Ever since the original Air Fryer hit the market in 2010 it’s popularity has been building. There has been a particular surge in air fryer sales in the last few years, which may be related to energy and cost-savings as well as its popularity on social media (1).

A lot of people have questions about the health impact of this method of cooking, so this article will answer the most common questions related to how healthy air frying is.

How does air frying work?

An air fryer is a countertop convection oven which circulates hot air at a high speed to cook food. This is quite similar to how an ordinary convection fan oven works. However, air fryers are much smaller than ovens. They also have a proportionally more powerful fan which points down at the food along with the heating element; rather than being at the back or side like an ordinary oven.

Because air fryers can circulate hot air around food at high temperatures, food can be cooked more quickly than in a fan oven. This also simulates the crispiness of deep frying while using very little oil due to a chemical reaction called the Maillard reaction which causes food to brown at higher temperatures (2). Hence why the air fryer chips are particularly popular.

The nutritional impact of air frying

Since air frying can produce crispy and crunchy food using less oil, this can lead to less calories and fat in a meal.

Cooking foods for longer at higher temperatures and cooking with water tends to lead to greater loss of vitamins and minerals from food - particularly vitamin C and B-vitamins (3). Whereas cooking can sometimes increase the amount of nutrients available in food, like vitamin E, vitamin A and certain polyphenols (3). Cooking can also increase the digestibility of protein (4).

Although not many studies have directly looked at the impact of air frying on nutrient levels, it’s likely that this may help to protect from nutrient loss compared with cooking methods that use water or higher temperatures for longer periods of time like boiling and deep frying.

For example, convection heat which is used in both air fryers and fan ovens, has been found to preserve antioxidants like vitamin C and vitamin E in potatoes when compared with deep frying (5).

Air frying steak has also been seen to persevere more amino acids and increase digestibility as compared with deep frying (6). Similarly, air frying seems to increase the digestibility of potato compared to deep frying (7). 

Air frying and acrylamide

Acrylamide is a compound that can form in starchy foods when cooked using high heat cooking methods like frying, baking, roasting and barbecuing, toasting or grilling; especially when cooked for long periods.

Consuming acrylamide via food may be linked to cancer risk, but this risk isn’t very clear at present (8). Evidence-based organisations such as Cancer Research UK and the National Cancer Institute in the US state that there isn’t currently enough evidence to prove a clear link between acrylamide in food causing cancer in humans, and ongoing research is needed in this area (9, 10).

Some people are concerned that air frying may lead to high levels of acrylamide due to the high temperatures used and the browning/crisping of the food that occurs. However, studies have found that in comparison to deep frying, acrylamide levels were 78-90% lower in air-fried potatoes which may be due to a lower amount of oil and frying temperature (11, 12, 13). When the levels of acrylamide produced in these studies are compared to the levels that can occur from pan frying (i.e. shallow frying), air frying still appears to create significantly lower levels (14). Studies investigating the impact of deep frying versus air frying on chicken have also found that airfrying led to significantly less acrylamide (15).

Similarly, other potentially harmful substances that can be produced from high temperature cooking such as polycyclic aromatic hydrocarbons (PAHs) and advanced glycation end products (AGES) have been found to be lower in air fried foods as compared with deep frying; although not necessarily when compared to pan frying or baking (16, 17, 18). 

Safety of non-stick coating

Air fryers use non-stick coating in their baskets and trays. Polytetrafluoroethylene (PTFE) is a common material used for this, which is more widely known as Teflon.

There have been concerns linked with PFTE due to a chemical called perfluorooctanoic acid (PFOA) that may be linked with an increased risk of certain types of cancer. However, there is currently limited evidence in humans to back this up (19). Teflon used to contain PFOA but it no longer does (20).

But Teflon still contains other substances such as perfluoroakly and polyfluoroaklyl substances (PFAS) which may pose a risk to health. Research is ongoing to investigate the potential health risks of these substances from dietary exposure (19, 21).

At very high temperatures Teflon coating may break down and release gases and chemicals, but the potential toxicity of this isn’t fully understood at present (22). There have been some reports of lung damage or temporary short-lived flu-like symptoms in response to overheating Teflon above 300 degrees celsius (23, 24, 25). However, this is unlikely to be an issue at ordinary cooking temperatures.

If you are concerned about this you can opt for an air fryer that uses stainless steel or PTFE-free ceramic coating instead of Teflon; you can usually find information about this on product websites. 

So is air-frying a healthy choice?

Air frying can produce crunchy and crispy food using less oil and fat than methods like deep frying by circulating hot air around food at high speeds.

As this can use lower temperatures for shorter periods of time this may help with preserving nutrients in food and a few studies have found that it can make certain foods easier to digest as well.

Air-fried food has also been seen to contain lover levels of potentially harmful compounds like acrylamide, PAH and AGES.

There have been some concerns raised about the safety of the non-stick coating used on air fryers. But this isn’t usually an issue currently as the main chemical of concern PFOA isn’t used in Teflon coating anymore and very high temperatures are needed to break down non-stick coating. A number of air fryers also now use stainless steel or PTFE-free ceramic coating instead of Teflon.

All round, air-frying is a healthy cooking method - as well as being really quick and convenient.