Fried foods are not bad for the heart, if…
Posted by medconsumers on February 1, 2012
Regularly eating fried foods is not bad for the heart—if they are fried in olive oil or sunflower oil. This from a new study conducted in Spain where these two oils are used most often for frying —both at home and restaurants. Unfortunately, this good news may not be relevant to Americans whose fried food consumption most likely takes place at fast food chains where olive and sunflower oils are as rare as a side order of kale.
At the start of this study, reported last week in the British Medical Journal, the 40, 757 participants, aged 29-69, did not have heart disease. All had filled out extensive questionnaires about their usual diet and food preparation. The average daily intake was nearly 5 ounces of fried foods, including about 1 tablespoon of oil for frying. About 7% of the total amount of food consumed was fried. The study started in 1992. Eleven years later, there were 606 heart-related “events” like heart attack and stroke and 1,134 deaths from all causes.
One might have expected the heart attacks and strokes to be clustered among the study participants who regularly ate the highest amount of fried foods. But this was not the case. In fact, there was no relationship between the amount of fried foods and the rate of death from any cause or the rate of heart-related “events” (i.e., from heart attacks to the need for angioplasty).
These findings should be understood in the context of the Mediterranean diet and the characteristics of the study participants: Two-thirds were women who as a group reported eating a lower amount of fried foods than the men, thus bringing down the average intake of fried foods. The participants lived in five regions of Spain that traditionally have widely varying diets. Sixty two percent were using olive oil for frying and the rest used sunflower oil or other (2%) vegetable oils.
Fried foods make up a large percentage of the diet of all Mediterranean countries. Here’s the breakdown according to the types of foods the Spanish study participants were most likely to be frying: 24% fish, 22% meat, 21% potatoes, and 11% eggs. The research team, led by Pilar Guallar-Castillón, University of Madrid, pointed out that consumption of fried foods in Spain is not a proxy for fast food intake. “Fast foods are generally prepared by deep frying with oils used several times, and are consumed mostly away from home. In Spain, fried foods are consumed both at and away from home, and both deep frying and pan frying are used. Moreover, we can assume that oil is not reused many times for foods consumed at home; however, the cardiovascular effects of food fried with overly reused oils merit further research. Finally, consumption of fried snacks high in salt is fairly low in Spain, whereas in other countries such as the United States they provide an important percentage of energy intake.”
This study was based on the Spanish people who had volunteered to participate in a much larger project called the European Prospective Investigation into Cancer and Nutrition. It was described in the accompanying editorial as the most “comprehensively investigated” study of a potential link between heart disease and fried foods. An earlier study, also conducted in Spain, had found a link between hypertension and the consumption of foods fried in reused oil. But hypertension is one of many factors that put people at risk for heart disease. This is the first study to show no link between between intake of fried food and important outcomes like death, stroke, and heart attack.
Want to know more about frying and how it changes the nutritional content of food? Here’s how the Spanish researchers described the motivation for their study:
“When food is fried its nutritional content changes—the food loses water and takes up fat, increasing its energy density. Frying modifies both the foods and the frying medium because oils deteriorate during frying, especially when reused, through the processes of oxidation and hydrogenation, leading to a loss of unsaturated fats and an increase in trans fats. Thus fried food absorbs degradation products of the frying oil. At the same time, frying may also improve palatability by making food crunchy.”
Maryann Napoli, Center for Medical Consumers(c)