ABSTRACT
Brewed coffee is made by infusing roasted, ground coffee beans with hot water to produce one of the most popular beverages consumed globally. Coffee is consumed for its desirable flavour, stimulant and increasingly for its potential health benefits. Coffee beverage consumption had earlier received negative attention, since coffee tolerance was associated with being habit forming and evoking unwanted mental stimulation and mood changes, particularly when the habit of frequent consumption was abruptly stopped. Tolerance and withdrawal symptoms are linked to the antagonistic effects of the trimethylxanthine, caffeine, on adenosine receptors (Snyder, 1981). Epidemiological studies have associated coffee consumption with ischaemic heart disease and increased risk to cardiovascular disease studies (Fox, 2013; Paul, 1963). However, follow-up studies soon identified that the connection between coffee consumption and heart disease was confounded by the close association between cigarette smoking and coffee drinking habits (Paul, 1968). Several well-designed studies that followed also failed to link coffee consumption to cardiovascular diseases, although some early studies identified that daily coffee consumption which exceeded six cups of coffee a day was a possible risk to consumers (Hennekens, 1976). Especially in the last decade, scientists have worked objectively to understand the physiological and biochemical mechanism of coffee consumption in establishing recommendations for human health and wellness. This effort has been abetted with advances in meta-analysis and genomic sciences. One excellent example includes
the population-wide association of coffee consumption in both smokers and non-smokers that concluded individual coffee consumption was linked to caffeine metabolizing enzyme [CYP1A1 and CYP1A2] activities in both smokers and non-smokers (Sulem, 2011). Relative health risks of coffee consumption have been associated with genetic predisposition to various chronic diseases based on the ability to metabolize the methylxanthines (Kotsopoulos, 2007). However, coffee beans also contain numerous bioactive compounds in addition to caffeine, including diterpenes (cafestol and kahweal), polyphenols (chlorogenic and caffeic acids) and melanoidin browning pigments (high-molecular-weight pigments also referred to as a dietary fibre) (Vitaglione, 2012), which together or collectively may modulate gut function and in particular the colonic microbiome. Evidence for health benefits of coffee for this line of investigation exists with results obtained from a NIH-AARP Diet and Health Study that reported an inverse association between coffee intake and its components with colon cancer (Sinha, 2012). Coffee contains a wide range of many different components, including carbohydrates, nitrogenous compounds, lipids, vitamins, minerals, alkaloids and polyphenolics (Spiller, 1984). With this complex composition, a few compounds in particular, namely caffeine, chlorogenic acid (CGA), ferulic acid, protocatechuic acid (PCA), trigonelline, cafestol and kahweol, have been identified to possess a variety of distinct biological activities that could impact human health and welfare. This chapter describes the contribution of some of these major bioactive compounds, both naturally present and derived from roasting coffee, with emphasis on antioxidant status, and anti-inflammatory and antimicrobial activities.
