Ask a Dietitian

As seen on BCTV October 15/02

The question should not be which is better, but which is worse.

Both are 81% fat.
Both contain 9 kcal/gram
Both contain a mixture of fats – mono, poly, saturated and trans. The difference is in the percentage of each type of fat.

In hard margarine there are trans fatty acids formed through hydrogenation of vegetable oil. Trans fats will raise LDL (bad) cholesterol and decrease HDL (good) cholesterol.

Non-Hydrogenated margarine is mostly unsaturated and is cholesterol-free. Non-hydrogenated margarines also contain some saturated fats in them to make them solid at room temperature but this margarine has a more favorable effect on our cholesterol by reducing LDL. Butter is mostly saturated fat and contains cholesterol. Research shows that a diet high in saturated fat and cholesterol has been associated with an increase in total and LDL cholesterol. However, in butter, not all the saturated fatty acids will cause a rise in cholesterol. The short chain fatty acids and stearic acid have no effect or a lowering effect on cholesterol. Moreover, some of the cholesterol that is elevated is good cholesterol (HDL).

A study done studying the effects of 6 different fats on the cholesterol levels of men and women found that compared to those eating butter LDL cholesterol was 12-9% lower in those eating soy oil, semi-liquid and soft tub margarine and 7-5% lower in those eating shortening and stick margarine. However, the stick margarine also lowered the good cholesterol which made it the worst of all. In summary, butter and stick margarine have the worst effect on LDL (bad) cholesterol, but stick margarine also lowers HDL (good) cholesterol. Non-hydrogenated margarine has the most favorable effect on cholesterol.

When we evaluate these fats in terms of cancer risk the verdict changes. Butter contains anticarcinogens such as conjugated linoleic acid (CLA), butyric acid and sphingolipids. Linoleic acid in corn oil, safflower and sunflower oils is carcinogenic and our diet has significantly more of this type of fat now than in the past. There is a positive correlation between linoleic acid and the risk of prostate cancer.

So what’s the verdict?
Emphasize olive or canola oils, which are primarily monounsaturated fats, high in linolenic acid which is non-carcinogenic and has a favorable effect on our blood cholesterol levels. Use olive oil or canola oils in cooking and for dipping bread. If you use margarine make it non-hydrogentated. Butter vs. non-hydrogenated margarine – Use non-hydrogentaed margarine in you have high cholesterol, otherwise go for taste and use them sparingly. Avoid stick and hydrogenated margarines.

Most importantly, recognize that butter really only constitutes 4-6% of the calories in the diet and the other 24-26% of the calories from fat are from other foods. Many of which contain hydrogenated fats. Read food labels and avoid foods that contain hydrogenated vegetable oils or vegetable oil shortening. Foods that commonly contain these fats include baked goods, cookies, crackers, granola and processed foods.

Watch for the Eating for Energy segment every Tuesday on BCTV’s Noon News Hour!