Is it safe to fry with olive oil and consume the oil?

From the Guidelines

Frying with olive oil and consuming it is generally safe and can be part of a healthy diet, as long as it is done in moderation and with proper handling, as suggested by the American Heart Association's guidelines on the Mediterranean diet 1. When using olive oil for frying, it's essential to consider the type of olive oil and its smoke point. Extra virgin olive oil is best for low to medium-heat cooking (up to about 375°F/190°C), while refined olive oil can handle slightly higher temperatures. Some key points to keep in mind when frying with olive oil include:

• Avoid heating olive oil to its smoke point (around 410°F/210°C for extra virgin olive oil) as this can create harmful compounds and degrade the oil's beneficial properties.
• Store olive oil in a cool, dark place, use within 6 months of opening, and avoid reusing oil multiple times for frying as this can lead to oxidation and formation of unhealthy compounds.
• If you notice your oil smoking during cooking, lower the heat immediately or consider using a different oil with a higher smoke point for very high-temperature cooking methods. The American Cancer Society also notes that consumption of olive oil is associated with a reduced risk of cardiovascular disease and is not associated with any increased risk of cancer, making it a healthy alternative to other oils 1. Overall, olive oil can be a healthy and safe choice for frying when used properly, and its benefits can be part of a balanced diet that includes a variety of foods, as outlined in the Mediterranean diet guidelines 1.

From the Research

Safety of Frying with Olive Oil

• Frying with olive oil is a common practice, especially in the Mediterranean area, where it is a key component of the Mediterranean diet 2.
• Olive oil has a unique lipid profile and minor components that make it a desirable choice for frying 2.
• Scientific evidence suggests that olive oil behaves equally or superior to refined vegetable oils during frying 2.

Compositional Changes in Fried Foods

• The compositional changes of foods fried in olive oil have been reviewed and discussed in detail 2.
• Frying can lead to the formation of polar compounds, such as polymers, dimers, free fatty acids, and acrylamide, which can alter metabolism and cause cancer 3.
• The transfer of mass and heat during frying can help understand the mechanism of oil absorption in fried food 3.

Oil Discarding and Toxicity

• The debate on deep-fat frying is focused on the point at which any oil used for frying should be discarded 4.
• Polar content (PC) and triacylglycerol oligomer content (TOC) determinations are used to assess oil discarding, with some countries setting a maximum level of 25% PC and 10% TOC 4.
• The relationship between PC and TOC has been studied, suggesting that TOC may give more precise information about the alteration of the oil and its potential toxicity 4.

Formation of Trans Fatty Acids

• Heating and reheating of fats and oils can induce chemical changes, including the formation of trans fatty acids (TFAs) 5.
• Olive oil, like other fats and oils, can form TFAs when heated or reheated, with an increase in TFAs and saturated fatty acids, and a decrease in cis-unsaturated fatty acids 5.

Health Benefits of Olive Oil

• Olive oil has a wide range of therapeutic and culinary applications, and is a major component of the Mediterranean diet 6.
• The active components of olive oil, including oleic acid, phenolic constituents, and squalene, have demonstrated antioxidant activity and potential health benefits, including cancer prevention and reduction of coronary heart disease risk 6.