French fries and chicken nuggets from two major global fast-food chains contain very high levels of artery-clogging 鈥渢rans鈥� fats, researchers warn. And the level of trans-fats served by the chains varies dramatically from country to country.
Researchers who analysed the fast food say that daily consumption of 5 grams or more of trans fats raises the risk of heart attack by 25%. Half of the 43 鈥渓arge鈥�-sized fast food meals, 24 from McDonald鈥檚 and 19 from KFC, examined in the study 鈥� purchased in outlets around the world 鈥� exceeded the 5 gram level.
Trans fats are thought to pose a hazard by raising the proportion of 鈥渂ad鈥� cholesterol in the blood, leading to the accumulation of fat in arteries. Trans fats also increase the risk of arterial inflammation and the development of an irregular heartbeat.
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鈥淭hat鈥檚 why it鈥檚 called 聭killer fat鈥�,鈥� says Steen Stender of the Gentofte University Hospital in Copenhagen, Denmark, and lead author of the analysis in The New England Journal of Medicine.
Some combinations of 鈥渓arge鈥� fries and 鈥渓arge鈥� chicken nuggets from McDonald鈥檚 and Kentucky Fried Chicken outlets contained between double and five times the 5-gram danger level.
Industrial-grade oil
Stender says that consuming such food regularly could drastically increase someone鈥檚 risk of a heart attack, but the fast food companies could solve the problem by changing the industrial-grade oil they use to prepare the food.
鈥淭he good thing about trans fatty acids is that it鈥檚 easy to remove them,鈥� notes Stender. 鈥淲hen you enter a McDonald鈥檚 or a KFC, you should be entering a trans-fatty-acid-free zone,鈥� he adds.
In a review of trans fats in the same journal, Walter Willett at the Harvard School of Public Health in Boston, US, and colleagues, conclude that in the US alone, complete removal of the industrially-produced trans fats from food preparation could prevent up to 228,000 heart attacks per year in the US.
Peak levels
The fats are convenient for the fast food industry because they can be used repeatedly to fry foods at high temperatures without breaking down chemically. But manufacture of the industrial-grade cooking oils vastly increases the proportion of trans fats in the oil, from zero to as much as 60%.
In Stender鈥檚 analysis, the fries and nuggets containing the most trans fat had invariably been cooked in oil that was itself high in fat.
The highest levels of all were found in a meal from a KFC in Hungary which contained 25 g of trans fats, and had been cooked in oil containing 35% trans fats. Levels were also high in KFC meals bought from Poland (20 g), Peru (16 g) and the Czech Republic (15 g).
The highest-scoring McDonald鈥檚 meal was from New York, US (10 grams), cooked in oil containing 23% trans fats.
Corporate public relations
Both companies say they are committed to phasing out the trans fats from their cooking oils. 鈥淲e鈥檙e at the early stages of reviewing alternative oils options, which includes looking at local taste preferences, supply availability, storage, as well as other factors such as functionality,鈥� Christophe Lecureuil of KFC International told New 杏吧原创.
鈥淢cDonald鈥檚 takes the matter of trans fatty acids seriously,鈥� says Catherine Adams, vice president of worldwide quality systems, food safety and nutrition at McDonald鈥檚. 鈥淥ur reduction in the US is taking longer than anticipated, as we have previously announced. But we continue to progress in our testing and we are determined to get it right for our customers.鈥�
Stender found that levels of trans fats were much lower in merchandise from most West European countries, and were virtually undetectable in fries and nuggets from Denmark, where it has been illegal since 1 January 2004 to sell food with levels of trans fats exceeding 2% of the total fat in a food product. 鈥淚t took less than three months for the industry to remove it,鈥� Stender points out.
Journal reference: The New England Journal of Medicine (vol 345, p 1650)
