Coffee naturally contains a variety of compounds including caffeine, antioxidants and diterpenes. These contribute not only to the unique flavour but also to the well-researched effects of coffee on health.
Caffeine is the major pharmacologically active compound in coffee and it is a mild central nervous system stimulant. Caffeine is found in some 60 plant species of which cocoa-beans, kola nuts, tea leaves and coffee beans are the most well known, in addition caffeine is added to many popular carbonated drinks and is also a component of a number of pharmacological preparations and over-the-counter medicines. A typical cup of coffee provides approximately 80 – 100mg caffeine. Extensive research has shown beneficial effects of caffeine in the diet, such as improved attention5, alertness5 and physical performance6. In some individuals, however, there can be adverse effects, such as disturbed sleep patterns7.
Coffee naturally contains a variety of compounds that display antioxidant properties. These include chlorogenic acids and melanoidins which can deactivate oxidants, and N-methylpyridinium, which can boost cell defence mechanisms8,9,10,11.
- A number of studies have shown an increase in blood antioxidant levels after consumption of coffee12,13,14,15,16.
- Several factors (including level of roast, additives including milk or sugar, and the ratio of coffee to water) make it difficult to attribute these increases in blood antioxidant levels to specific compounds in coffee.
- Different antioxidant compounds found in coffee appear to show different effects in the body, but there is a need for further research on the bioactive and potential health-giving roles of these compounds before conclusions can be drawn.
The diterpenes, cafestol and kahweol, are both naturally present in the oil contained in coffee. Studies have shown that high consumption of these compounds can raise serum levels of total and LDL cholesterol17.
- The impact is largely related to the method of brewing since these compounds are largely retained in the paper filter in filtered coffee, but pass into the brew in Scandinavian boiled coffee, Cafètiere (plunger pot), Greek and Turkish coffee17,18.
- Soluble coffee contains virtually none of these cholesterol-raising compounds18. Moderate consumption of espresso (2-3 cups) also has negligible effects, as levels are lower than unfiltered coffee and serving sizes are smaller.
- Some studies suggest that diterpenes may also have a protective role against some cancers, including colorectal cancer19, although further research is required before any conclusions can be reached.
For more information on diterpenes and heart health, click here.
For more information on diterpenes and cancer, click here.