OIL is used mainly for cooking. Yet this vital fact gets forgotten when nutritionists, doctors and other health authorities recommend which oils to use.

The standard advice is that we should avoid saturated fats and use more unsaturated fats - avoid butter, lard, coconut oil and palm oil, switch to margarine, corn oil, etc.

This is not always good advice. Because polyunsaturated fats are generally not good for cooking. They are easily damaged by heat. Once damaged, they become very toxic.

Fast food chains switching to vegetable oil for flying is therefore not good news. It is bad news.

It is true that saturated fats and cholesterol are bad for health. They cause blockages in the blood vessels, leading to heart attacks.

Unsaturated fats are thus seen as the miracle answer to heart disease.

Essential

Vegetable oils are recommended because they contain no cholesterol. And except for coconut and palm oils, which contain mainly saturated fats, other vegetable oils contain high proportions of unsaturated fats.

Moreover, vegetable oils are rich in essential fatty acids. These are fats which we must have. We cannot make them in our bodies; we must obtain them from foods.

Essential fatty acids - particularly linoleic acid (LA) and linolenic acid (LNA) - are the most important fatty acids in human nutrition and health. They are abundant in the oils of nuts and seeds.

There are good reasons, therefore, why we should use more vegetable oils and less - or no - animal fat.

But vegetable oils spoil easily. Light, air (oxygen) and heat are the ~ main factors that cause oil to spoil. And spoilt oil is very harmful.

When exposed to light and air, oils tend to oxidise and form toxic by-products. Heating the oil, especially heating it to high temperatures for a long time (more than 15 minutes) speeds up this process.

Heating also produces unstable molecules called free-radicals. These try to stablilise themselves by taking electrons away from other molecules, making other molecules unstable in the process. A chain reaction is sparked off and free radicals keep being formed.

One of the most harmful heating processes is hydrogenation, where a liquid oil is heated to a very high temperature and reacted with hydrogen under high pressure. This is used in the manufacture of margarine and other hydrogenated (or partially hydrogenated) fats used in chocolates, candies and even "health" snacks.

Hydrogenation changes these fatty acids into trans-fatty acids. In layman terms, it means that a good fat has been turned into a harmful fat.

These changes caused by heating oil leads to a host of health problems, including higher risks of cancer, liver damage and heart disease.

A good oil - from the nutritional viewpoint - is therefore not the same as a good cooking oil.

'The trouble is, most oils are already "cooked" by the time they reach us. The manufacturing process involves heating seeds and nuts to high temperatures to extract the oil.

Chemical solvents are also used. The oils are further refined, bleached, de-gummed, deodorized, winterized (to remove cloudy matter), treated with antioxidants and modified in various other ways.

In the process, the oil loses its vitamin E (which prevents oxidation), beta carotene (which protects us against cancer) and other nutrients. Meanwhile, a host of chemicals are added, many of them known or suspected to be cancer-causing.

"The highly refined oils which we find in transparent bottles on supermarket shelves should not be used for anything," Udo Erasmus writes in Fats and Oils.

The ‘best’ oils

"Why? Because they have been degraded by light, have lost much of their nutrient value during the refining process, and are usually made from the cheapest, most inferior, most intensely pesticide sprayed oil plants.

"Oil should be fresh, unrefined, mechanically pressed, organically grown, and stored in dark containers," Erasmus adds.

To provide good nutrition, an oil must contain high levels of linoleic acid (LA), linolenic acid (LNA) and other essential fatty acids.

Erasmus lists "the best oils" as follows: flax, hemp, pumpkin, walnut and soy.

All spoil easily. All are not good for cooking and should be consumed fresh. And are all hard to find.

Flax was widely used in Europe before the Second World War, and its history dates back thousands of years. But it is now rarely produced for human consumption because it spoils within five months even if it is properly stored.

Hemp oil is illegal because it comes from marijuana seeds. Pumpkin and walnut oils are available at heath and specialist food stores.

