Fat content and fatty acid composition of seed oils
From Udo Erasmus' book,
Explanation of chemical symbols:
18:3w3 = 18 carbon fatty acid with three double bonds at the 3, 6, and 9 carbon positions, and w3 means that first double bond is at 3. carbon position
w = [read "omega"]
Fat content and fatty acid composition of seed oils (%)
|fatty acid percentage in oil|
|Name||Fat Content in seed
* Includes up to 2% GLA - Gamma Linolenic Acid
** Includes 9% GLA
*** Includes up to 5%erucic acid
|Linoleic Acid (LA)
|Alpha Linolenic Acid (LNA)
Prolonged absence of LA from diet is fatal. All of the deficiency symptoms (except death) can be reversed by adding LA back to the diet from which it was missing.
LA is found in safflower, sunflower, hemp, soybean,walnut, pumpkin, sesame, and flax.
Safflower and sunflower are the richest source of LA.
These symptoms can be reversed by adding LNA back to the diet from which it was missing. Other symptoms that can result from LNA (or w3) deficiency include :
These are not considered 'classic' symptoms of w3 deficiency, but often respond remarkably well to w3 supplementation.
LNA is five times more unstable than LA and modern people consume 10 times less LNA then LA.
LNA is found in flax, hemp seed, canola(rape seed), soybean, walnut and dark-green leaves. Flax seed is the richest source, containing over 50% of its fatty acids as LNA. Chia and kukui (candlenut) oils contains about 30% LNA. Hemp seed oil contains about 20% LNA. Pumpkin seed oil contains between 1% and 15% LNA. Canola oil contains up to 10% LNA and Walnut oil contains between 3% and 11% LNA.
FATS - What are the real issues?
A lot has been said about fats, much of it confusing, some of it misleading. You should have a clear, sensible approach to fat consumption in a healthy diet by following these simple guidelines:
- Good balance in diet between LA(w6) and LNA(w3) fatty acids is (w3) LNA 1:2 LA (w6)
- Modern diet imbalance: (w3) LNA 1:10 LA (w6)
|Modern diet: from||
|Canola (Rape seed)||1||:||4|
- Use only cold pressed (expeller pressed) nonrefined oils, ( keep refrigerated )and non heated not exposed to the light or air
- No margarine (margarine is made from hydrogenated fats, and refined oils, that why it is hard )
- No Hydrogenated Fat ( HF ) (HF is made from trans fatty acids)
- No Oils from Supermarket , they are heated and refined (EFA are removed) (transparent bottle means that oil will not be harmed by light, and that mean that oil does not have EFA ); If oil is kept in the usual shelves (out of refrigerator) that mean that oil does not have EFA
- The most dangerous fats are typically found in margarine, shortenings, and heated oils.
Essential Fatty Acids (EFAs) Chemical Formulas
This EFA is called Linoleic Acid (LA) and is poly-unsaturated. LA is an 18 carbon chain fatty acid with two double bonds in the middle and is missing four hydrogen atoms, all on one side. The first double bond occurs after the 6th carbon atom. Because of this, LA is sometimes referred to as the W6 EFA. Because of the four missing hydrogen atoms, LA is even more bent than Oleic Acid, giving it a melting temperature of 23 degrees F (-5C). LA is fairly unstable, reacting with light and oxygen.
This is Alpha Linolenic Acid (LNA). It is an 18 carbon fatty acid with three double bonds at the 3, 6, and 9 carbon positions. LNA is missing 6 hydrogen atoms, again all from one side. Because of the first double bond occurring at the 3rd carbon atom, LNA is sometimes referred to as the W3 EFA. It is sometimes referred to as a super unsaturated fatty acid (SUFA), even though it is also poly-unsaturated. Because LNA is bent more than the others, it has the lowest melting point of the three, 10 degrees F (-12 C). (I have a bottle of it in my freezer and it is still liquid!). LNA is 5 times more unstable than LA and quickly goes rancid if exposed to light or oxygen. It is so unstable, in fact, that when it is pressed from the seeds that possess it, the pressing must be done in the total absence of light and oxygen. It must be handled in this way right through to the packaging stage, then quickly refrigerated or frozen.