The Healthiest Oil for Deep Frying
Deep-fried foods play a role in many traditional cuisines and are a staple of the fast food industry.
However, deep-fried foods can have a negative effect on health.
This will depend partly on how often you eat it, but also on the type of oil you use and how you use it.
Deep frying involves cooking food by submerging it in hot oil.
The ideal temperature is around 350–375°F (176–190°C).
Submerge a food in oil at this temperature causes its surface to cook almost instantly. As it cooks, it forms a type of seal that the oil cannot penetrate.
At the same time, the moisture inside the food turns into steam, cooking the food from the inside. The steam also helps keep the oil out of the food.
However, you have to have the right temperature:
SUMMARYDeep frying involves submerging food in hot oil. At the right temperature, this will instantly cook the surface and trap the moisture inside the food.
Some oils can withstand higher temperatures than others.
A healthy oil for cooking will:
Oils that contain higher levels of saturated fats tend to be more stable when heated.
Oils that are mostly saturated and monounsaturated are good for frying.
However, cooking oils that contain large amounts of polyunsaturated fats are less suitable for frying (1).
This is because polyunsaturated fats contain two or more double bonds in their chemical structure. These double bonds can react with oxygen and form harmful compounds when exposed to high heat.
Taste is also important. When deep frying, oils with a neutral flavor are usually preferable.
SUMMARYOils that consist mostly of saturated and monounsaturated fats are best for deep frying because they’re the most stable at high heat.
Coconut oil may be a good choice.
Studies have shown that even after 8 hours of continuous deep frying at 365°F (180°C), its quality still remains acceptable (2Trusted Source).
Over 90% of the fatty acids in coconut oil are saturated, making it resistant to heat.
Experts don’t agree on the benefits and drawbacks of using saturated fats.
Mainstream organizations, such as the American Heart Association, recommend limiting intake of saturated fats to 5–6% of total calories. However, various studies have concluded that saturated fats don’t increase the risk of heart disease (3Trusted Source, 4, 5).
Coconut oil may have various other health benefits. One study suggests that it may help you lose belly fat (6Trusted Source).
When choosing coconut oil, bear in mind that some varieties can leave a flavor or smell that not everyone enjoys. It’s best to try a few brands until you find one that’s suitable.
SUMMARYCoconut oil is high in saturated fats and doesn’t appear to change quality during deep frying. A range of possible health benefits may make coconut oil a good choice for frying.
Animal fats, such as lard, tallow, ghee, and fat drippings, can be excellent choices for deep frying.
Most fatty acids in animal fats are saturated and monounsaturated. This makes them resistant to high heat.
However, the fatty acid content can vary, depending on the animal's diet (7Trusted Source, 8, 9Trusted Source).
Grain-fed animals may have more polyunsaturated fatty acids in their fat stores than pasture-raised or grass-fed animals.
The best choice, therefore, comes from animals that have been allowed to roam and eat naturally.
Butter is unsuitable for deep frying. It contains small amounts of carbs and protein that burn when heated. Clarified butter and ghee are better options.
SUMMARYAnimal fats consist mainly of saturated and monounsaturated fats, making them suitable for cooking at high temperatures.
There are several other good options.
Olive oil is one of the healthiest fats.
It’s resistant to heat because, like animal fats, it’s high in monounsaturated fatty acids. These have only one double bond, making them relatively stable.
In one study, researchers used olive oil in a deep fryer for over 24 hours before it oxidized excessively (10Trusted Source).
In theory, this makes it a great choice for deep frying.
However, the flavor and fragrance of olive oil may deteriorate when heated for a long time.
Avocado oil has a similar composition to olive oil. It’s mainly monounsaturated with some saturated and polyunsaturated fats mixed in.
Refined avocado oil has a high smoke point of 520°F (270°C) and a slightly nutty taste.
Peanut oil, also known as groundnut oil, has a high smoke point of about 446°F (230°C).
It’s popular for deep frying because it has a neutral taste (11).
However, it may not be as healthy as some other choices.
It contains around 32% polyunsaturated fats. This is a relatively high amount that makes it vulnerable to oxidative damage at high temperatures (12Trusted Source).
Palm oil consists mostly of saturated and monounsaturated fats, making it a great choice for deep frying.
The flavor can be neutral, particularly if you use the unrefined variety known as red palm oil.
However, some people have concerns about the sustainability of cultivating and harvesting palm oil.
SUMMARYOlive oil and avocado oil are good choices for deep frying. Peanut and palm oils are less suitable, either for health or environmental reasons.
Some fats and oils aren’t suitable for deep frying.
They include vegetable oils that are high in polyunsaturated fatty acids, such as:
Using these oils for deep frying can result in large amounts of oxidized fatty acids and harmful compounds (13).
SUMMARYVegetable oils that are high in polyunsaturated fatty acids are unsuitable for deep frying. They are less heat-resistant than oils or fats that are high in saturated or monounsaturated fatty acids.
Even if you use healthy oil, deep frying will add a lot of calories to food, so it’s best not to eat it too often.
The extra calories typically come from coatings, including batter and flour, plus the oil that sticks to the food after cooking.
A high consumptions of deep-fried foods is linked to weight gain, especially in people with a family history of obesity (16Trusted Source).
To minimize the extra calories, be sure to cook the food:
Deep-fried food doesn’t have a reputation for being healthy. Eating too much of it cooked in the wrong oils can lead to health problems.
However, in moderation, deep frying with the right oils can make a tasty treat.
Here, you can find more information about which oils to use in cooking.