I asked experts what the ‘healthiest’ cooking oil is

Choosing a cooking oil in the supermarket can feel like a minefield. There are a plethora of options available from olive oil to avocado oil, coconut oil, sunflower oil, and more. However, not all cooking oils are made equal; some are healthier than others. This year, I’m determined to make healthier choices, and one way I want to do that is by cooking with healthy fats. I don’t fry food very often, but I am fond of roasting potatoes and slathering a good-quality slice of sourdough with extra virgin olive oil.

When I fry or roast food, my two go-to oils are olive oil and rapeseed oil. I’ve often chosen olive oil because I thought it was the healthiest option, while rapeseed oil is cheaper and is apparently low in saturated fats. Determined to make healthier choices and be more informed about my eating habits, I asked several experts which cooking oil is, in fact, the “healthiest”.

While many cooking oils were mentioned, one oil stood out: extra-virgin olive oil (EVOO), with avocado oil as a good alternative for high-heat cooking.

Despite what many people think, EVOO can be used for everyday cooking; it’s not just for salads and dips.

Erin Viljoen, a Nutritional Therapist at W-Wellness, explained that despite common myths, “cold-pressed extra-virgin olive oil is suitable for most everyday cooking, as well as dressings and finishing dishes”.

Aliza Marogy, a registered nutritional therapist and founder of leading clinical-grade supplements provider Inessa, agreed, stating that olive oil used to have a reputation for turning “toxic” upon heating, which is why it was seen as unsuitable for cooking. However, that’s certainly not the case. She added: “It is a great option for sautéeing, roasting, and pan frying, and is the oil I reach for at home for the majority of my cooking.”

Meanwhile, dietitian Dr Sarah Schenker said EVOO is “quite stable at most cooking temperatures,” but that avocado oil should be used for high-heat cooking and has a “similar fat profile to EVOO” and even contains more vitamin E.

Many of the experts consistently recommended EVOO because it contains a higher proportion of monounsaturates, which are great for your heart, brain and gut, and have a higher amount of polyphenols.

Dr Schenker added: “Overall, extra virgin olive oil is the healthiest choice because of the higher proportion of monounsaturates (good for heart health, anti-inflammatory, good for brain and gut health, improves insulin sensitivity) which are more stable when heated and less prone to oxidation – oxidation produces harmful reactive chemicals that can cause inflammation. As it’s extra virgin, it’s not refined, so it has a significantly higher amount of polyphenols (antioxidants), in particular oleocanthal and oleacein that otherwise would be lost in the refining process.”

Mazen Assaf, a certified olive oil sommelier who is also known as The Olive Oil Guy, said extra virgin olive oil is “by far the healthiest” because it isn’t chemically refined, making it essentially a “fresh fruit juice”.

Olives are fruits that grow on trees, and when they’re harvested and cold-pressed, the oil is extracted mechanically, without heat or solvents. “True extra virgin olive oil is made purely from the olive itself, which preserves its natural nutrients,” he explains.

From a health perspective, what sets extra virgin olive oil apart is its high polyphenol content. “Polyphenols are powerful antioxidants that help reduce oxidative stress and inflammation in the body, both of which are linked to chronic disease,” he says. Early-harvest olive oils, which tend to be greener and more bitter, are particularly rich in these compounds.

In contrast, refined oils, including refined olive oil and many seed oils, are heavily processed using high heat and chemical solvents, which strip away beneficial compounds and can leave behind unstable fats. “These oils may be cheaper and more neutral in flavour, but they don’t offer the same protective health benefits,” he notes.

Not all olive oils on supermarket shelves are equal, either. “Many are blended, over-refined, or poorly stored, which drastically reduces their nutritional value,” he adds. “The real health benefits come from fresh, early-harvest, cold-pressed, single-origin extra virgin olive oil.”

Tom Redwood, the founder of Good Phats, echoed this sentiment, saying the “biggest mistake people make is ignoring how the oil is processed and how it’s used”. He said: “Many modern seed oils are heavily processed using industrial methods, sometimes involving petroleum-derived solvents. By contrast, oils like extra virgin olive oil and avocado oil are naturally stable, and traditional fats such as organic British grass-fed beef tallow and organic British grass-fed beef tallow are rising in popularity because they’re more natural, heat-stable, nutrient-dense, and genuinely improve home-cooked food.”

