The oleic acid found in olives—once absorbed up into the body and transported to our cells—can change signaling patterns at a cell membrane level (specifically, altering G-protein associated cascades).
Because histamine is a molecule that can get overproduced in allergy-related conditions and can be a key player in the inflammatory process, it's likely that the anti-inflammatory benefits we get from olives involve this anti-histamine pathway.
All of these changes lower our risk of heart disease.
Recent research studies have also shown that the monounsaturated fat found in olives (and olive oil) can help to decrease blood pressure.
Additional information about the amount of these nutrients provided by Olives can be found in the Food Rating System Chart.
A link that takes you to the In-Depth Nutritional Profile for Olives, featuring information over 80 nutrients, can be found under the Food Rating System Chart.In the United States, where most olives come from California, olives are typically green in color, picked in an unripe state, lye-cured, and then exposed to air as a way of triggering oxidation and conversion to a black outer color.