High Levels of Industrially Produced Trans Fat in Popular Fast Foods
http://www.100md.com
《新英格兰医药杂志》
To the Editor: The daily intake of about 5 g of trans fat is associated with a 25 percent increase in the risk of ischemic heart disease.1 For this reason, it is recommended that the consumption of trans fat be as low as possible.2 We determined the content of industrially produced trans fatty acids in 43 servings of fast foods bought in 20 countries between November 2004 and September 2005. We and our colleagues decided which cities to include in the study on the basis of planned visits for other purposes. The foods (chicken nuggets and french fries) were purchased from McDonald's and KFC outlets.
The foods were homogenized, and the fatty acid content was analyzed by capillary gas chromatography according to a method3 accredited by the International Organization for Standardization. For comparison, the amounts of trans fatty acids in the french fries and chicken nuggets were expressed as the amounts in a serving size equal to that of a large serving of the food from McDonald's (171 g of french fries and 160 g of chicken).4
The content of trans fatty acids varied from less than 1 g in Denmark and Germany to 10 g in New York (McDonald's) and 24 g in Hungary (KFC) (Figure 1). Fifty percent of the 43 servings contained more than 5 g per serving — the amount of daily intake associated with a 25 percent increase in the risk of ischemic heart disease.
Figure 1. A Comparison of the Amounts of Industrially Produced Trans Fatty Acids in a Large Serving of Fast Food from Two Outlets in Various Countries.
The values in parentheses on the y axis are trans fatty acids as a percentage of the total fat found in 43 servings of french fries and chicken nuggets purchased at McDonald's or KFC.
The cooking oil used for french fries in McDonald's outlets in the United States and Peru contained 23 percent and 24 percent trans fatty acids, respectively, whereas the oils used for french fries in many European countries contained only about 10 percent trans fatty acids, with some countries as low as 5 percent (Spain) and 1 percent (Denmark). At KFC, some values for trans fatty acid content were above 30 percent. Within the same chain in the same country, large variations in these values were observed — for instance, between KFC outlets in Hamburg and Wiesbaden in Germany and between Aberdeen and London in the United Kingdom.
Owing to the very high content of industrially produced trans fatty acids in certain fast foods, in many countries it is possible to consume 10 to 25 g of these trans fatty acids in one day and for habitual consumers of large amounts of this food to have an average daily intake far above 5 g. This is a matter of concern, particularly for low-income people, who already have an increased risk of ischemic heart disease owing to other lifestyle factors.
Denmark introduced legislation, effective January 1, 2004, restricting the use of industrially produced trans fatty acids to a maximum of 2 percent of the fat in any food product.5 The experience with the Danish surveillance system and the results of our study demonstrate that this health risk can be eliminated without any noticeable effect for the consumer.
Steen Stender, M.D.
J?rn Dyerberg, M.D.
Gentofte University Hospital
DK-2900 Hellerup, Denmark
stst@gentoftehosp.kbhamt.dk
Arne Astrup, M.D.
Royal Veterinary and Agricultural University
DK-1958 Frederiksberg C, Denmark
References
Oomen CM, Ocke MC, Feskens EJ, van Erp-Baart MA, Kok FJ, Kromhout D. Association between trans fatty acid intake and 10-year risk of coronary heart disease in the Zutphen Elderly Study: a prospective population-based study. Lancet 2001;357:746-751.
Letter report on dietary reference intakes for trans fatty acids. Washington, D.C.: National Academy Press, 2002. (Accessed March 23, 2006, at http://www.iom.edu/file.asp?id=13083.)
Leth T, Bysted A, Hansen K, Ovesen L. Trans FA content in Danish margarines and shortenings. J Am Oil Chem Soc 2003;80:475-478.
McDonald's nutrition information. (Accessed March 23, 2006, at http://www.mcdonalds.com/usa/eat/nutrition_info.html.)
Stender S, Dyerberg J. The influence of trans fatty acids on health. 4th ed. 2003. (Accessed March 23, 2006, at http://www.ernaeringsraadet.dk/pdf/Transfedt_UK_ny.PDF.)
The foods were homogenized, and the fatty acid content was analyzed by capillary gas chromatography according to a method3 accredited by the International Organization for Standardization. For comparison, the amounts of trans fatty acids in the french fries and chicken nuggets were expressed as the amounts in a serving size equal to that of a large serving of the food from McDonald's (171 g of french fries and 160 g of chicken).4
The content of trans fatty acids varied from less than 1 g in Denmark and Germany to 10 g in New York (McDonald's) and 24 g in Hungary (KFC) (Figure 1). Fifty percent of the 43 servings contained more than 5 g per serving — the amount of daily intake associated with a 25 percent increase in the risk of ischemic heart disease.
Figure 1. A Comparison of the Amounts of Industrially Produced Trans Fatty Acids in a Large Serving of Fast Food from Two Outlets in Various Countries.
The values in parentheses on the y axis are trans fatty acids as a percentage of the total fat found in 43 servings of french fries and chicken nuggets purchased at McDonald's or KFC.
The cooking oil used for french fries in McDonald's outlets in the United States and Peru contained 23 percent and 24 percent trans fatty acids, respectively, whereas the oils used for french fries in many European countries contained only about 10 percent trans fatty acids, with some countries as low as 5 percent (Spain) and 1 percent (Denmark). At KFC, some values for trans fatty acid content were above 30 percent. Within the same chain in the same country, large variations in these values were observed — for instance, between KFC outlets in Hamburg and Wiesbaden in Germany and between Aberdeen and London in the United Kingdom.
Owing to the very high content of industrially produced trans fatty acids in certain fast foods, in many countries it is possible to consume 10 to 25 g of these trans fatty acids in one day and for habitual consumers of large amounts of this food to have an average daily intake far above 5 g. This is a matter of concern, particularly for low-income people, who already have an increased risk of ischemic heart disease owing to other lifestyle factors.
Denmark introduced legislation, effective January 1, 2004, restricting the use of industrially produced trans fatty acids to a maximum of 2 percent of the fat in any food product.5 The experience with the Danish surveillance system and the results of our study demonstrate that this health risk can be eliminated without any noticeable effect for the consumer.
Steen Stender, M.D.
J?rn Dyerberg, M.D.
Gentofte University Hospital
DK-2900 Hellerup, Denmark
stst@gentoftehosp.kbhamt.dk
Arne Astrup, M.D.
Royal Veterinary and Agricultural University
DK-1958 Frederiksberg C, Denmark
References
Oomen CM, Ocke MC, Feskens EJ, van Erp-Baart MA, Kok FJ, Kromhout D. Association between trans fatty acid intake and 10-year risk of coronary heart disease in the Zutphen Elderly Study: a prospective population-based study. Lancet 2001;357:746-751.
Letter report on dietary reference intakes for trans fatty acids. Washington, D.C.: National Academy Press, 2002. (Accessed March 23, 2006, at http://www.iom.edu/file.asp?id=13083.)
Leth T, Bysted A, Hansen K, Ovesen L. Trans FA content in Danish margarines and shortenings. J Am Oil Chem Soc 2003;80:475-478.
McDonald's nutrition information. (Accessed March 23, 2006, at http://www.mcdonalds.com/usa/eat/nutrition_info.html.)
Stender S, Dyerberg J. The influence of trans fatty acids on health. 4th ed. 2003. (Accessed March 23, 2006, at http://www.ernaeringsraadet.dk/pdf/Transfedt_UK_ny.PDF.)