Ms Marogy agreed that EVOO is the healthiest option, stating that it’s packed with heart-healthy fats, including oleic acid, which can help improve cholesterol levels, reduce inflammation and lower the risk of heart disease.

She added: “It also contains antioxidants and polyphenols, which protect cells from day-to-day stressors and damage. Always choose ‘extra virgin’ as it’s the highest quality grade of olive oil and ensures the flavour and nutrients, including Vitamin E, are intact.”

Ms Viljoen said EVOO is the “best all-round option”, especially when it’s cold-pressed. She explained: “Cold pressing preserves the oil’s natural polyphenols, antioxidants and vitamin E, which give olive oil its anti-inflammatory and heart-protective benefits. These compounds also help stabilise the oil during cooking.”

Meanwhile, Dr Lucy Williamson, a registered nutritionist and gut health expert, explained why choosing the best cooking oil isn’t just about which ones are the healthiest, it’s also to do with knowing which ones are ‘heat stable’ at higher temperatures when they’re used in frying and roasting and knowing how the fats change. She explains: “High temperature can cause some fats to degrade; a process called ‘oxidation’. This impacts their ‘healthfulness’ or worse, results in toxins called ‘free radicals’ being produced. Free radicals can damage our body cells.”

EVOO is a good option because it’s both heat-stable and rich in antioxidants. “These therefore help to reduce oxidation damage from high temperature cooking, even though it has quite a low ‘smoke point’ (190°C -200°C),” she adds.

However, Dr Williamson warned that some oils are refined to increase their smoke point for high-heat cooking and to prolong their shelf life. She said: “This process strips much of their natural goodness, including antioxidants and vitamin E. High-heat refining can also damage some double bonds and, in rare cases, create small amounts of trans fats, which are linked to poor health outcomes, though these are now largely eliminated from foods in the UK.”

Longevity expert Leslie Kenny, founder and CEO of Oxford Healthspan, a nutraceutical company based on Oxford research into healthy ageing compounds, said that, from a health perspective, the healthiest cooking oils are those that are chemically stable and minimally processed.

She explained: “Extra-virgin olive oil and avocado oil are excellent choices because they’re predominantly monounsaturated, resistant to oxidation, and rich in bioactive compounds that support cardiovascular and gut health.

“Many widely used industrial seed oils, such as sunflower, corn, rapeseed (canola) and grapeseed oil, are high in omega-6 polyunsaturated fats. While omega-6 fats are not inherently harmful, modern diets contain them in excessive amounts, particularly through ultra-processed foods and ready meals. These oils are also often refined at high temperatures, which can make them more prone to oxidation, which is inflammatory.

“Research published in Gut has shown associations between high intake of omega-6-rich fats and changes in gut biology linked to inflammation and increased colorectal cancer risk. Reducing reliance on these oils and switching to stable fats like olive oil is a practical, evidence-based step people can take to improve their long-term health.”

Natalie Mackenzie, a brain and cognition expert, said the “winners” are those with plant-based ALAs. She recommended olive oil as it is packed with antioxidants and monounsaturated fats that “reduce inflammation and oxidative stress”. However, she said it needs to be high-quality extra virgin olive oil that is refined and cold-pressed.

She added: “Those with high-polyphonic, which is the magic bit that reduces neuroinflammation and protects from oxidative stress. Always the most expensive, but for good reason. Look for dark glass bottles or tins, extra virgin cold pressed from one country (rather than a blend).”

Deborah Grayson, an internationally renowned pharmacist and qualified nutritional therapist who runs Practice With Confidence, offering mentoring and support to nutritional practitioners, said olive oil is “one of the healthiest” options, but there is debate around whether you should cook with it or whether heat can damage the fatty acids in the oil and remove some of its benefits.

She continued: “The real answer lies in the smoke point, which is the point at which the oil starts to produce a visible white smoke – if this happens, the temperature is too high and needs to be lowered.

“The smoke point depends on the quality of the oil and can vary between 190-210°C for extra virgin olive oil. More refined, lower-quality olive oil is stable at temperatures as high as 240°C.

“I tend to recommend sticking to 200°C as a general rule, as that suits most grades of olive oil.”

Why is avocado oil best for high-heat cooking?

According to Ms Marogy, avocado oil is a good alternative to EVOO because it is mostly made up of monounsaturated fats, which moderate inflammation and improve heart health, and refined versions can withstand high temperatures without oxidising.

