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| Article & Photo by Ann Walker |
Olive tree leaves have long been used in the Mediterranean region as traditional medicine. The leaves contain higher amounts of polyphenols (healthful plant chemicals) than even extra virgin olive oil or the olives themselves. Clinical and laboratory evidence already supports the cardio-protective, anti-oxidant and anti-inflammatory properties of these compounds, which are thought to confer the health-giving properties to olive oil. More recently, research attention has turned to the immune-supporting properties of olive leaf. In one study, white cells were taken from blood samples of 25 healthy volunteers and cultured in the laboratory with extracts of olive leaf. The extracts favourably modified the immune biochemicals from these cells (compounds such as interferon and cytokines) so as to support the notion of olive leaf as potential treatment for infections and chronic inflammatory diseases. PMID: 29149822
This hypothesis was put to the test in a two-month, double-blind, randomized controlled trial in New Zealand on young elite athletes (PMID: 30744092). In this study, olive leaf extract was used to study the incidence and duration of colds to which athletes are particularly prone. The intervention group received extract tablets equivalent to 20 g per day of olive leaf. Whilst there was no difference in the incidence of colds between the active and control groups, there were 28% fewer sick days in the olive leaf group. This was because the average duration of illnesses was 9.7 days in the olive leaf group compared to 12.3 days in the placebo group.
It is good to see evidence coming through for herbal remedies to combat upper respiratory viral infections, even though the study in this case was small (29 people completed the study). There is little that modern medicine can offer against these common viruses that we all suffer – or indeed, viral infections in general. Other natural remedies studied in clinical trials showing benefit for common viral infections include pelargonium and andrographis, but results of trials are equivocal for vitamin C and echinacea, despite their popular use by the public and herbal practitioners. New angles like this on olive leaf provide further natural solutions for viral infections and are always very welcome.
PMID = PubMed identifier
Ann Walker PhD, FCPP, MNIMH, RNutr
Course Director DHM
Herbal Practitioner
