Olive Leaf Usage

Olive leaf contains a substance called oleuropein, which breaks down in the body to another substance called enolinate. On websites that promote olive leaf extracts, it is stated that enolinate kills harmful bacteria, viruses, and fungi in the body, but at the same time nurtures microbes that are good for health. This remarkable claim, however, has no meaningful scientific justification.

It is true that oleuropein, enolinate, and other olive leaf constituents or their breakdown products can kill microbes in test-tube studies . ^{1 2 3 4 5 6 7 8 9 10} However, it is a long way from test-tube studies to evidence of efficacy in humans. Only double-blind , placebo-controlled studies can prove a treatment effective, and the only study of this type reported for olive leaf was too flawed to prove anything. This small, poorly designed trial supposedly found that olive leaf extract reduces blood pressure . ¹¹ However, the study was too small and too poorly designed to produce meaningful results. The only other support for the widespread claim that olive leaf reduces blood pressure comes from test-tube and animal studies that are too preliminary to rely upon at all. ^{12 13 14} Other animal studies weakly suggest that olive leaf might help control blood sugar levels in diabetes ^{15 16} and reduce symptoms of gout . ¹⁷