This is possibly the most confusing topic in the field of nutrition, and the problem is made worse because in many cases, nutritionists, doctors and scientists really don’t’ know all the answers.
Fats have been classified into 2 groups:
1. The degree of saturation – monounsaturated fats, polyunsaturated and saturated fats. In recent years trans fat have also been added to this group
2. And whether they are omega 3 or omega 6 fats.
Degree of saturation. Fats have a “backbone” of carbon atoms all joined together by bonds, like thread through a string of beads. If there is a single bond, then each carbon atom has 2 hydrogen atoms attached to it.
• If all carbons have just a single bond, then the fat is called saturated – it is saturated with hydrogen. This is the composition of most animal fats and some tropical oils, such as coconut oil.
• If there is one double bond, then it is mono-unsaturated. For example olive oil, almond, peanut, cashew and avocado oils.
• If there are a number of double bonds, then it is poly-unsaturated. Most vegetable oils are poly-unsaturated, they are liquid at room temperatures and are prone to oxidation and rancidity.
• A new group of fats, artificially produced from poly-unsaturated fats, are the Trans fats. These are a completely different shape, can easily pack together and very likely cause heart disease and perhaps other diseases of today. Trans fats are found in many margarines and spreads, cake mixes, baked goods, fried fast food, potato chips, whipped toppings … read the label and void them.
Suffice to say, our grandparents and forefathers all ate fully saturated animal fats, and had much less coronary heart disease and cancer than we currently have.
• We have no doubt that monounsaturated fats such as olive oil and fish oil fats are good for us, unless they are heated repeatedly, when they can turn into trans fats.
• Poly-unsaturated fats are probably good, but not too much
• Saturated fats: caution and don’t overdo them
• Trans-fats: these are pure evil, and should be avoided if at all possible. But in today’s world, this is almost an impossibility.
Omega 3 vs omega 6 fats – our liver can make most of the fats oru body requires with two exceptions – Linoleic Acid (omega 6) – BAD and alpha linolenic (omega 3) – GOOD. These have very similar names, but their effects within the body are totally different. However the important point is that it is a matter of balance. Let’s look at each in turn:
Linoleic acid is omega 6 which turns into arachidonic acid AA which promotes inflammation, and is very useful for fighting infections. It helps white blood cells to find an attack bacteria and viruses, boosts the immune system, makes the blood more likely to clot, closes up the arteries and also can narrow the bronchi going to the lungs.
So, although omega 6 fats have a good side, because we have them in excess in our diet and our bodies, we regard them as bad.
While these are all handy in the presence of an infection, at other times these actions can hurt the body, causing heart attacks, asthma, inflammatory bowel disease and arthritis.
Alpha linolenic acid is omega 3 and is found in cold water fatty fish and flax and some other seed oils. This turns into Eicosapentaenoic acid (EPA) which does the opposite to AA. It reduces inflammation, dilates the arteries and the bronchi and reduces the clotting tendency of the blood. It also blocks some of the unnecessary damaging effects of AA on the body.
So omega 3 oils are powerful “treatments” for any disease caused or aggravated by inflammation such as arthritis, inflammatory bowel disease and asthma. People are beginning to realize that the onset of a heart attack in many cases is initiated by inflammation, so omega 3 oils are very important in people with coronary artery disease.
So we need a little omega 6 oil (AA) to fight infections and stay protected, and some omega 3 (EPA) to protect the body, and the best amount is the ratio of 4 to 1 (AA: EPA). But in our Western diet, the ratio is more like 40-80 to 1. Is it surprising that we have so much inflammatory (immune) diseases and heart disease?
The answer – cut down on the red meat, egg yolks and animal fats, and also increase the amount of omega 3 oils (flax seed and fish oils), to get the ratio closer to the healthy 4 to 1. Our bodies will thank us for that.