杏吧原创

FISH and chips and other fried foods are taking yet another battering.

Last week Swedish researchers raised the alarm that fried, grilled or baked foods, such as French fries, contain unexpectedly high concentrations of acrylamide, a known carcinogen (www.newscientist.com). Now health conscious eaters face another alarm. A food researcher in Cyprus is warning that food fried in vegetable oil may clot your blood and clog up arteries.

Ioannis Patrikios of the Cypriot government鈥檚 Institute of Neurology and Genetics was shocked to find human red blood cells clotting after he鈥檇 mixed them in a test tube with a range of heated edible oils. 鈥淚t鈥檚 possibly toxic,鈥� he says. However, there鈥檚 no evidence yet that the same thing happens in the body.

Clotting only occurred after Patrikios heated the oils for 24 hours at 100 掳C. Nothing happened when the oils鈥攊ncluding corn, sunflower and virgin olive oil鈥攚ere unheated. He says the clotting is caused by highly reactive free radicals released by polymers that form in heated oleic acid, a fatty acid found in almost all edible oils. Patrikios believes the radicals make the cells stickier.

Although he has no proof, he suspects that this is what would happen if oils containing the polymers are absorbed from food. 鈥淔rom the literature, we know oils are absorbed through the gut,鈥� he says. Usually, he says, about a fifth of the oil we eat is absorbed.

Patrikios hopes to secure funding to investigate whether eating food cooked in hot oil thickens the blood. He wants to test if the polymer gets into blood or membranes. Experts at Britain鈥檚 Food Standards Agency (FSA) agree that these experiments are crucial to establishing whether there is a genuine hazard. 鈥淲ithout this, any conclusions relative to human health are highly speculative,鈥� says a spokeswoman. Nor is it likely that anyone would continually heat cooking oil for 24 hours, she says.

Nevertheless, Patrikios urges people to cut down on meals fried in oil, and advises them not to reuse it, as oils accumulate more oleic-acid polymer each time they are heated. He says that chip fat could become steadily more dangerous if the same oil was used again and again. Patrikios also warns that the polymers form if oils are exposed to light for prolonged periods. As a precaution, he recommends storing oils in dark cupboards, or putting them in opaque bottles.

The FSA, however, is more sanguine. Rather than fretting over speculative warnings, it says people should eat a healthy balanced diet by cutting down on fatty foods and eating more fruit and vegetables.