Not only do foods have an inherent post-digestive temperature but different foods also tend to generate more or less body fluids. Therefore, in Chinese medicine, all foods can be described according to how damp they are, meaning dampening to the human system. We need a certain amount of dampness to stay alive. Dampness in food is yin in that dampness nourishes substance, which is mostly wet and gushy. However, some foods are excessively dampening, and since it is the spleen, which avers dampness, excessive damp foods tend to interfere with digestion.
According to Chinese Five-element theory, dampness is associated with earth. Fertile earth is damp. The flavor of earth according to Chinese Five-element theory is sweet. The sweet flavor in inherently damp and also is nutritive. In Chinese medical terms, the sweet flavor supplements Qi (the function of an organ) and the blood. When one looks at a Chinese medical description of various foods, one is struck by the fact that almost all foods are somewhat sweet. On reflection, this is obvious. We eat to replenish our body function and blood; therefore most foods are sweet and fulfill the replenishing function. All grains, most vegetables, and most foods eaten by humans are sweet, no matter what other of the five flavors they may also be. However, excessive intake of sweet foods, instead of energizing the spleen, overwhelms and weakens it. This is based on the Chinese idea that yang, when extreme, transforms into yin and vice versa. When the spleen becomes weak, it craves even more sweetness since sweet is the flavor, which strengthens it when consumed in moderate amounts. Thus, another pathological cycle is forged in many people.
Going back to dampness, the sweet flavor engenders dampness and the sweeter a food is, the more dampening it is. According to Chinese medicine, this tendency is worsened when the sweet flavor is combined with sour. Therefore Chinese medicine identifies a number of especially dampening foods. These include sweet and sour foods such as citrus fruits and juices, and tomatoes; concentrated sweets such as sugar, molasses, and honey, and wheat, dairy products, nuts, oils and fats.
Highly nutritious foods such as dairy products, meats, nuts, eggs, oils and fats are strongly capable of supplementing the body’s yin fluids and substance. However, in excess, they generate a superabundance of body fluids, which become pathologic dampness. Although to some this may appear a paradox, it has to do with healthy yin in excess becoming evil or pathological yin or dampness, phlegm and turbidity.
It is also easy to see that certain combinations are even worse than their individual constituents. Ice cream is a dietary disaster. It is too sweet, too creamy, and too cold. Ice cream is a very dampening food. Pizza is a combination of tomato sauce, cheese, and wheat. All of these foods tend to be dampening and this effect is made even worse if greasy addition, such as pepperoni, and sausage are added. In the same way, drinking fruit juices can be very dampening. Fruit and vegetable juices are another relative modern addition to the human diet. Prior to the advent of refrigeration as discussed above, juices would turn into wine or vinegar within days. Therefore when they were available in traditional societies, they were an infrequent treat. Now, we have access to tropical fruits and juices thanks to refrigeration and interstate and intercontinental transportation. However, we should bear in mind that we would not eat 4 – 6 oranges in a single sitting nor every day. When we drink a glass of orange juice, tomato juice, apple juice or carrot juice that is exactly what we are doing. We are drinking the nutritive essence of not one but a number of fruits or vegetables. This over-nutrition typically results in the formation of the pathogenic dampness and phlegm.
Meats are so nutritious and very much supplement body function and blood. They also tend to be damp in the same way. The fatter and richer meat is, the more it tends to generate dampness within the body. Amongst the common domestic mammalian meats, pork is the dampest with beef coming in second. Therefore, it is important not to eat too much meat and especially not greasy, fatty meats. Most people do fine on 2 ounces of meat, 3 – 4 times per week. On the other hand, eating only poultry and fish is not such a good idea either. Everything is this world has its good and bad points. Poultry and fish tend to be less dampening and phlegmatic, it is true, but chicken, turkey and shellfish tend to be warmer. If one eats only these meats, they run the risk of becoming overheated. I have seen this happen in clinical practice. From a Western scientific point of view, we can also say that eating too much fish may result in mercury accumulation and toxicity and overeating commercial chicken may result in too much estrogen and exposure to salmonella food-poisoning. Chinese medicine sees human beings as omnivores, and suggests that a person should eat widely and diversely on the food chain.