Is butter better that margarine?

BUTTER v MARGARINE

Russell Setright

A little butter may be better than margarine, particularly the margarine uses in many packaged foods. Many of these foods contain trans-fats and the amount is not always displayed on the label.

There are many studies which confirm the possible dangers of using margarine and other foods that are high in trans-fatty acids and these studies confirm that the intake of margarine is associated with increased risk of heart attacks.

Trans fats are a particular type of fats that may be produced industrially as partially hydrogenated oils or that are naturally present in food products made from ruminant animals such as dairy products and meat from cattle, sheep or goat.

Heart disease is the leading cause of death in Australia and a high intake of TFA seriously increases the risk of heart disease  more than any other nutrient on a "per calorie" basis.

Trans-fatty acids & coronary heart disease.

Trans-fatty acids are found in many packaged foods. They are the result of partial hydrogenation of vegetable oils to produce margarines and shortening. It is known they can increase the ratio of LDL to HDL cholesterol, which may have an adverse effect on cardiovascular disease. In the Nurses Health Study, while evaluating over 85,000 females for cardiovascular disease risk, it was found that the consumption of trans-fatty acids was directly related to the risk of coronary heart disease even when controlling for other risk factors. The risk was stronger for those who had consumed margarine at a constant rate over the last 10 years. Foods that were higher sources of trans-fatty acids include margarines, cookies, biscuits, cakes and white bread. These foods are associated with a higher risk of coronary artery disease.

(Willott, Walker C., et al "Intake of Trans Fatty Acids and the Risk of Coronary Heart Disease Among Women", , The Lancet, March 6, 1993;341:581-585).

Trans-fats in foods

This letter to the editor notes that partial hydrogenation of liquid vegetable oils is a major source of trans-fatty acids which may increase serum levels of low density lipoprotein and decrease high density lipoprotein cholesterol. These hydrogenated vegetable oils are frequently seen in margarine and vegetable shortening. Even through these foods contain no cholesterol, they may have adverse consequences on heart disease. The fast-food industry switched from beef tallow to these vegetable oils because of consumer demand. The intake of trans-fatty acids from the average diet may be high enough to have an adverse effect on dietary treatment, of hypercholesterolemia. The authors conclude that patients and physicians may want to be aware of these artificial sources of fatty acids in their food choices.

Litlin, Lisa, R.D. and Sacks, Frank, M.D.,"Tran-Fatty Acid Content of Common Foods",  New England Journal of Medicine, December 23, 1993:329(26):1969-1970).

Heart attack & trans-fatty acids

This study evaluated the relationship between trans-fatty acids and acute myocardial infarction in 239 patients admitted to 1 of 6 hospitals in the Boston area, and 282 population controls. After adjustment for variables, the intake of trans-fatty acids was directly related to the risk of heart attacks. Intake of margarine, the major source of trans-isomers, was also associated with an increased risk of heart attacks. The authors conclude this data supports the hypothesis that intake of partially hydrogenated vegetable oils may contribute to the risk of myocardial infarction. 

(Ascherio, Alberto, M.D., et al, "Trans-Fatty Acids Intake and Risk of Myocardial Infarction", Circulation, 1994;89:94-101).

The presence of small amounts of trans fat in hydrogenated or partially hydrogenated oils/food products such as margarine will likely cause many to exceed their recommended maximum of 2g daily. Greater transparency in labelling and/or active consumer education is needed to reduce the cardiovascular risks associated with trans fats. (Remig, V. et al. Trans Fats in America: A Review of Their Use, Consumption, Health Implications, and Regulation, Journal of the American Dietetic Association Vol. 110, Issue 4, April 2010, Pages 585–592)