Hot and Cold Theory: Evidence in Nutrition.

Ancient scholars across cultures have postulated that by being less potent versions of herbs, food plays a substantive role in the maintenance of health and treatment of disease. A commonality among these traditional medical systems is in relation to the 'heating' and 'cooling' properties of foods. In this chapter, 'hot' and 'cold' classifications of foods are explored, along with ways to optimize health and combat disease. Scientific evaluations of 'hot' and 'cold' properties are also reviewed in relation to chemical compositions and physiological impacts. A broad scoping Google Scholar search was conducted to identify relevant articles. Scientific evaluations were heterogeneous and of mixed quality. Nonetheless some evidence supported the traditional 'hot' and 'cold' classifications. Overall, 'heating' foods were associated with metabolism and sympathetic nervous system enhancement via increased proportions of caffeine, carbohydrate, protein, fat, and calories; as well as greater oxidation potential; vasodilatory and pro-inflammatory effects; and higher acidity and aromatic compound content. 'Cooling' foods were contrastly found to be higher in water, fiber, alkalinity, and aliphatic compounds; as well as associated with anti-inflammatory, and detoxification (elimination) processes. With the potential to specifically tailor diets to suit individual needs, further high-quality research to substantiate traditional food classifications is warranted.