A large study out of Spain sheds light on this question. After 11 years of follow-up studying over 40,000 people, the researchers found no association between consumption of fried foods and risk of coronary heart disease or all-cause mortality. This may seem contrary to what you’ve heard over the years, “Don’t eat fried foods. It’s not good for you.” What should we make of this study?
Let’s look at the details. This study was done on foods prepared in homes where the fats used were healthy fats, primarily olive oil and sunflower oil. Both of these fats fry well without any major breakdown of the fats. Most of the frying was simple pan frying and the fat was not used over and over as is done in commercial deep-fat frying where the fat tends to degrade over time.
Over the period of the 11 year study, there were 606 coronary heart disease events and 1135 deaths from all causes. Even when the researchers adjusted for other risk factors such as age, gender, BMI, education level, physical activity, alcohol, smoking, blood pressure etc. eating fried foods showed no increase in heart disease or death from any cause.
Keep in mind important points in this study. First, it was done in a country that eats a Mediterranean diet, which has been found to be health promoting compared to the Western diet. The fats used were olive oil and sunflower oil, not solid fats or deep fat frying oils that are high in trans fatty acids and which are used so commonly in Western societies and fast food restaurants. The authors point out that olive oil is less prone to oxidation than other plant oils and is free of trans fats. It is considered a “healthy fat” as is sunflower oil.
If you want to fry foods, keeps these goals in mind. Choose a fat such as olive or sunflower oil. When frying, use moderate amounts of a healthy oil to keep calorie levels moderate. Don’t use fats over and over again in frying, and when frying, be sure to keep the temperature of the frying moderate, below the smoke point of the fat. When the skillet gets hot enough to smoke, that is when bad things begin to happen with the oils. If you follow these guidelines, it appears that frying and sautéing vegetables etc. in a little olive oil in a skillet does not appear to be harmful.
On the other hand, if you fry with solid fats and fats high in trans fatty acids or saturated fats, or eat foods fried in deep fat frying that is reused multiple times to fry foods, this is a well-established hazard to your health. This kind of fat frying is what is done at most fast food places and is not good for your heart or longevity.
Pilar Guallar Castillon, et al. Consumption of fried foods and risk of coronary heart disease, British Medical Journal 2012, 344:e363, Jan. 24, 2012
Written by Don hall, DrPH, CHES