While commonly recognized as a high-fat food (about 80-85% of the calories in olives come from fat), olives are not always appreciated for the type of fat they contain. Olives are unusual in their fat quality, because they provide almost three-quarters of their fat as oleic acid, a monounsaturated fatty acid. (In addition they provide a small amount of the essential fatty acid called linoleic acid, and a very small amount of alpha-linolenic acid, an omega-3 fatty acid.)
The high monounsaturated fat content of olives has been associated with reduced risk of cardiovascular disease. When diets low in monounsaturated fat are altered to increase the monounsaturated fat content (without becoming too high in total fat), research study participants typically experience a decrease in their blood cholesterol, LDL cholesterol, and LDL:HDL ratio. 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. 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). These changes at a cell membrane level result in decreased blood pressure.
In terms of their phytonutrient content, olives are nothing short of astounding. Few high-fat foods offer such a diverse range of antioxidant and anti-inflammatory nutrients—some of which are unique to olives themselves.