The Influence of Thoughts on Digestion
Thinking about food is delightful. Besides hunger, such thoughts could be brought on by images of food (food advertisements), discussions about food (friends planning a dinner party), the smell of food (walking past a bakery) and so on. The ambience of a dining place (a restaurant or a picnic spot) can conjure a great appetite. Eating starts in your mind.
The influence of thoughts on appetite and food choices
Such thoughts are more important than most people realise. If you have good instincts - which will come if you eat well and enjoy good health - your thoughts about food will guide you to eat what you need. For example, if you think of eating fruits, your body may need more vitamin C. If you feel like eating something salty, you may need minerals. And so on.
Physiological changes triggered by thoughts about food
Thoughts about food stimulate the appetite. In turn, this will trigger a whole series of changes to prepare the body for digestion and assimilation:
There is an outpouring of digestive enzymes like saliva in the mouth, gastric juices and hydrochloric acid in the stomach, intestinal secretions, pancreatic enzymes and alkali from the pancreas and bile from the gallbladder;
The intestines move actively in waves of contractions and relaxations;
Peptides, which aid digestion, are released to regulate intestinal activities;
Insulin and glucagon are released to regulate glucose levels;
Leptin is released to regulate appetite.
The Mind-Gut Connection: Preparing for Digestion
This link between the mind and gut is critical to healthy digestion. Children are particularly vulnerable to poor perception from bad experiences. So it is important to make food delightful and fun for them. Forcing children to eat certain foods, or scolding them for not wanting to eat, can worsen their appetite and leave deep psychological scars.
The book and movie, Like Water for Chocolate (by Mexican novelist Laura Esquivel) is a love story with a strong food theme. In one memorable scene, the heroine of the story was feeling very sad while preparing a meal and later, when people later ate her food, they all started crying uncontrollably. This is fantasy and exaggeration, of course. But it is based on a common belief that the mood of a cook can affect the food that he or she prepares.
The Mood of the Cook: Affecting Food Quality
There could be an element of truth there: a cook who is in a bad mood could certainly be more careless, resulting in the food being too salty, too spicy, overcooked or otherwise less optimal. So if you are the one preparing food for your family, keep yourself happy. Don't cook if something "bad" happened and you cannot control your mood. Have your family members eat out for a change. Or, if it cannot be helped, minimise your cooking and prepare something really simple. If you have a helper who prepares your food, don't scold or upset her, especially before she cooks.
Just as the cook should be happy, so should the diners. Digestion is regulated by a network of nerves, which, in turn, is regulated by two opposing systems - the parasympathetic nervous system that controls the "rest and digest" process and the sympathetic nervous system that controls the "fight or flight" response. Therefore, digestion starts from your brain. Your thoughts will greatly influence your digestion.
The Role of Thoughts in Digestion: Mindful Diners
Digestion is a parasympathetic process that requires a calm and relaxed mind and body. When you are stressed and unhappy, your overactive sympathetic nervous system effectively shuts down the digestive process. This is why you lose your appetite when you are unhappy.
At the same time, people who feel depressed often have an urge to eat, even if they don't have much of an appetite. This is a subconscious attempt to make oneself happy by eating. Carbohydrates give you glucose, which releases dopamine. Proteins give you the amino acid tryptophan, which produces serotonin. Both dopamine and serotonin make you feel happy. Because of this, chronic depression often leads to a craving for "comfort foods", resulting in weight gain.
Stress and Digestion: Shutting Down the System
Stress can make you vomit. Formula One grand prix drivers are known to vomit in their helmets due to the extreme stress of high-speed racing! Stress can wreak havoc even if you're doing everything else "right".
The body's response to stress is to "fight or flight". As part of this response, your digestive system shuts down to divert blood for your heart and muscles to deal with the stress. At the same time, you throw out your contents to lighten your body load. This is why stress can cause both vomiting and diarrhoea.
The following are some of the bodily changes that take place when you are under stress:
- Blood flow to the intestines decreases by four-fold;
- Enzymes output decreases by as much as 20,000-fold;
- Oxygen supply to your entire gastrointestinal tract is decreased;
- Nutrient absorption is decreased while the body excretes nutrients, particularly water-soluble vitamins like vitamins C and B complex and minerals like calcium.
The Calming Practice: Prayer and Mindful Eating
Many religions have a practice of saying a thanksgiving prayer before meals. Whether or not you are religious, that short prayer or even a pause of silence will certainly put you in a calmer state of mind to prepare your body for eating.
And while you are eating, don't do other things like read or, worse still, work, walk or run. Focus on your food. Sit down and eat in a relaxed manner. Light conversation with friends is okay because friendly social contact is also relaxing. Avoid heated discussions about politics, religion or other contentious issues.
Importance of managing stress for optimal digestion
Acute stress is normally short-lived. Provided it does not occur too frequently, it is not a problem as the body quickly resumes normal functions. Many people today, however, suffer from chronic low-level stress. It is vital, therefore, to manage your everyday stress. This will improve your digestion of food and assimilation of nutrients. In turn, it will reduce your risks of all diseases.
This content is adapted, with permission, from Book 1 of 2 : The Wonders of Nutrition by Dr Ang Poon Liat. MBBS, M.MED (PAED), MRCP (UK PAED), FAMS, MD.