The 6 best and worst cooking oils for your health

When it comes to cooking at home, there are numerous options for the type of oil you can use for sautéing, baking, and frying. While some oils, such as olive oil, are well-known, others, like avocado or coconut oil, may be less familiar.

So how do you choose the right cooking oil? 

One crucial factor to consider is an oil's smoke point, which is the temperature at which it begins to burn and release smoke. Heating an oil beyond its smoke point can negatively affect its taste and composition, leading to the release of harmful compounds called free radicals.

Olive oil

Contrary to the myth that frying in olive oil is not recommended, it is actually the most suitable vegetable oil for frying. This is due to its high content of oleic acid, a fatty acid that is highly resistant to heat.

Quality olive oil also has a high smoke point and is rich in antioxidants, making it ideal for deep frying. The lower the acidity level of olive oil, the higher its smoke point and stability.

The smoking temperature of olive oil exceeds 200 degrees Celsius, while at-home deep frying typically reaches about 170-180 degrees Celsius. In contrast, oils like soybean, corn, and sunflower are highly sensitive to decomposition and become unstable at high temperatures.

Additionally, olive oil's high content of natural antioxidants like polyphenols and tocopherols aids in disease prevention and maintains fatty acid stability during frying. Even after several frying cycles, the natural antioxidants in olive oil help protect the fatty acids from oxidation.

Coconut oil

Coconut oil remains a controversial topic, even among the scientific community. It contains a significant amount of saturated fats, which are deemed the most harmful among all fats. Consuming saturated fats is associated with increased cholesterol levels and a heightened risk of cardiovascular diseases. 

Studies comparing the effects of coconut oil and olive oil consumption found that coconut oil increased LDL (low-density lipoprotein, a bad cholesterol) levels similar to other saturated fats like butter, beef fat, and palm oil. Therefore, it is advisable to limit coconut oil intake.

Moreover, coconut oil has a relatively low smoke point of 171 degrees Celsius, making it unsuitable for deep frying. Proportional consumption is recommended, as excessive hype around coconut products lacks scientific backing.

What is vegetable oil?

The term "vegetable oil" is commonly found on ingredient lists of various products. It refers to any oil derived from plant sources, with its healthiness depending on the source. Most vegetable oils available are mixtures of canola, corn, soybean, safflower, palm, and sunflower oil.

These refined and processed oils tend to have an unhealthy fatty acid composition. The negative impact of processed foods on health is well-documented, and the same applies to these oils.

Canola oil

Canola oil, extracted from rapeseed, is a source of plant-based omega-3 fatty acids that are essential for the body as it cannot produce them on its own. It also contains a relatively high amount of monounsaturated fat, providing an alternative for those who dislike olive oil's distinct taste.

However, due to the extraction process involving heating, solvents, and refining, canola oil is not considered a healthy choice.

Avocado oil

Avocado oil, with its high smoke point, is an excellent option for higher heat cooking and sautéing. It has a mild flavor similar to avocados, making it ideal for cooking purposes. Avocado oil is rich in monounsaturated and polyunsaturated fatty acids, and it contains vitamin E. The downside is its higher cost.

These oils, apart from being processed, have a high content of omega-6 fatty acids, which are considered pro-inflammatory compared to the anti-inflammatory omega-3 fatty acids. Consuming a high ratio of omega-6 to omega-3 in one's diet may increase inflammation in the body, making these oils less desirable.

Flaxseed oil

Flaxseed oil is a valuable source of omega-3 fatty acids but has a very low smoke point, rendering it unsuitable for cooking. It should be stored in a cool place, preferably in the refrigerator.

So what should you buy?

In conclusion, extra virgin olive oil with low acidity, stored in dark bottles and proper conditions, is the recommended main oil for use in salads, cooking, and frying.

Regarding frying at home, where the oil is discarded after use and not reused like in restaurants or falafel shops, it poses no harm to health. The principles of the Mediterranean diet, also endorsed by the Israeli Health Ministry, emphasize the consumption of olive oil and other healthy fats like those found in almonds, walnuts, seeds, and avocados. These fats contribute to maintaining heart health and reducing cholesterol levels.

Einat Mazor Becker is a clinical dietitian at the DMC Diabetes Center.