(28-07-09) What Went In When Trans Went Out?

To the Editor: Industrially produced trans fatty acids in popular foods such as fast foods, cookies, cakes, and snacks1 are gradually being replaced in the United States and Western Europe by other fatty acids because of societal pressure and legislative regulations.2 This movement is driven by increasing scientific evidence of the harmful effects of industrially produced trans fatty acids on health, especially the increased risk of coronary heart disease,3 and by the lack of evidence of any beneficial health effects. The consumption of trans fatty acids is associated gram for gram with a greater risk of coronary heart disease than is the consumption of saturated fatty acids. The risk of trans fatty acids is even more pronounced as compared with that of monounsaturated fatty acids and especially polyunsaturated fatty acids.4 Despite the obvious theoretical health benefits of replacing trans fatty acids with other fatty acids in food products, concern has been expressed that this change might increase the intake of saturated fatty acids.5 In light of this concern, we have investigated various popular foods that contain high concentrations of trans fatty acids. We have examined which types of fatty acids are present in these foods as compared with similar foods that contain low concentrations of trans fatty acids.
Nineteen food items containing a high amount of trans fatty acids and 19 similar food items containing a low amount of trans fatty acids were purchased from large supermarkets and fast-food outlets in 14 countries from 2005 through 2008. The fatty acid profiles were analyzed, and similar types of foods bought in the same country were compared.
The results are shown in Figure 1. French fries, cookies, cakes, and microwave-oven popcorn with low concentrations of trans fatty acids had higher concentrations of saturated, monounsaturated, and polyunsaturated fatty acids than did corresponding products with a high content of trans fatty acids. In french fries with a low trans fatty acid content, as compared with french fries with a high trans fatty acid content, the average proportion of fatty acids from trans fatty acids decreased by 18 percentage points, the proportions from saturated fatty acids and monounsaturated fatty acids were the same, and the proportion from polyunsaturated fatty acids increased by 19 percentage points. The corresponding comparisons for microwave-oven popcorn were as follows: trans fatty acids, ?46 percentage points; saturated fatty acids, +24 percentage points; monounsaturated fatty acids, +15 percentage points; and polyunsaturated fatty acids, +8 percentage points. For cakes and cookies, the corresponding comparisons were trans fatty acids, ?40 percentage points; saturated fatty acids, +33 percentage points; monounsaturated fatty acids, +5 percentage points; and polyunsaturated fatty acids, +4 percentage points.

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Figure 1. Trans Fatty Acids and Saturated, Monounsaturated, and Polyunsaturated Fatty Acids as Percentages of Total Fatty Acids.
The average increase or decrease in percentage points is shown for foods with a low amount of trans fatty acids as compared with similar foods with a high trans fatty acid content, according to country.


In most countries, popular foods with high levels of trans fatty acids and foods with low levels are available at similar prices. Our data show that the trans fatty acids in these foods can be replaced with a mixture of saturated, monounsaturated, and polyunsaturated fatty acids. The nutritional benefit of this shift in fatty acid composition for popular foods is even greater than the benefit of a one-to-one substitution of trans fatty acids with saturated fatty acids.

Steen Stender, M.D.
Arne Astrup, M.D.
J?rn Dyerberg, M.D.
Gentofte University Hospital
2900 Hellerup, Denmark
[email protected]
References
1. Stender S, Dyerberg J, Astrup A. High levels of industrially produced trans fat in popular fast foods. N Engl J Med 2006;354:1650-1652. [Free Full Text]
2. L'Abb? MR, Stender S, Skeaff M, Ghafoorunissa, Tavella M. Approaches to remove trans fats from the food supply in industrialized and developing countries. Eur J Clin Nutr 2009;63:Suppl 2:S50-S67. [Medline]
3. Mozaffarian D, Katan MB, Ascherio A, Stampfer MJ, Willett WC. Trans fatty acids and cardiovascular disease. N Engl J Med 2006;354:1601-1613. [Free Full Text]
4. Mente A, de Koning L, Shannon HS, Anand SS. A systematic review of the evidence supporting a causal link between dietary factors and coronary heart disease. Arch Intern Med 2009;169:659-669. [Free Full Text]
5. Aro A. The scientific basis for trans fatty acid regulations -- is it sufficient? A European perspective. Atheroscler Suppl 2006;7:67-68. [Web of Science][Medline]

Source: NEJM :Volume 361:314-316
July 16, 2009

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