Olive (Olea europaea) is a small, evergreen tree native to the Mediterranean, where the fruit and leaf have been used as food and medicine for centuries. While the fruit yields a culinary oil that is rich in monounsaturated fats, olive leaf has demonstrated antibacterial, anti-inflammatory and antioxidant properties and may offer protection against cardiovascular and neurological diseases.
One of the primary constituents in olive leaf is oleuropein, a phenolic compound that lends the herb its bitter flavor and inhibits oxidation of low-density lipoproteins (LDL), which equates to a reduced risk of the development of arterial plaque. Oleuropein also increases inducible nitric oxide synthase (iNOS) expression and is a nitric oxide scavenger. To translate: iNOS is one of three enzymes involved in the synthesis of nitric oxide (NO) from L-arginine, which plays a key role in the regulation of blood pressure, inflammation and the ability to fight off infections. We all know what can happen with too much of a good thing -- if nitric oxide levels become elevated, tissue damage occurs and this is the trigger for the onset of disease. Other effects of oleuropein observed in studies includes anti-inflammatory effects driven by inhibiting the activity of lypoxygenases, enzymes that promote inflammatory immune system chemicals such as leukotrienes and arachidonic acid.
Another potent compound found in olive leaf is apigenin, a phenolic antioxidant also found in apples, chamomile, celery and parsley. Studies have shown that apigenin promotes apoptosis, or programmed cell death, in cancer cells. Researchers at The Ohio State University's Comprehensive Cancer Center describe this effect as making cancer cells "mortal" by eliminating their “superpower to escape death."
Historically, olive leaf and fruit have been used to counter diabetes and recent studies confirm this association. For example, a study published in the Journal of Medicinal Food resports that olive leaf compounds prevent the formation of advanced glycation end products (AGEs), substances that are responsible for the development of complications in diabetes, such as diabetic neuropathy. These rogue proteins are also involved in promoting oxidant stress and inflammation that leads to and/or complicates other degenerative diseases, including cancer, atherosclerosis and Alzheimer's disease.
Olive leaf herb can be prepared as tea, but it is more effective (and palatable) tinctured in alcohol or taken in capsule form. To make your own capsules, simply fill empty capsules with an encapsulating device. To make a 1:4 tincture (meaning 1 part herb to 4 parts alcohol), fill a sterile glass jar with a tight-fitting lid 1/4 of the way with herb and cover with the highest proof vodka you can find. Seal and let infuse for 6 to 8 weeks, gently turning the jar each day. Add more vodka, if necessary, to keep the herb covered. Strain through a fine wire mesh lined with cheesecloth, reserving the liquid and discarding the herbal material (or relegating it to the compost heap). Transfer the tincture into amber bottles with eyedroppers, label and store in a cool, dark place.
"Cardioprotective and neuroprotective roles of oleuropein in olive."; Saudi Pharmaceutical Journal; Syed Haris Omar; July 2010 http://www.sciencedirect.com/science/article/pii/S131901641000040X
"Oleuropein in Olive and its Pharmacological Effects."; Scientia Pharmaceutica; Syed Haris Omar; June 2010 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3002804/
"Inducible nitric oxide synthase--time for reappraisal."; Current Drug Targets. Inflammation and Allergy.; Lirk, P. et al.; March 2002 http://www.ncbi.nlm.nih.gov/pubmed/14561209
"Endothelial Nitric Oxide Synthase in Vascular Disease: From Marvel to Menace"; American Heart Association; Förstermann, U. et al.; 2006 http://circ.ahajournals.org/content/113/13/1708.full
"The Compound in the Mediterranean Diet that Makes Cancer Cells Mortal."; Research and Innovation Communications; May 2013 http://researchnews.osu.edu/archive/apigenin.htm
"Elucidation of mechanisms underlying the protective effects of olive leaf extract against lead-induced neurotoxicity in Wistar rats."; Seddik, L.; The Journal of Toxicological Sciences; 2011 http://www.ncbi.nlm.nih.gov/pubmed/22129743
"Olive leaf extracts are a natural source of advanced glycation end product inhibitors."; Journal of Medicinal Food; Kontogianni, VG. et al; September 2013 http://www.ncbi.nlm.nih.gov/pubmed/24044491
"Olive (Olea europaea L.) leaf extract attenuates early diabetic neuropathic pain through prevention of high glucose-induced apoptosis: in vitro and in vivo studies."; Journal of Enthnopharmacology; Kaeidi, A. et al.; June 2011 http://www.ncbi.nlm.nih.gov/pubmed/21540099
"Advanced glycation end products in foods and a practical guide to their reduction in the diet."; Journal of the American Dietetic Association; Uribarri, J. et al.; June 2010 http://www.ncbi.nlm.nih.gov/pubmed/20497781