomach starts to fill with concentrated hydrochloric acid (like battery acid)
When food hits the stomach (preferably chewed up a lot), your stomach breaks the particles into tiny pieces.
Your pancreas and gallbladder are preparing the small intestine by injecting bile to help digest fat and digestive enzymes.
When the stomach passes the tiny bits of food to the small intestine, the enzymes and bile break them down into nutrients that the gut can absorb and transfer to the rest of the body.
As digestion proceeds, the muscles in your intestinal walls execute contractions move the food down your digestive tract (depending on the food, the gut has more time to absorb fat and complex carbohydrates and less for sugary drinks.)
The lining of your small intestine absorbs nutrients while the large intestine sends big waves of contractions to urge a bowel movement.
In between meals your gut’s housekeeper, sweeps out anything your stomach couldn’t dissolve or break down enough (undissolved medicines or unchewed peanuts). This wave slowly travels from your esophagus to your rectum every ninety minutes, sweeping microbes from your small intestine into the colon.
This happens only when there is no food left to digest in your GI tract, mainly while you sleep, and will stop as soon as you take your first bite.
This is all mastered from your enteric nervous system (ENS) – known as your ‘second brain’ and when it comes to digestion – it’s brilliant.
Your emotional brain can mess up just about everyone of those automatic functions.
If your dinner conversation takes a wrong turn and you get into an argument with your frines, your stomach’s wonderful grinding activity is quickly turned off and instead goes into spastic contractions that no longer allow it to empty properly.
Food will stay in our stomach, contractions won’t happen, and the night cleansing of your gut will not go ahead.
This leads to a fault in the gut-brain connection, triggering false alarms, messing up your wellbeing.
How your gut talks to your brain
Twenty four hours a day, seven days a week, our GI tract, enteric nervous system, and brain are in constant communication.
And this communication network may be more important for your overall health and wellbeing than you ever could have imagined.
When the receptors on your tongue, binds to a chemical on a food item, it sends a message to your brain, and your brain constructs the particular taste from the streams of sensory information it receives from your mouth and tongue
The taste receptors on your tongue can detect five different taste qualities: sweet, bitter, savory, sour and umami.
It also detects the texture, crunchy, soft, smooth etc.
Some of these receptors are activated by specific molecules found in herbs and spices like garlic, hot chilli pepper, mustard, and wasabi, while others respond to menthol, peppermint, cooling agents and even cannabis.
Spices are great to use to enhance flavours of our meals, but also herbs are used as medicinal purposes.
Certain parts of the world use them as a part of their culture and some to provide protection against illnesses, such as common colds.
There are possible roles that have been proposed for the bitter taste receptors in the GI tract.
Their stimulation has been shown to result in the release of the gut hormone ghrelin, also known as the hunger hormone, which travels to the brain to stimulate appetite… to stimulate bitter receptors in the gut helps to release ghrelin and increase appetite.
- Think chinese herbal medicines – they are so bitter and disgusting, but are related to the activation of one or more of the gut’s twenty five bitter receptors, thereby sending healing messages to your brain and body
Adapted for survival
As we know that an overactive fight-flight system with constantly elevated stress hormones circulating through our bodies can lead to serious mental illness, including anxiety disorders, panic disorders, and depression.
It can also cause a nasty assortment of stress-sensitive physical disorders, including obesity, metabolic syndrome, heart attacks, and strokes.
This affects the gut-brain axis and can cause chronic gut disorders like irritable bowel syndrome and chronic abdominal pain.
Certain stress during pregnancy and during times when children are growing up are harmful for their brain development and can alter their brain-gut-microbiome axis.
Stress can be transmitted from one generation to the next
We know that epigenetics of our genes can affect not only cells and mechanisms that determine how our brain develops, but also our germ cells or gametes, which carry the genetic information passed onto our children.
The discovery of epigenetics ended a long running debate over the degree to which nature or nurture causes stress related diseases. Epigenetics violated everything modern biologists had believed about inheritance.
Nutrition in brain health
Rapidly advancing science: Foods are beneficial to our emotional and mental wellbeing. It may influence the way we treat anxiety disorders and depression in the future.
The brain constructs gut feelings from gut sensations;
Signals arising from the gut and its microbiome, including chemical, immune, and mechanical signals, are enclosed by vast array of receptors in the gut wall and sent to the brain via nerve pathways (vagus nerve)
The signals sent from your gut to your brain, the gut sensations, play a key part in these early experiences and, by extension, your ability to differentiate good from bad.
When your stomach was empty, it released a hormone, ghrelin, that led to an urgent feeling of hunger.
This sensation, coupled with a strong motivational drive, would be the basis of other bad gut feelings.
Gut feelings can also be associated with positive sensations, such as the warmth of feeling good after a meal, the pleasant sensation of smelling beautiful aromas.
The cycling experience in infancy of feeling full or hungry – good or bad – may lay the foundation for the moral judgements of good and bad that emerge into gut feelings later in life.
So depending if the baby was left to cry for awhile compared to being nursed and fed straight away can determine how it grows to perceive the world… Thus your earliest feelings serve as a mode for “what the world is like and what I must do to survive”
Women seem to be better at listening to their gut feelings and making intuitive decisions – this they feel is because of having experiences such as menstruation cycles, pregnancy and childbirth.
The science now says that changing your diet is not enough. You need to modify your lifestyle as well.
By having kimchi or sauerkraut for a few weeks or eliminating grains or gluten (making the gluten free industry happy), even though you are not celiac will not have any long lasting effect on your well being and health…
There’s more to the story, it’s about lifestyle change and the state you are in when you eat.
