The myths of oils and fats

	Saturated	Mono-unsaturated	Poly-unsaturated	Hydrogenated / Trans fats
Processing	Natural, very little processing	Natural, some processing	Natural, some processing	Unnatural, extensive  processing
Naturally occurring in…	Coconut, butter, fat, animal tallow (fat from meat, e.g. goose fat)	Extra virgin/virgin: Olive oil, avocado oil (Rapeseed)	Virgin: Safflower, flax, sunflower, soy, sesame (Rapeseed)	Nothing!These don’t occur naturally, they are artificially produced.
Properties	Stable, heavy fats	Fairly stable, light oils	Fairly unstable, light oils	Stable, heavy fats (but different structure to natural saturated fats)
Visualise…	Dense, heavy, square	Light, circle	Light, circle	Dense, heavy, square with jagged edge
Best for…	cooking at high heating	Cooking but not at high heat	Cooking at low temperatures, adding to food	avoiding completely

Which fats and oils are good for us?

All natural fats are good for us in moderation.

Saturated fats and mono-unsaturated oils are best for cooking

Mono-unsaturated oils (extra virgin olive oil, extra virgin avocado oil) have many health benefits and are fairly stable to cook with at light to medium-high heats such as sauteing, baking and roasting to 175°C.  Extra virgin olive oil (EVOO) particularly contains many health promoting polyphenols.  Choose to cook with extra virgin olive oil when you aren’t going to very high heat.

Saturated fats are heat- and light-stable, these are the best fats to cook with (in moderate amounts) to high heat such as frying or tempering spices.  They can be heated to high temperatures and they don’t change their form or shape or disintegrate into harmful substances.  With the levels of meat and dairy in most of our diets, we generally get plenty of these so we don’t need to add them into our diets beyond cooking with them.

Poly-unsaturated fats are best for cooking at low temperatures or adding to food

Seed oils high in polyunsaturated fats such as flax, sunflower, sesame and soy are very beneficial to the body if used unprocessed and unheated or only heated to low temperatures.   They help to reduce blood pressure, develop and promote a healthy brain and prevent arthritis.  Some of them are essential in our diets (i.e. our bodies can not make them).

If we cook to higher heats with these oils, they can break down, forming free radicals – toxic, aging molecules.  These toxic chemicals break down essential structures in the body (it is to combat these that we take anti-oxidants such as vitamin C).

These oils should not be heated to high heat.  Sunflower, sesame and soy oils can be used for low heat cooking such as gentle sauteing but flax oil should not be cooked with at all.  All of them can be poured on meals and used in dressings, which is a great way to get the health benefits from them.

A note on which oils to buy:

To make these unsaturated vegetable oils easier to extract and able to sit on supermarket shelves in clear plastic bottles, manufacturers use intense treatment processes, including heat, to treat these oils.  Whilst some people (such as Zoe) believe these processes don’t cause negative health outcomes, we see that level of processing as too much and would advise avoiding.  We’re happy to revise this opinion if very long term studies indicate they are adverse outcome free but until then, we’ll be buying our oils unprocessed.  Therefore we recommend only buying virgin, cold pressed oils which are in dark bottles (protection from light).  Don’t buy standard vegetable oils you find in plastic bottles on supermarket shelves.

Hydrogenated and trans fats are best for … avoiding completely

Saturated fats such as butter are versatile and stable but expensive.  To create cheaper fats, companies started making artificial saturated fats by processing unsaturated fats (vegetable and nut oils).  These processes form hydrogenated fats and trans fats.  These fats look and feel quite similar to natural fats but with some important differences in shape.  The body thinks they are same as the natural fats and uses them for the same jobs.  Given that they are actually different, they don’t work and our systems, such as cell messaging, fail to work properly.  This has large knock-on effects on the body.

Do not eat anything with hydrogenated or trans fats in them – this will include many processed foods and commercially baked goods such as biscuits and cakes.  Margarine can also contain these.  In the UK, these are now rarely found in foods but do keep your eyes out for them.

In summary

COOKING AT HIGH HEAT

• Saturated fats for high heat cooking e.g. frying, tempering spices. These are very heat-stable and do not become toxic on heating.  These include ghee (clarified butter), butter, coconut oil and animal fats such as duck and goose fat.  The best among these is ghee as it contains beneficial nutrients (vitamin A, D, E & K, linoleic acid) and is the only fat which stimulates the digestive fire (capability).  Use saturated fats in moderation and never deep-fry.

COOKING UP TO MEDIUM HEAT (PREFERRED OIL FOR MOST USE)

• Mono-unsaturated fats for low to medium-high heat cooking, e.g. sauteing, baking and roasting up to 175°C. Cooking a pasta sauce, for example, where there a little gentle frying followed by addition of watery ingredients which cools down the temperature is a great use for these.  These are extra virgin olive oil and extra virgin avocado oil.  Make sure these oils are kept in dark bottles, away from sunlight. Be careful; don’t expose the oil to too high or prolonged heat.

COOKING AT LOW HEAT

• Poly-unsaturated oils such as sunflower, sesame and soy all have fabulous health benefits and can be heated to low heats such as with gentle sauteing.

POURING COLD ONTO FOOD

• Poly-unsaturated oils such as flax, hemp, almond and walnut are very beneficial in the diet but don’t heat them.  Add them to food or take them neat (especially flax oil).

AVOID

• Heat processed oils, hydrogenated and trans fats.

Author: Kate Siraj, Ayurvedic Practitioner, BSc Ayurveda, MChem (Oxon), MAPA.

© The Ayurveda Practice

Further information:

1. Mann, J and Truswell, S (ed) (2002): Essentials of Human Nutrition. Oxford: Oxford University Press, 2^nd edition.
2. Fox, BA and Cameron, AG (1995). Food Science, Nutrition and Health. London: Edward Arnold. 6^th edition.
3. Erasmus, U (1993): Fats that heal, Fats that kill. Canada: Alive Books