Coffee is one of the most frequently consumed beverages in the world. It represents a culture and an economy. It has been produced in Colombia since the nineteenth century and is the main export to more than 36 countries; in 2008 it represented close to 12.4% of the harvest of mild Arabica type coffee and 12.2% of worldwide coffee exports. There are approximately 590 coffee growing municipalities, 513,000 coffee growers, 640,000 direct employees, and more than a million indirect employees, which means approximately 2 million people dependent on coffee cultivation [1]
Over 2,000 substances have been isolated from coffee. The major component of coffee is carbohydrates, which make up 38–42% of the toasted coffee bean, followed by lipids and amino acids with about 20 and 10%, respectively. Melanoidins make up 23% of the weight and are what give the beans their brown color. They also contain minerals, aliphatic and chlorogenic acids, trigonellines, and volatile aromas. Of the alkaloids, the most studied and recognized one is caffeine, which makes up 1.3 to 2.4% of the bean’s weight [2] followed by other purinic alkaloids such as theobromine and theophylline and pyridine such as trigonelline.
Coffee consumption is generally associated with a large number of diseases and health alterations. However, the majority of epidemiological studies regarding this relationship have not yielded a clear conclusion, mainly due to the lack of concrete and continuous information regarding the frequency of consumption, the exact composition of the beverage, and factors associated with an unhealthy lifestyle (cigarette smoking, alcohol, and sedentarism). These aspects in combination could lead to diseases or health problems [3].
Many epidemiologic studies have studied the relationship between coffee consumption and the risk of heart disease. An analysis [4] of the coffee-mortality relationship states that there is no direct relationship between coffee consumption and an increase in mortality; on the contrary, the authors describe a slightly Inverse relationship between the consumption of coffee and their benefits related to the inflammatory process, endothelial function, and the risk of developing type 2 diabetes. According to Yukawa et al. [5] the regular consumption of coffee reduced susceptibility to low-density lipoprotein oxidation, a pathway which develops in atherosclerotic plaques, thus favoring endothelial function. In another vein, it has been shown that some coffee components, especially phenolics (chlorogenic acid, ferulic acid), have a great antioxidant capacity [6], and the consumption of coffee is associated with a small reduction in mortality in women with hepatic disease and/or cirrhosis and shows a protective effect on the liver in hepatic cancer [7]. Additionally, caffeine increases the production of urine with water and electrolyte secretion patterns very similar to those seen with the thiazides [8]. The underlying mechanisms may depend on various factors such as dose, chronic exposure, genetic and enzymatic factors, among others. In animal studies with caffeine exposure, an increase in glomerular filtration and kidney blood flow, especially in the renal medulla, is seen. In a study of the intrarenal mechanisms responsible for the natriuretic effect of caffeine, the renal secretion of sodium increased, and the glomerular filtration rate remained the same, suggesting that diminished fractional sodium reabsorption, both in the proximal and distal tubule of the nephron, contributes to the natriuretic effect of caffeine [8]
Caffeine is the psychoactive substance most widely consumed in the world, it is found not only in coffee but also in tea, carbonated beverages or soft drinks, chocolate, and a wide variety of medications, including appetite suppressants, diuretics, analgesics, and decongestants; the majority of which are sold over the counter and do not have a regulatory control [9, 10]. If you combine the consumption of coffee, tea, chocolate, and soft drinks, the general population consumes a considerable amount of caffeine per day. Adults over the age of 25 have an estimated consumption of approximately 2.4 mg/kg/day, while children under the age of 12 have an estimated consumption of approximately 0.7 mg/kg/day. In addition, it has been confirmed that theobromine and theophylline are alkaloids also found naturally in green tea, black coffee, and cacao [11] however, the direct effect of these substances on physiological responses to the ingestion of foods and beverages containing these types of alkaloids, and the role of each, is not clear.