Sugar gets a lot of attention in the media and rightly so – however it isn’t the only culprit with respect to our increasingly poor health. The current nutrition dogma encourages reduced amounts of fat because science links cholesterol (of which animal fat is rich in) to cardiovascular disease. Because of this, there has been an influx of processed food that has replaced saturated fat for vegetable oils.
These vegetable oils include soybean oil, canola oil, margarine, rice bran oil, sunflower oil and olive oil spreads (which contain olive oil, but are predominantly a vegetable oil blend) The process of extraction (i.e. see here this video) which includes bleaching and deodorizing, strips these oils of any nutrients they may have contained.
These oils are high in omega-6 fats, which are polyunsaturated fats and are vulnerable to destabilisation due to many double bonds present in their chemical structure. It is this destabilisation that can trigger inflammatory pathways in the body, linking the intake of vegetable oils and high amounts of polyunsaturated fats stored in the body, to elevated risk of chronic disease.
First, let’s be clear. There is a link between saturated fat in the bloodstream and cholesterol. There is also a link (in the laboratory, when tested on rabbits) between cholesterol levels and atherosclerosis. However, the amount of saturated fat in the bloodstream is determined by the amount of sugar in our diet and not saturated fat in food. When it comes to cardiovascular disease over half of the population who have heart attacks have a low cholesterol level. Not all people who have high cholesterol levels go on to have a heart attack, and more and more health professionals are understanding that cholesterol levels are just one risk factor for heart health – and perhaps not even an important one in most people.
The real underlying issue is inflammation. Saturated fat in food is fairly benign when it comes to inflammation. Polyunsaturated fats, particularly the omega-6 fats, play right in to this inflammatory pathway and in fact it is the presence of omega-6 fats in the blood that is linked to elevated cardiovascular disease. However the long held belief that saturated fat is bad for our health led the movement for vegetable oils to be used as a replacement and considered a healthy alternative.
Certainly there are health benefits of having omega-6 fats; they are essential in the body and help cognitive function, growth and development. They also reduce inflammation when in the correct ratio with omega-3 polyunsaturated fats. This ratio is around 4:1 omega 6 to omega 3. However (as with many things) the poison is in the dose and in the western diet, the ratio is close to 18:1 in favour of omega 6 fats, due to the proliferation of vegetable oils that are consumed via processed food and food prepared and eaten outside of the home.
Excess omega 6 fatty acids are stored in the body as opposed to being used for energy and are sensitive to physiological chemical reactions that occur. They react with oxygen and this causes our cell membranes to become oxidised, driving the inflammatory process. This inflammation not only increases the risk of cardiovascular disease but can alter the structures that ensure the integrity of our gut and the gut microbiome. We are beginning to understand just how important our gut microbiome is in determining our health, and therefore anything threatening the gut microbiome, such as these vegetable oils, may have consequences far beyond what we know now in terms of our health.
Mikki Williden - Real Food Nutritionist http://mikkiwilliden.com/
For more on Vegetable Oils click here
For more on how to maximise you Omega-6 to Omega-3 ratio click here