Posted on: by Alistair
The answer to this question:
Which oil should I use for cooking?
contains a degree of complexity because it requires some understanding of the chemical nature of oils along with an understanding of how oils are manufactured. However, if you’re just looking for the answer without the background… ghee and sesame (and olive oil if you’re not cooking with too much heat).
Fats are split into two general categories – saturated and unsaturated.
Saturated fats are:
- Heat stable
- Have a high smoke point
- Solid at room temperature
Unsaturated fats are:
- Heat unstable
- Have a low smoke point
- Liquid at room temperature
Saturated oils are heat stable because have single bonds between the individual carbon atoms of the fatty acid chain. This is important because double bonds are weak and can break apart easily – releasing free radicals. Single bonds also result in a higher smoke point – referring to the temperature at which an individual oil begins to break down and release the free radicals. Free radicals are the chemicals which cause oxidation in the body (rapid aging) and out of the body (causing iron to rust).
So the more a fat is saturated the less likely it is to deteriorate and cause tissue and cellular damage. Free radicals are released each time the oils are heated which is why restaurants are not allowed to heat oil more than a handful of times (it becomes more toxic each time until it is ultimately fatal). However, in modern nutrition we are told not to cook with saturated fats as they will cause congestive problems (blocked arteries).
So, let’s look at unsaturated oils. Unsaturated oils are further divided into two categories: monounsaturated and polyunsaturated. Monounsaturated fats have a single carbon double bond in the fatty acid chain. By contrast, polyunsaturated fats have more than one double bond.
When mono and poly-unsaturated fats (which are not heat stable) are heated they release or provoke free radicals. Biochemical scientists state that the oils high in polyunsaturated fats are the most prone to deteriorate in cooking and so should not be used to fry foods in. This is also the Ayurvedic point of view. The exception to this decay seems to be oils that are balanced in polyunsaturated and monounsaturated fats (containing as close to 50% of each).
Sesame oil contains a balance of poly and monounsaturated fats (46% and 41% respectively) while olive oil, which modern nutrition considers to be an ideal cooking oil, contains 8% polyunsaturated and 82% monounsaturated bonds – much too far from ideal the 50/50 split if you’re cooking with it.
Another point to consider when deciding the best oil to use is to consider how the oil was produced. Heat extracted processes yield three times as much oil as cold-pressed oil but the oil is no longer heat stable because it has been heat extracted. Oil technically becomes “synthetic” after 320° F when the fatty-acids become “trans fatty-acids“. Chemical extraction does not make the oil heat unstable, however, all the chemicals used in the extraction remain in the oil.
So which oil is the best for cooking and eating?
The good news is that there are two fats that provide the ideal characteristics of a cooking oil and both are nutritious and Ayurvedically balancing (to a degree).
The first is a classic oil used in Ayurveda (and throughout the Middle East) – sesame oil. Sesame oil is the most stable of all vegetable oils and the least likely to oxidize and cause the proliferation of free radicals. Cold-pressed and organic sesame oil is ideal as it is heat stable, easily digested and will contain no chemicals from the farming or extraction process.
Ghee is also a fantastic oil to cook with because it is heat stable (a saturated fat), it has a cleansing action on the liver (liquifies congestion which then moves into the intestines) and it removes Ama from the system if it is taken in small quantities (1 tsp). In the Western world nutritionists have discovered that the use of olive oil actually helps to clear and clean the bile ducts of the gall bladder and liver. In India it is known that ghee has the same affect as olive oil, but on ALL of the channels and ducts of the body. Ghee differs from butter as the milk solids have been removed and so it is far less congestive.
Ghee and sesame are not recommended for Kapha but good for Pitta and Vata.