Brain’s reward system and food addiction
A number of gut hormones and signaling molecules influence activity in the dopamine reward pathway. Playing a major role in modulating motivation and sustainability of behaviours necessary to obtain the reward, like drive and motivation to forage for food (laps of the pantry)
However, this hardwiring of our brain systems related to food intake loses much of its adaptive value in the world most of us inhabit today.
In our modern industrialized society, with it’s easy access to highly palatable food and dramatically reduced levels of physical activity, the drive of the reward system can easily overwhelm the control system computing our daily caloric needs, and often has to be controlled voluntarily to avoid overeating and weight gain.
The high calorie foods rich in fat and sugar, have been proven to trigger addictive eating behaviours in both animals and humans.
Lure of comfort foods
Experiments on fifty nine healthy women:
The ratings of mood and the activation of the emotional brain regions during the negative stimulus clearly demonstrated and increase of sadness and an increase in brain reactions.
When subjects ate high fat, they had a comforting effect, speculating that the fatty acids improved the subjects mood by stimulating the release of signaling molecules from the gut, which reached emotional brain regions via the vagus nerve.
When these women regularly ate comfort foods when stressed it dampened their physiological response to stress.
The food induced stress reduction comes at a cost of weight gain and other detrimental changes in their bodies and brains.
Don’t eat when you are stressed, angry or sad.
To farm your gut microbes optimally, feeding is only half the story.
Emotions can profoundly affect the gut and the microbial environment in the form of gut reactions.
A negative emotion state will throw the gut-microbiota-brain-axis out of balance in several ways.
It’ll make your gut leakier, it activates your gut based immune system, and it triggers endocrine cells in the gut wall to release stress hormones.
It can also reduce the good bacteria – adding a behavioural change on how microbes break down food and what they send or don’t send back to the brain.
For all these reasons, no matter how conscientious you are when selecting food, and no matter what the latest fad diets you are following, feelings of stress, anger, sadness, or anxiety always turn up at your dinner table.
They can not only ruin the meal; if you eat when feeling bad, it can be bad for your gut and bad for your brain.
You should always scan your body and mind and tune into your emotions before you sit down to eat something.
If you are stressed, anxious, or angry, try to avoid adding food to the turmoil in your gut.
In addition, if you have always been an anxious person, or suffer from an anxiety disorder or depression, the influence of these negative mind states on the activities of your gut microbes when it comes to digesting the leftovers of your meal is even more pronounced, and it may be difficult to change the situation even if you are aware of it.
Enjoy your meals together
Sense of connectedness and well-being almost certainly affects the gut and influences how your gut microbiota responds to what you eat.
You may see benefits every time you eat a meal, or you may notice benefits that occur over time.
Become an expert in listening to your gut feelings
Mindfulness-based stress reduction can also help you get in touch with your gut feelings and reduce the negative biasing influence of thoughts and memories on these feeling states.
This sort of mindfulness helps to relieve disorders of the gut brain axis.
Mindfulness meditation is typically described as “non-judgemental attention to experiences in the present moment”
In order to become more mindful you will have to master three interrelated skills:
- learn to focus and sustain your attention in the present moment
- Improve your ability to regulate your emotions
- Develop greater self-awareness
Learn to feel your deep abdominal breaths, become aware of gut feelings – those associated with good and bad reactions.
How and what to feed your gut microbes
- Aim to maximize gut microbial diversity by maximizing regular intake of naturally fermented foods and probiotics
- Reduce inflammatory foods – processed and mass produced.
- Eat smaller servings at meals
- Reduce stress and practise mindfulness
- Take three to five deep belly breaths before eating
- Avoid eating when stressed, angry or sad.
- Enjoy the secret pleasures and social aspects of food
- Become an expert in listening to your gut feelings
Many people diagnosed with Parkinson’s develop GI symptoms long before the classical neurological symptoms appear.
It has long been known that nerve cells in affected brain regions contain so-called Lewy bodies – abnormal clumps of protein that interfere with nerve function.
As the earliest symptoms of constipation develop in the gut, it is possible that Parkinson’s disease begins in the gut and gradually makes its way to the brain?
Could Parkinson’s disease be a gut-brain disorder?
And could the gut’s microbiome be one of the culprits?
Based on exciting new scientific evidence, the answer to all these questions may be a yes.
Certain nerve cells in the enteric nervous system degenerate years before other Parkinson’s symptoms appear, comprising the elaborate functioning of the little brain in the gut, slowing the process and delaying the transit of stool through the colon.
A vegetarian diet, which shifts the microbiome, lowers the risk of Parkinson’s disease, for example.
So shifting away from a standard diet may help prevent the onset of Parkinson’s.
More information within the book…
Shaping a baby gut brain dialogue
Infants who were breastfed for longer responded more to a person’s body language; they had a happy body expression than those who had only been breastfed for a short time.
Recognising basic emotions like happiness or anger from facial expression and body language gives babies a fundamental tool that’s crucial to their emotional and social development.
Oxytocin promotes affiliation and bonding, suggesting that oxytocin release during nursing enhances mother-child bonding.
The hormone is released in the brains of both the nursing mother and her infant.
As I evolve in my learning and understanding of the connection of our mind and body, this book explains the ramifications of negative thoughts, stress and anxiety to our gut health.
With all the latest hype with the connection of gut health and mental health, this book is very helpful to those that are looking to nurture their overall health in their mind and body.
It’s more than just exercise and diet, and new science is really diving in deep to explore our nervous systems, hormones and cell receptors roles within our amazing bodies.
Highly recommended book