Many people have had this experience: when stepping onto familiar soil (hometown or places where they once lived), they will actively seek out restaurants they visited before. They want to relive the experience by eating local foods or special snacks. In a foreign land, once they find a restaurant serving the food of "old time," they will do anything to try it.
When I discuss this with a friend, she says this is the gut-brain axis effect. The gut-brain axis is a relatively new theory that posits the gut microbiota as a bridge for communication between the brain and the digestive system. The microbiota in the gut influences the secretion of gut hormones, which enter the bloodstream and circulate to the brain, affecting its function. Therefore, it is believed that the gut influences brain function, further impacting a person's physical and mental health (this is a highly simplified interpretation of the gut-brain axis).
After all, the brain is the headquarters of the body.
I read somewhere that the brain's appearance in the head is similar to the appearance of the intestines in the abdomen — both seem convoluted — so they must have similar functions ... of thinking (hehe).
As for the gut-brain axis and how it works, I'll leave that to the experts for explanation and research. I want to (attempt) to give it a psychological explanation, more precisely, a psychologically related interpretation.
Clothing, food, shelter, and transportation are basic human needs indispensable for individual survival. Suppose we include the reproduction of the species. In that case, we can add relationships and sex. Clothing, food, shelter, and transportation are ordinary, right? We need them every day, but their extraordinariness resides in their ordinariness.
Take eating as an example. Our tastes and preferences for food are formed through daily life, and taste buds may also have imprint effects and memory. What we eat in childhood often determines our food preferences for our whole life. I have lived in Canada for 25 years, but I have a Chinese stomach; as I often say, I can't stand eating Western food for two days straight. After two days, I will try to find a Chinese restaurant or buy/make Chinese food for myself. Similarly, to make a more specific classification, a Chinese might have the Sichuan stomach, Shandong stomach, Northeast stomach, etc. You probably have French stomachs, Italian stomachs, Japanese stomachs, Thai stomachs, Indian stomachs, and so on.
Besides sustaining life, food is also a medium that connects us with places, the past, our loved ones — family, friends, and partners — and all the emotions in these relationships!
If you close your eyes and imagine a kind of food you like and then recall the memories associated with that food, will there be many things----memories and related feelings come to your mind? Do you feel like you want to relive some of the memories? Desire to be some of the people again? Or are strong emotions appearing?
Take dumplings as an example. In northern China, people make and eat dumplings on Chinese New Year, when a person returns from leaving. Dumpling-making is an art; usually, it needs at least two persons' cooperation; you must make dough and filling, roll out wrappers, wrap, boil, and eat dumplings. Many conversations and interactions occur during the process, especially when the whole family makes them together. And the emotions involved! Laughter, jokes, arguments. In this ordinary life, day by day, year after year, life passes by amid the hustle and bustle. Happiness and sadness, hope and despair, waiting and disappointment, reunion and separation, success and failure......all of these happen alongside daily life, including eating and food.
When I left home for university at 16 years old, my mother stuffed food into my luggage. When my parents came to visit me, they brought the indigents to make the hometown food for me. Every time I go home, I keep eating and gaining weight and memories of love from my family and friends are getting fatter and fuller, too. During loneliness or feeling empty, we sometimes turn to food to fill the void.
Food and eating are very important for the Chinese (and everybody); much attention is paid to what to eat, where to eat, and the eating ceremonies. There are occasions when food's symbolic function is at the wheel while the survival function of food has taken a back seat. Chinese are proud of their colourful culinary culture. Several years ago, they made a documentary about it called "A Bite of China" (舌尖上的中国).
Food is closely related to our feelings and emotions, especially love.
So, when you are eating a particular food, especially one associated with old times, from the moment you hear, see, smell, and taste it, it begins to evoke related memories and emotions (sometimes in the subconscious). Your feelings will affect the digestive system's reaction. The digestive tract is an emotional organ. When a Chinese feels a strong emotion, especially a strong and negative one, they may describe it as "tumbling of the stomach and intestines" (翻肠倒肚）, and in English, when somebody feels nervous and worried, he might say, "I have butterflies in the stomach." When food stimulates the reaction of the digestive system, rich signals will be sent to the brain, which will influence your thinking, feeling, and behaviour. ... Are they related to the gut microbiota? Perhaps it doesn't matter much. Perhaps... it does matter because the microbiota we raise since infancy might prefer certain foods. Then it affects the secretion and endocrine of the digestive tract. The hormones and nerve signals are then transmitted to the brain through the bloodstream and nervous system. With the day-by-day training of the gut-brain connection, some foods become your favourite, while some kinds of food make you feel disgusted when you hear or see them.
Therefore, when you seek old-time delicacies, you are looking for a bite of nostrostalgia
Sometimes, when we finally find a food we've been craving for, it doesn't taste as delicious as we remember anymore. We tell ourselves it is because it's not authentic or we have eaten too many more delicacies, so we naturally feel they are less delicious than before.
It may be because the past cannot be repeated, although we have found the food.
After many years, having gone through so much, the old-time friends have been lost, and we cannot repeat the old-time happiness anymore. It is true nostalgia,
(Today, after talking about food with a patient, these thoughts linger in my mind.)
（FW）