Cooking oils
Which oil?
When you are frying or cooking at a high temperature (at or close to 180C), fats (such as butter) and oils undergo oxidation - react with oxygen in the air to form aldehydes and lipid peroxides. [Lipids are a group of molecules that include fats.] At room temperature something similar happens, though more slowly, eventually becoming rancid
Consuming aldehydes has been linked to increased risk of heart disease and cancer.
Oils which were rich in polyunsaturates - corn oil and sunflower oil – produce very high levels of aldehydes when heated to high temperatures. They’re OK if you don’t heat them at standard frying temperatures.
Olive oil and cold-pressed rapeseed oil produce far less aldehydes, as does butter because they are richer in mono-unsaturated and saturated fatty acids, which are much more stable when heated. In fact, saturated fats hardly undergo this oxidation reaction at all.
Use olive oil for frying or cooking, firstly because lower levels of these toxic compounds are produced and secondly because the compounds that are formed are actually less threatening to the human body.
Frying in saturate-rich animal fats or butter may be preferable to frying in sunflower or corn oil.
Avoid poly-unsaturates.
Try to do less frying. Fry at lower temp. Minimise the amount of oil you use. Remove the oil from the outside of the fried food, perhaps with a paper towel.
To reduce aldehyde production go for an oil or fat high in monounsaturated or saturated lipids (preferably greater than 60% for one or the other, and more than 80% for the two combined), and low in polyunsaturates (less than 20%).
Best oil for cooking purposes is olive oil because it is about 76% mono-unsaturates, 14% saturates and only 10% polyunsaturates.
When it comes to cooking it doesn't seem to matter whether the olive oil is ‘extra virgin’ or not. The antioxidant levels present in the extra virgin products are insufficient to protect us against heat-induced oxidation. [Well, extra virgin is supposed to be worse than ordinary olive oil!]
Keep your oils in a cupboard, out of the light, and try not to reuse them as this also leads to the accumulation of nasty side-products.
Info on fats: Poly-unsaturated fats contain two or more carbon-carbon double bonds. When eaten in as food such nuts, seeds, fish and leafy greens, they have clear health benefits. However, the benefits of consuming sunflower oil and corn oil, although rich in polyunsaturates, are much less clear.
Mono-unsaturated oils contain just one carbon-carbon double bond. They are found in avocados, olives, olive oil, almonds and hazelnuts. Olive oil, which is approximately 76% mono-unsaturated, is a key component in the Mediterranean diet, which has been shown to significantly reduce the risk of heart disease.
Saturated fats have no double bonds between carbon atoms. Although we are encouraged to switch from eating saturated fats, particularly dairy and other fats derived from animals, the benefits of doing so are being challenged.
Type of oil or fat Polyunsaturated (%) Monounsaturated (%) Saturated (%)
Coconut oil 2 6 86
Butter 3 21 51
Lard 11 45 39
Goose fat 11 56 27
Olive oil 10 73 13
Rapeseed oil 28 63 7
Sesame oil 41 40 14
Corn oil 54 27 12
Sunflower oil 65 20 10
There is now mounting evidence that eating some saturated fats may actually help you lose weight and be good for the heart. Researchers have been unable to find convincing evidence that eating saturated fats leads to greater risk of heart disease. There is good evidence that eating a handful of oily nuts a few times a week will reduce your risk of heart disease, despite the fact they are contain saturated and unsaturated fats.
Prof says: "It's very clear that cattle that are fed on pasture have very, very different fatty acid patterns from cattle that are corn-fed. So I think how the animal has been reared probably has a big impact in its nutrient profile and, presumably, on health outcomes, which may be why there's such conflicting evidence, because it depends on where the source of your food comes from."
When you are frying or cooking at a high temperature (at or close to 180C), fats (such as butter) and oils undergo oxidation - react with oxygen in the air to form aldehydes and lipid peroxides. [Lipids are a group of molecules that include fats.] At room temperature something similar happens, though more slowly, eventually becoming rancid
Consuming aldehydes has been linked to increased risk of heart disease and cancer.
Oils which were rich in polyunsaturates - corn oil and sunflower oil – produce very high levels of aldehydes when heated to high temperatures. They’re OK if you don’t heat them at standard frying temperatures.
Olive oil and cold-pressed rapeseed oil produce far less aldehydes, as does butter because they are richer in mono-unsaturated and saturated fatty acids, which are much more stable when heated. In fact, saturated fats hardly undergo this oxidation reaction at all.
Use olive oil for frying or cooking, firstly because lower levels of these toxic compounds are produced and secondly because the compounds that are formed are actually less threatening to the human body.
Frying in saturate-rich animal fats or butter may be preferable to frying in sunflower or corn oil.
Avoid poly-unsaturates.
Try to do less frying. Fry at lower temp. Minimise the amount of oil you use. Remove the oil from the outside of the fried food, perhaps with a paper towel.
To reduce aldehyde production go for an oil or fat high in monounsaturated or saturated lipids (preferably greater than 60% for one or the other, and more than 80% for the two combined), and low in polyunsaturates (less than 20%).
Best oil for cooking purposes is olive oil because it is about 76% mono-unsaturates, 14% saturates and only 10% polyunsaturates.
When it comes to cooking it doesn't seem to matter whether the olive oil is ‘extra virgin’ or not. The antioxidant levels present in the extra virgin products are insufficient to protect us against heat-induced oxidation. [Well, extra virgin is supposed to be worse than ordinary olive oil!]
Keep your oils in a cupboard, out of the light, and try not to reuse them as this also leads to the accumulation of nasty side-products.
Info on fats: Poly-unsaturated fats contain two or more carbon-carbon double bonds. When eaten in as food such nuts, seeds, fish and leafy greens, they have clear health benefits. However, the benefits of consuming sunflower oil and corn oil, although rich in polyunsaturates, are much less clear.
Mono-unsaturated oils contain just one carbon-carbon double bond. They are found in avocados, olives, olive oil, almonds and hazelnuts. Olive oil, which is approximately 76% mono-unsaturated, is a key component in the Mediterranean diet, which has been shown to significantly reduce the risk of heart disease.
Saturated fats have no double bonds between carbon atoms. Although we are encouraged to switch from eating saturated fats, particularly dairy and other fats derived from animals, the benefits of doing so are being challenged.
Type of oil or fat Polyunsaturated (%) Monounsaturated (%) Saturated (%)
Coconut oil 2 6 86
Butter 3 21 51
Lard 11 45 39
Goose fat 11 56 27
Olive oil 10 73 13
Rapeseed oil 28 63 7
Sesame oil 41 40 14
Corn oil 54 27 12
Sunflower oil 65 20 10
There is now mounting evidence that eating some saturated fats may actually help you lose weight and be good for the heart. Researchers have been unable to find convincing evidence that eating saturated fats leads to greater risk of heart disease. There is good evidence that eating a handful of oily nuts a few times a week will reduce your risk of heart disease, despite the fact they are contain saturated and unsaturated fats.
Prof says: "It's very clear that cattle that are fed on pasture have very, very different fatty acid patterns from cattle that are corn-fed. So I think how the animal has been reared probably has a big impact in its nutrient profile and, presumably, on health outcomes, which may be why there's such conflicting evidence, because it depends on where the source of your food comes from."