One of the major shifts that occurred in our diet after the Second World War was the widescale introduction of vegetable oils to replace traditional fats such as butter, lard and beef tallow.

Such oils were cheap to manufacture and gave the growing grain commodities markets another profitable income. Such a radical departure from our traditional fat intake was deemed justifiable under the auspices of preventing heart disease; remember Ancel Keys?

Except that the countries he left out of the presented data, not to mention indigenous populations such as the Masai and Pacific islanders, all showed low incidences of heart disease when fat was eaten as 40% or more of calorie intake.

So, along with soaring sugar and grain consumption, began a large experiment in human dietary evolution. Never before had we consumed such vast quantities of refined plant oils such as sunflower, cottonseed, soya and corn oils.

To extract the oils they were processed at high temperatures, refined, deodorised, and for margarine, coloured yellow (in some US states it was pink!).

In pastries and biscuits, vegetable oils could be ‘solidified’ to behave more like saturated fat, though decades later it emerged that these ‘trans-fats’ were highly toxic to normal cell function.

Other dangers have since become apparent.

Vegetable oils are highly vulnerable to heat and light, so cooking with them destroys the delicate fatty acids and produces free radicals, which can damage healthy cells.

These oxidised fats can also contribute to artery damage and general inflammation, a double whammy that can lead to heart disease and stroke.

Because vegetable oil also suppresses the thyroid and lower metabolic rate, they play a part in obesity and diabetes, making cells resistant to the insulin they need to process glucose and other nutrients. In the West, researchers estimate that we are consuming about 20 times the amount of omega 6 (the principle fatty acid found in vegetable oils) than is necessary.

For millions of years we ate mainly saturated and mono-unsaturated fats, supplemented with small amounts of omega 6 and 3 found in wild grass-fed animals and fish. We ate offal and animal fats including the marrow.

This diet enabled our brains to evolve and ensured remarkable fitness (Ice Age human remains indicate that we had remarkably tall and strong skeletons). These fats were also full of the soluble vitamins we needed for proper brain, muscle, hormone and nerve development: vitamins A, D, E and K.

Vegetable oils not only do not contain these nutrients (apart from palm oil, which is a saturated fat rich in carotene) but because they turn rancid in the body, anyone eating them needs to ensure they are consuming extra antioxidants such as Vitamins C and E, to protect their cells and arteries.

Trouble is, vegetable oils tend to be found in calorie-dense, processed foods, and those who consume the greatest amount tend to be the same people who eat the least amount of antioxidant-rich fresh foods. Couple this with the widespread (and false) belief that saturated and old-fashioned animal fats are unhealthy, and we really have a recipe for a modern health disaster.

Elizabeth Wells is a nutritionist and health writer. She specialises in chronic disorders, allergies and difficult-to-treat conditions.

You can contact her at www.naturallywells.com

Readers who submit articles must agree to our terms of use. The content is the sole responsibility of the contributor and is unmoderated. But we will react if anything that breaks the rules comes to our attention. If you wish to complain about this article, contact us here

Readers who submit articles must agree to our terms of use. The content is the sole responsibility of the contributor and is unmoderated. But we will react if anything that breaks the rules comes to our attention. If you wish to complain about this article, contact us here