Over 1,000 chemicals have been reported in roasted coffee; more than half of those tested (19/28) are rodent carcinogens. Coffee also contains healthful chemicals, including polyphenols (chlorogenic acid and caffeic acid), as well as diterpenes (kahweol and cafestol).Caffeine
The world's primary source of caffeine is the coffee bean (the seed of the coffee plant), from which coffee is brewed. Caffeine content in coffee varies widely depending on the type of coffee bean and the method of preparation used; even beans within a given bush can show variations in concentration. In general, one serving of coffee ranges from 40 milligrams, for a single shot (30 milliliters) of arabica-variety espresso, to about 100 milligrams for a cup (120 milliliters) of drip coffee. Generally, dark-roast coffee has less caffeine than lighter roasts because the roasting process reduces the bean's caffeine content. Arabica coffee normally contains less caffeine than the robusta variety.Coffee also contains trace amounts of theophylline, but no theobromine.
Caffeine is a stimulant drug. It is a xanthine alkaloid compound that acts as a psychoactive stimulant and diuretic in humans. The word comes from the French term for coffee, café. Caffeine is also called guaranine when found in guarana, mateine when found in mate, and theine when found in tea; all of these names are synonyms for the same chemical compound.
Cafestol
Cafestol is a diterpene molecule present in coffee.A typical bean of Coffea arabica contains about 0.6% cafestol by weight. Cafestol is present in highest quantity in unfiltered coffee drinks such as French press coffee or Turkish coffee. In filtered coffee drinks such as drip brewed coffee, it is present in only negligible amounts.Studies have shown that regular consumption of boiled coffee increases serum cholesterol by 8% in men and 10% in women. For those drinking filter coffee, the effect was only significant for women.Cafestol has also shown anticarcinogenic properties in rats.According to a 2005 study by the Baylor College of Medicine, cafestol may act as an agonist ligand for the genes FXR and PXR, blocking cholesterol homeostasis.
Caffeic acid
Caffeic acid is a naturally occurring organic compound. This yellow solid consists of both phenolic and acrylic functional groups. It is found in all plants because it is a key intermediate in the biosynthesis of lignin, one of the principal sources of biomass.Caffeic acid is an antioxidant and it can also act as a carcinogenic inhibitor.
Caffeic acid is found in coffee beans. The levels of antioxidants found in caffeic acid are in line with those found in fruits, nuts, oils and other healthy foods. Moderate daily doses of coffee and caffeic acid typically can be a healthy choice.
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