In today’s health-conscious environment no other part of our diet receives more attention than fat. For the majority of us, one of the most prevalent sources of fat in the home is the cooking oil we use to prepare our food with.

A Complex Relationship

Forty years ago the western world began to markedly increase its consumption of polyunsaturated oils due to the health benefits they were thought to offer. In the last decade or two, however, it has become apparent that a far more complex relationship exists between fats/oils and our health than the simplistic polyunsaturated vs saturated divide.

To make informed decisions about which cooking oils to use we must first understand the effects the different classifications of fat have on our bodies.

Saturated Fats

Saturated fat is found mainly found in meat, eggs and dairy products, but also occurs in certain vegetable oils such as coconut oil, palm kernel oil and cottonseed oil.

Saturated fats have gained a rather sinister reputation due to their role in raising Low Density Lipoprotein (LDL), or “bad” cholesterol blood levels. High LDL levels have been associated with coronary heart disease, stroke, prostate cancer and arterial plaques.

It should be noted, however, that saturated fat is a necessary component of a healthy diet. It just needs to be kept within safe limits. The American Heart Association, for instance, recommends its intake shouldn’t exceed 7% of total calories.

Polyunsaturated Fat

Generally derived from vegetable sources. Safflower oil, sunflower oil, grape seed oil, soybean oil are all rich in polyunsaturated fat.

The intake of polyunsaturated fats has been shown to lower LDL – the reason for their spectacular popularity over the past half century. But polyunsaturated oils also lower High Density Lipoprotein (HDL), or “good” cholesterol. While this lowering of HDL isn’t desirable, the overall cholesterol-lowering effect of polyunsaturated oils still ranks them above saturated fats health-wise.

Monounsaturated Fat

Most famously associated with olive oil, but also found in canola and rice bran oils, avocados and nuts, monounsaturated fats, not only lower LDL, they also actually raise HDL.

Choosing Your Oil

So, it seems simple enough – avoid lard and butter and do your cooking with either a poly- or monounsaturated oil. Well, it’s a good start, but there’s more to it than that.

When oil is heated it breaks down, degrades and can form toxic substances. The temperature at which oils do this is call their smoke, or burn, point. Different oils have different smoke points. Oils, then should be chosen according to the type of cooking you intend to do with them.

Smoke Points

Saturated fats are very stable at high temperatures and are therefore good for high temperature deep frying.

Polyunsaturated oils like safflower, sunflower, and soybean oils have relatively high smoke points and are acceptable for frying and sautéing. The monounsaturated rich oils peanut and rice bran also function well in this temperature range.

More delicate oils, like extra virgin olive oil and sesame oil should be treated carefully. Because of their low smoke points they are suitable for low temperature cooking and for use in salad dressings and dips etc.

Generally the more refined an oil is, the higher it’s smoke point will be. The smoke point of extra virgin olive oil, for instance, is 190˚C, while that for extra light olive oil is 242˚C.

It’s Not Just the Saturates

As well as the cholesterol-lowering effects of the various oils, attention should be paid to the other nutrients they can provide. Rice bran oil, one of the new stars of the oil world, contains vitamin E and a plant sterol called oryzanol which reduces cholesterol absorption. Olive oil carries polyphenols (antioxidants which diminish free radicals) and certain phytochemicals thought to aid the dilation of blood vessels and decrease inflammation in the body.

A Final Word

Many foods purported to have health benefits undergo reassessment as medical and scientific knowledge about them increases. Oils are no exception. Some studies of saturated fats now indicate that they may not be as dangerous to our health as was once thought. Conversely, it is now suspected that consuming high amounts of polyunsaturated oils, once the darlings of the oil world, may increase the risk of metastasis in cancer patients.

If you’re serious about your health you can’t treat cooking oil as just something that stops the food from sticking to the pan. It is a food in its own right and carries with it own set of benefits and dangers. So, next time you’re in the supermarket facing those shelves of golden bottles, choose carefully – remember, it’s more than just saturated vs. polyunsaturated.

Cooking Oil – What’s Healthy, What’s Not, 4.0 out of 5 based on 2 ratings

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