Frederick T. Travis1 and Robert Keith Wallace2
INTRODUCTION
Typologies have been delineated for body structure (ectomorph, mesomorph, and endomorph),[1] mental functioning (multiple intelligences),[2,3] emotional response (levels of emotional reactivity or sensation- seeking), social relationships (level of need for attachment), and behavioral tendencies (level of stress reactivity). Ayurveda, the traditional medical system of India, has delineated three categories of fundamental regulatory principles of the body, mind, and behavior. These three categories, called doshas, are named Vata, Pitta, and Kapha.[4] The category of Vata dosha includes processes responsible for cell division and cell signaling, movement at all levels of the physiology, excretion of wastes, and also cognition. Vata also regulates the activities of Kapha and Pitta. The category of Kapha dosha includes processes responsible for anabolism, growth and maintenance of structure, storage and stability. The category of Pitta dosha includes processes responsible for metabolism, thermo-regulation, energy homeostasis, pigmentation, vision, and attentional processes.[5] The physical, mental, and behavioral characteristic of each dosha are summarized in Table 1. Notice that the descriptions listed are primarily based on external observation of physiological characteristics and behavior [Table 1].
PHYSIOLOGICAL PATTERNS SUPPORT THE TRIDOSHIC THEORY
A body of research has grown, which explores patterns of blood chemistry, genetic expression, physiological states, and chronic diseases associated with each dosha type.[6] Triglycerides, total cholesterol, high low-density lipoprotein (LDL), and low high-DL (HDL) concentrations-all common risk factors for cardiovascular disease were reported to be higher in Kapha types compared to Pitta and Vata types. Hemoglobin and red blood count were higher in Pitta compared to other types. Serum prolactin was higher in Vata types.[5] Other research supports these findings that high levels of triglyceride, very LDL and LDL levels and lower levels of HDL cholesterol distinguish Kapha types from other types.[7]
Genetic expression also distinguishes dosha types. Genes in the immune response pathways were up-regulated in Pitta types, genes related to cell cycles were up-regulated in Vata types, and genes in the immune signaling pathways were up-regulated in Kapha types.[5] Inflammatory genes were up-regulated in Vata types, whereas up-regulation of oxidative stress pathway genes were observed in Pitta and Kapha types.[8] CD25 (activated B cells) and CD56 (natural killer cells) were higher in Kapha dosha types. CYP2C19 genotypes, a family of genes that help in detoxification and metabolism of certain drugs were down-regulated in Kapha types and up-regulated in Pitta types.[9,10]
Physiological patterns also distinguish dosha type. Adenosine diphosphate-induced maximal platelet aggregation was the highest among Vata/Pitta types.[11] In diabetic patients, there were significant decreases in systolic blood pressure in Vata/Pitta, Pitta/Kapha, and Vata/Kapha types after walking (isotonic exercise). The Vata/Pitta types also showed significant decreases in mean diastolic blood pressure.[12] In terms of biochemistry, Kaphas had elevated digoxin levels, increased free radical production and reduced scavenging, increased tryptophan catabolites and reduced tyrosine catabolites, increased glycoconjugate levels, and increased cholesterol: Phospholipid ratio of red blood cell membranes. Pittas showed the opposite biochemical patterns. Vatas showed normal biochemical patterns.[13]
A study of basic cardiovascular responses reported that heart rate variability and arterial blood pressure during specific postural changes, exercise, and cold pressor test did not vary with constitutional type.[14] A more recent paper measuring cold pressor test, standing-to-lying ratio, and pupillary responses in light and dark reported that Kapha types have higher parasympathetic activity and lower sympathetic activity in terms of cardiovascular reactivity as compared to Pitta or Vata types.[15]
An open question in this discussion is how these genetic, metabolic, and physiological factors express themselves in terms of more expressed lifestyle and behavioral characteristics. Obviously, many genetic and metabolic factors are influenced by the nervous system, which not only controls metabolic and growth factors through the endocrine system but have an impact on the functioning of the immune, digestive, cardiovascular, and virtually every other system in the body. Further, it controls all our mental, emotional, and behavioral systems including attention, learning, memory, and sleep.
THEORY OF DOSHA BRAIN-TYPES
Brain functioning underlies and affects mental and behavior functioning. Thus, the dosha types which are based on observable mental and physical behavior and characteristics, should also be based on different patterns of brain and nervous system functioning. Thus, defining fundamental brain types may give a means to understand individual differences.
For instance, Vata dosha, which is highly variable in behavior and in response to the environment, would be associated with a greater range of functioning of the brain and nervous system. Pitta dosha, which is characterized by dynamism, would be associated with fast, passionate responses of the brain and nervous system to challenges in the environment. Kapha dosha, which is characterized by steadiness, would be associated with stabile activity patterns of the brain and nervous system.
These three different types of brain functioning can be seen as different patterns of functioning of six major systems of the nervous system. Table 2 presents an overview of this model.
