The study, which is published in the Annals of Botany, reveals that coffee (Coffea) leaves contain high levels of potentially beneficial phenolic compounds including mangiferin and hydroxycinnamic acid esters (HCEs).
Led by researchers from the Royal Botanic Gardens at Kew, UK and the French Research Institute for Development (IRD) in Montpellier, the team analysed the phenolic content of 23 types of Coffea leaf, finding that they contain several beneficial compounds that are not present in traditionally drank teas or coffees. In addition the team, led by Dr Claudine Campa from IRD, confirmed that coffee leaves possess far higher quantities of antioxidant compounds than are present in green of black tea.
“The potential health benefits of coffee-leaf ‘tea’, and beverages and masticatory products made from the fleshy parts of Coffea fruit, are supported by our findings on the basis of high accumulation of phenolic compounds in coffee leaves,” said the researchers. However they noted that the accumulated influence of these compounds in the human body “would require further research.”
The team, headed up by Dr Arron Davies at Kew (pictured), noted that the leaves and outer fruit of Coffea (in particular C. arabica and C. canephora) have traditionally been used to produce tea and coffee-like beverages in areas of Asia and Africa.
There have also been historic attempts to make coffee-leaf tea as popular as black tea in the UK and Australia – it was even displayed at the Great Exhibition of 1851 – but as the researchers note, the drink did not garner enough attention to ‘catch on’.
Campa and her colleagues said the identification of Mangiferin (which was originally isolated in mangos) in leaves of Coffea is promising since the compound “is known to be anti-inflammatory, antidiabetic, antihyperlipidaemic … and also shows neuroprotective properties.”
“We have demonstrated mangiferin accumulation in seven African Coffea taxa: C. anthonyi, C. arabica, C. eugenioides, C. heterocalyx cf., C. pseudozanguebariae, C. salvatrix and C. sessiliflora,” said the authors.
“Previously the presence of mangiferin had only been detected in a single species.”
The research team also found that the main phenolic compound in tea produced from the Coffea leaf is 5-CQA, just like in green tea and green coffee beans. However the team noted that in certain Coffea species levels of 5-CQA are “considerably exceeded by mangiferin.”
Davies and Campa noted that further careful assessment of coffee-leaf tea would be required before it could be available shops or coffee chains. However they noted enticing reports from over 100 years ago, which claim coffee leaf tea offers “immediate relief from hunger and fatigue and the ability of ‘clearing the brain of its cobwebs.”
Source: Annals of Botany
Published online ahead of print, doi: 10.1093/aob/mcs119
“A survey of mangiferin and hydroxycinnamic acid ester accumulation in coffee (Coffea) leaves: biological implications and uses”
Authors: Claudine Campa, Laurence Mondolot, Arsene Rakotondravao, Luc P. R. Bidel et al