Most soybean oil is refined. Soybeans contain very little oil (18 per cent) and the oil is hard to extract without chemical solvents. It is better to eat the beans, Erasmus advises.

The next three "good oils" on Erasmus' list are: safflower, sunflower and evening primrose.

Unrefined safflower and sunflower oils are available. But they usually come in transparent bottles and had been exposed to light.

Again, all three oils are not good for cooking. Evening primrose is a special oil used only for therapeutic purposes, and is sold in capsules.

Oils suitable for cooking come further down the list: sesame, grape seed, corn and rice bran.

These are happy compromises. They contain adequate levels of essential fatty acids, and they remain fairly stable when heated.

Cotton, rapeseed (canola) and peanut oils are also good, both nutritionally and in term of heat stability.

But they have potential problems. Both cotton and canola oils contain natural toxins, while peanut oil may contain afiatoxins, which is linked to liver cancer, if the nuts had fungus.

Further down the list are olive and almond oils. "Almond and olive oils are nice," Erasmus notes, "but too low in essential fatty acids to be good for people on a diet which also contains large quantities of saturated animal fats." He recommends these oils for massage.

Still further down are coconut and palm oils. Nutritionally, they are considered poor as they contain mostly saturated fats.

But they are good for cooking at high temperature - baking and deep frying - because heat doess not convert them into poisons.

Finally, there is butter, ghee, lard and other animal fats. Again, they are not very nutritious, but excellent for high heat cooking.

The best oils for cooking, then, are the worst oils from the nutritional point of view.

Nutritious oils are best taken raw. But taking too much raw oils may not be good either.

From the macrobiotic viewpoint, oil is considered very yin. And the nutritionally superior unsaturated oils are more yin than saturated fats.

Taking too much raw, unsaturated oils would therefore result in an overly yin condition and poor physical health.

Traditional

One way out of this dilemma is to compromise. Cook with oils that are nutritionally adequate, yet stable when heated - sesame, grape seed, corn and rice bran oill.

In macrobiotic terms, these are considered the least yin of all vegetable oils. They provide more balanced energy than the extreme yin oils like sunflower and safflower, or the more yang animal fats.

Except for grape seed, these oils have also been used in traditional societies for thousands of years.

Traditional methods of cooking also helped to minimise the harmful effects of heat damage.

"In traditional Chinese cooking," Erasmus points out, "the first thing the cook puts into the wok is not oil, but water. The water keeps the temperature down to 100 deg C, and the water vapour (steam) protects the oil from air.

"In European gourmet cooking, the vegetables are placed in the frying pan before the oil is added, and protect the oil from overheating and oxidation."

For baking, Erasmus suggests lining the baking tin with butter. Less stable oils can be used for cakes or whatever is being baked, as the moisture keeps it from overheating.

What about deep frying? Well, it is not a common traditional practice. In the old days, oil was costly and few could afford the luxury of eating deep fried foods.

Oils traditionally used for deep frying include butter, ghee and coconut oil. They are mainly saturated fats, and not good for health. But at least they are riot as harmful as unsaturated oils that have been damaged by the intense heat.

The more stable vegetable oils are okay if you take care not to let the oil smoke. Macrobiotic cookery teacher Margareta Cherry finds from experience that a combination of grape seed, sesame and olive oil (in decreasing proportions) works well.

Because different oils have different boiling temperatures, combining them tends to produce better results in deep frying.

Corn oil is not suitable for deep frying because it foams easily.

One other traditional practice is worth noting. The Japanese always serve fried foods with grated daikon (white radish). It helps to digest the oil and eliminate toxins.

Our ancestors knew better. They didn't worry about saturated or unsaturated fats, nor about heart disease and cancer.

http://udoerasmus.com/articles/udo/udo_index.htm

This Web Page was created on 15 October 1997 & updated on 14 April 2007 by H J Heng