The era of low-fat dieting has been supplanted by a new focus on healthy fats. Dietary fats give food a more pleasing texture and help your body absorb fat-soluble nutrients, like vitamins A, D, E, and K. Fat also serves as an energy source and supplies more calories per gram than the other macronutrients, specifically, protein and carbohydrates. Plus, you need a certain quantity of fat in your diet to make two essential fatty acids – linoleic acid and linolenic acid. Fat plays a vital role in hormone synthesis and brain health. In fact, a significant portion of your brain is made up of fat. So, a fat-free diet would not be conducive to health.
What are Fats?
Fats are made up of a glycerol backbone to which fatty acids are attached and fall into three classes based on their structure: polyunsaturated, monounsaturated, and saturated fats. Saturated fats are abundant in meat and dairy foods as well as coconut oil and palm oil. Polyunsaturated fats are rich in vegetable oils, nuts, seeds, as well as fatty fish and come in two varieties: omega-6 fats and omega-3 fats. Finally, monounsaturated fats are most concentrated in olive oil, avocados, macadamia nuts.
While polyunsaturated fats lower LDL-cholesterol, they’re also unstable. Due to their structure, they oxidize easily, making them prone to forming free radicals. For example, experts are concerned that heating vegetable oils to a high temperature may create a cascade of free radicals that are harmful to cells and tissues. In contrast, monounsaturated fats, like olive oil, are more stable than polyunsaturated fats but can still break down, or oxidize, over time. Studies link diets high in monounsaturated fats with a lower risk of cardiovascular disease and type 2 diabetes. The Mediterranean diet is an example of a diet high in monounsaturated fats.
One of the biggest sources of monounsaturated fats in the Mediterranean diet is olive oil. Extra-virgin olive oil is not only rich in monounsaturated fats, but it also contains substantial quantities of polyphenols, compounds with antioxidant and anti-inflammatory activity.
Are You Storing Your Olive Oil Properly?
Olive oil, because it has a high proportion of monounsaturated fats, is more stable than polyunsaturated oils, like corn oil and soybean oil. However, research shows that the monounsaturated fats in olive can oxidize during storage, especially when exposed to oxygen, light, or heat. That’s why it’s important to purchase olive oil in a dark container that blocks light and store it in a cool place. Studies show that exposing extra-virgin olive oil to even small amounts of light can trigger oxidation. Not only does oxidation change the taste of olive oil, giving it a rancid flavor, but it can also lead to the formation of chemical structures called aldehydes that are potentially harmful to your health.
Fortunately, the polyphenols in olive oil offer some protection against oxidation. However, the polyphenols in olive oil break down over time. As the polyphenols decline, olive oil oxidizes and becomes rancid. That’s not what you want.
Olive Oil Fakery is Common
Another thing that can rob you of the health benefits of olive oil is buying fake olive oil. Surprisingly, a portion of the olive oil you find on store shelves is diluted with other less healthful oils, including corn oil and soybean oil. In fact, testing carried out at the University of California at Davis found that 7 out of 10 bottles of olive oil they tested didn’t contain what it advertised. Some brands were diluted with less expensive oils such as soybean oil to create a mix of oils that have fewer health benefits. In fact, most of the oils mixed with olive oil by these companies are rich in omega-6s and are highly processed.
Interestingly, olive oil is strictly regulated in Europe and has to meet certain standards to be called extra-virgin olive oil. In the United States, olive oil makers don’t have to abide by these standards. In testing discussed by Consumer Reports, of the 23 they tested, most had deficiencies. For some, they were stored improperly so that the olive oil could easily degrade and others didn’t contain pure olive oil.
How can you be sure you’re not using fake olive oil? Sometimes you can get an idea from the taste. Authentic extra-virgin olive oil has a rich, strong taste that’s a bit overpowering. You don’t get that sharp, full-bodied taste with other oils. However, you can’t always taste olive oil before you buy it. Plus, some manufacturers add coloring and flavoring agents to mimic the real thing.
Since olive oil is more strictly regulated in Europe, buying it from an area in Italy that produces olive oil should theoretically increase the odds of getting the real thing, although one study found that 11% of bottles of olive oil from Italy were mislabeled. Some olive oils carry a certification seal that their olive oil is legitimate but even that isn’t a guarantee. Be suspicious if a bottle is too inexpensive. A good bottle of legitimate olive oil should cost ten dollars and up.
Fortunately, California recently established standards that olive oil must pass to be labeled as extra-virgin olive oil and participation upon olive oil makers is mandatory. So, buying olive oil from California that bears the California Olive Oil Council seal is another way to increase the likelihood you’re getting legitimate extra-virgin olive oil. Be aware, that once you get the oil, proper storage is essential for to prevent oxidation.
The Bottom Line
Olive oil is one of the healthiest oils to use for low-temperature cooking applications, including sautéing. Make sure what you buy is legitimate. If you’re buying the cheapest oil out there, you’re probably not getting pure, extra-virgin olive oil. Do your research. If you buy within the United States, look for the California Olive Oil Council seal to increase the chance of getting the full health benefits this flavorful oil offers.
References:
Lipids Health Dis. 2014 Oct 1;13:154. doi: 10.1186/1476-511X-13-154.
Diabetes Care. 2016 Aug;39(8):1448-57. doi: 10.2337/dc16-0513.
Consumer Reports. “Is It True that Some Olive Oil is Fake?”
Lifehacker.com. “The Most (and Least) Fake Extra Virgin Olive Oil Brands”
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If I wanted to use olive oil where the taste isn’t so strong and used light olive oil, does it still have the same health benefits?