She explained: “Avocado oil is growing in popularity, as similarly to extra virgin olive oil, it is mostly made up of monounsaturated fats. These are known to moderate inflammation and improve heart health by reducing LDL (‘bad’)cholesterol levels whilst increasing HDL (‘good’) cholesterol.

“It’s also a good source of antioxidants, including lutein, which is beneficial for eye health and may reduce the risk of age-related eye diseases. Refined avocado oil can withstand high temperatures without oxidising. Combined with its relatively neutral flavour, it’s a good alternative option when frying food.”

Ms Viljoen agreed, stating that avocado oil is “one of the most heat-stable oils available”.

“Its high monounsaturated fat content and high smoke point make it well suited to frying, grilling and higher-temperature cooking, with a neutral flavour,” she added.

What oils should be avoided?

Bailyn Fields, sales director at Boomer Benefits, said the most unhealthy oils are those high in saturated fat, which increase LDL (Low-Density Lipoprotein) cholesterol.

“That puts butter, ghee, lard, tallow, palm and coconut oil in the ‘use sparingly’ category, and research shows coconut oil raises LDL versus non-tropical vegetable oils,” said Fields.

“Industrial trans fats were the worst offenders historically, though they’ve been removed from many food supplies. Reused or overheated oils of any type can also degrade and form off-flavours and by-products, so avoid repeatedly frying with the same batch at home.”

Kate Styles, the founder of Keto Kitchen Lytham, said she tends to avoid seed oils such as sunflower, rapeseed and vegetable oil because they’re “highly refined and can become unstable when heated”.

She continued: “When oils oxidise at high temperatures, they can contribute to inflammation and are not something I believe belongs in nutrient-dense, real food.

“Choosing natural, stable cooking fats like butter, olive oil, and ghee is one of the simplest changes people can make to improve the quality of their diet, particularly for those following a low-carb or ketogenic lifestyle. These fats provide flavour, satiety, and consistency in cooking without the blood sugar spikes associated with highly processed alternatives.”

Ruth O’Sullivan, registered nutritionist at leading foodservice wholesaler Brakes, agreed that some fats are healthier than others, adding that eating too much saturated fat can negatively impact your heart health by increasing blood cholesterol levels.

Ms O’Sullivan said: “Saturated fat can be found in butter, lard, coconut oil and palm oil, so we should use less of these. Unsaturated fats, known as monounsaturated and polyunsaturated fats, are more heart-healthy.

“They’re found in sunflower, rapeseed and olive oils, so we should choose these types of oils to cook with. Just bear in mind that all cooking oils add fat and calories to your diet, so whichever you choose, use it sparingly.”

Steve Bennett, a PCI-Qualified Health Coach, said he tends to avoid industrial seed oils, which can promote inflammation. He said: “We’ve been sold a dangerous lie. Those ‘heart-healthy’ vegetable oils lining supermarket shelves-sunflower, corn, soybean-are modern industrial inventions your great-grandmother would never recognise. You’ve never seen an oil vegetable growing in a home garden, have you?

“Here’s what matters: these seed oils are loaded with omega-6 fatty acids that trigger chronic inflammation in your body. Think of inflammation as your body’s alarm system-brilliant for healing a cut or fighting infection, but catastrophic when it never switches off. Our modern diets, drowning in these industrial oils, keep that alarm blaring 24/7.

“The oils you can trust are the ones humans have used for centuries, but here’s the critical mistake I see constantly: using the wrong oil at the wrong temperature. When any oil reaches its smoking point, it transforms into trans fats and carcinogenic compounds. Olive oil is perfect for salads and low-heat cooking, but using it for high-heat frying is a common error. For high temperatures, use coconut oil, ghee, or even traditional lard and dripping-your grandmother’s secret ingredients that are far healthier than anything created in a factory.”

Ms Viljoen also suggested avoiding refined vegetable oils and seed oils such as sunflower, corn, soybean and any generic “vegetable oil” blends.

“These are highly processed, high in omega-6 fats and prone to oxidation, particularly at high temperatures,” she said.

“In summary, choose olive oil for everyday cooking, avocado oil or ghee for high heat, and nut or seed oils for cold use only. Avoid or minimise refined seed oils to reduce inflammatory load in the diet.”