Some diets can have a profound effect on emotions, especially those that cause imbalance of pH, an acidic pH, of the tissues. The tissue pH can be determined by measuring the saliva pH.
The most common acid causing foods and drinks are sugars, red meats, breads, processed and artificially flavored foods and drinks.
William Donald Kelly, DDS, and William Wolcott, wrote The Metabolic Typing Diet which describes the different metabolic types an individual can have that influence their tissue pH and various chronic illnesses, depending on which specific diet they consume.
Dr. D’Adamo’s book Eat Right 4 Your Type or Joseph Christiano’s book Blood Type, Body Type, and You, both describe the impact of food lectins on health and chronic illness, including psychiatric illness. Food lectins cause a clumping of red blood cells inside blood vessels, which impairs oxygen delivery to tissues, and therefore tissue and brain metabolism.
A person who consumes a food that causes an imbalance in their metabolism or is sensitizing for them will have chemical reactions between lectins on their blood cells and lectins on their food. Severe food allergies can also cause inflammation in the brains of some individuals, which contributes to emotional disease.