Monounsaturated Fat

foods high in monounsaturated fats
Foods high in monounsaturated fats. Clive Champion/Photolibrary/Getty Images

Definition: What "saturated" fat molecules are saturated with is hydrogen atoms. "Unsaturated" fats do not have hydrogen atoms at every available bonding site on the molecule (this is also called a "double bond").  Monounsaturated fats have one ("mono") of these bonds which lack hydrogen. Monounsaturated fats are usually liquid at room temperature, but can turn solid in the refrigerator.

Monounsaturated fats are commonly thought of as "healthy" fats.

There is evidence that they may lower our risk of heart disease and stroke. Olive oil is most commonly associated with this type of fat, as 75% of its fat is monounsaturated.

Also Known As: MUFAs, oleic acid (which is one type of monounsaturated fat), monounsaturated fatty acids

Sources of Monounsaturated Fats: Besides olive oil, of which 77% of the fats are monounsaturated, excellent sources include macadamia nuts (80% of fat is monounsaturated), hazelnuts (77%), avocados (71%), almonds (70%), canola oil (59%), pecans (59%) and peanuts and peanut oil (46%). Also, while regular sunflower and safflower oils are not good sources of monounsaturated fat, recently some of the seeds have been bred to produce more of this type of oil. These oils are usually labeled "high oleic" sunflower or safflower oil, and can contain up to 81% monounsaturated fat.

Almost all sources of fats are a mixture of saturated, monounsaturated, and polyunsaturated fats.

For example, almost half of the fat in beef is also monounsaturated (the rest is saturated).

Benefits of Monounsaturated Fats

It is thought that at least some of the benefits of the heart-protective Mediterranean Diet are due to the high consumption of olive oil and its monounsaturated fat. There is some evidence for the following protective benefits of this fat:

1. Fats are satiating. In one study of the Mediterranean Diet, participants who added olive oil or nuts to their diets spontaneously cut down on other sources of calories.  In another study, shakes which were high in fats produced lower hunger levels than shakes with the same calories but more sugar and less fat.

2.Lower LDL cholesterol levels - The American Heart Association recommends olive oil and other sources of monounsaturated fats to help keep blood cholesterol at a healthy level.

3. Reduced risk for heart disease and stroke - This is the reason the Mediterranean Diet first came to the attention of heart disease experts.

4. Possibly reduced risk of breast cancer - There is some evidence that women with more monounsaturated fats in their bodies have a lower risk for breast cancer than women who consume less monounsaturated fat and more omega-6 polyunsaturated fat.


USDA National Nutrient Database for Standard Reference, Release 20.

Wolk, A, Bergstrom, R, et al. A Prospective Study of Association of Monounsaturated Fat and Other Types of Fat With Risk of Breast Cancer. Archives of Internal Medicine. 1998;158(1):41-45.

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