Despite its bad reputation, fat is an essential nutrient in our diets. However, all fats are not created equal. Consuming too much of the wrong kinds of fat can be dangerous. Trans and saturated fats are found in animal-based foods (meat and dairy), tropical oils, and fried foods. Excessive consumption of these fats has been shown to significantly increase the risk of heart disease and heart attacks. Polyunsaturated fats (PUFAs) and monounsaturated fats (MUFAs), on the other hand, are the healthy fats commonly found in non-tropical oils, fish, and nuts. Diets rich in these fats have been shown to reduce the risk of heart disease.
When people make the decision to lower their intake of saturated fats, they generally replace them with other foods to keep their consumption of total calories the same. Researchers from the Institute of Preventative Medicine in Copenhagen, Denmark, wanted to know if it was better to replace saturated fats with PUFAs, MUFAs, or carbohydrates. Their study, published in the American Journal of Clinical Nutrition, demonstrated that PUFAs are the best choice for replacing calories from saturated fats in the diet.
Researchers combined data from 11 American and European cohort studies in which a total of 344,696 participants free of known heart disease were followed for a period of 4-10 years. During that time, 5,249 participants had a coronary event (eg, heart attack) and 2,155 died from heart disease.
Participants lowered their consumption of saturated fats by 5% and replaced these lost calories with either PUFAs, MUFAs, or carbohydrates. The rates of coronary events and deaths in each group at the end of the follow-up period were:
It is essential to include a certain amount of fats in your diet, about 20%-35% of your total calories. The majority of these fats should be PUFAs and MUFAs. This study indicates that replacing saturated fats with PUFAs is more likely to prevent heart disease. PUFAs are common in oily fish and nuts but can also be found in many oils in combination with MUFAs. While MUFAs did not demonstrate a clear benefit in this study, other research supports their benefits to the heart. MUFAs are always a better choice than saturated or trans fats. Apparently, substituting carbohydrates may not be the best option.
To replace saturated and trans fats with PUFA and MUFA, try substituting meat meals with fish once or twice week, and use canola oil or olive oil instead of coconut or palm oils. Instead of snacking on fried foods like potato chips (rich in saturated fats and carbohydrates) try some almonds or walnuts. When choosing high-fat condiments like butter or mayonnaise, look for options higher in MUFAs and PUFAs and low in saturated fats. The information is available on the nutrition label. None of this is difficult to do, and the food you eat will taste just as good.
American Dietetic Association
American Heart Association
Jakobsen MU, O’Reilly EJ, Heitmann BL, et al. Major types of dietary fat and risk of coronary heart disease: a pooled analysis of 11 cohort studies.Am J Clin Nutr. 2009 May;89(5):1425-32. Epub 2009 Feb 11.
Last reviewed May 2009 by Richard Glickman-Simon, MD