Happy Mardi Gras! French for “Fat Tuesday,” this February holiday celebrates the close of the pre-Lenten season. The name stems from the custom of using all the fats in the home before Lent in preparation for fasting and abstinence. We thought this would be a good time to make sure you know which fats you should seek out because they are actually good for you, and which fats you should avoid.
Important Nutrients. Dietary fat is critical for the absorption of fat-soluble nutrients, including vitamins A, D, E, and K. It also helps enhance the flavor of foods. Some fats serve as the starting material for important substances like hormones, inflammatory factors, and vitamin D. But not all fats are created equal. Simply put, the components that make up fats come in different shapes and sizes, and these factors determine how they behave in our bodies.
For the most part, we consume fats in the form of triglycerides, which are three fatty acids joined together. The body breaks down triglycerides into individual fatty acids, which are then absorbed and eventually enter the bloodstream. If we take in more energy (calories) than we need, the body converts the fatty acids back into triglyceride form and stores them in adipose (fat) cells for later use.
Key Categories. Saturated fatty acids—the predominant fatty acids in butter, whole milk, cheese, meat, tropical oils (coconut, palm, and palm kernel oil), and many products made with these ingredients—raise your blood levels of LDL (bad) cholesterol, which is associated with higher risk for heart disease.
Unsaturated fatty acids are the most prevelant fatty acids in plant oils such as soybean, canola, and olive oil; fish/seafood; and plant foods such as nuts, seeds, and avocados. The two major subgroups of unsaturated fatty acids, mono- and polyunsaturated, are generally found together in foods in varying relative amounts.
In contrast to saturated fatty acids, unsaturated fatty acids can actually lower your blood levels of LDL (bad) cholesterol. (This association is stronger for polyunsaturated than monounsaturated fatty acids, but they are all good choices). Consuming unsaturated fats in place of saturated fat is good for heart health. This means choosing foods like plant oils and foods made with them (such as salad dressings), fish/seafood, nuts, seeds, and avocados in place of animal fats (from dairy and meats).
The Essentials. Some omega-3 and omega-6 polyunsaturated fatty acids are essential: they are necessary for the body to function properly, and we must get them from food.
Omega-3 fatty acids gained popularity after researchers discovered eating fish and seafood (which are high in omega-3s) was associated with better cardiovascular health. Dietary patterns rich in omega-3s are consistently associated with positive health effects. This may be in part because eating more fish usually means eating less meat and cheese. The results of studies on the impact of fish oil supplements on health have been inconsistent.
Omega-6 polyunsaturated fatty acids are found in more foods than omega-3s. (see “The Good Fats: Sources of Unsaturated Fatty Acids”) The most common omega-6 fatty acid, linoleic acid, is an essential fatty acid plentiful in most plant oils, nuts, and seeds. Linoleic acid is crucial for normal growth, development, and brain function. Replacing foods high in saturated fatty acids with those high in omega-6 fatty acids has cardiovascular benefits.
You may have heard omega-6 fatty acids increase inflammation in the body, but many of the studies backing this claim were performed on animals fed very high levels, and this effect has not been observed in humans. A large volume of research supports a strong beneficial relationship between omega-6 fatty acids and positive health outcomes in humans.
Trying to avoid all fat can limit your intake of heart-healthy unsaturated fats and essential fatty acids, does not support the absorption of fat-soluble vitamins, and makes room on your plate for unhealthy refined carbohydrates. Instead of throwing out all the fat in your house this “Fat Tuesday,” check your dietary habits and see where you can choose foods high in unsaturated fatty acids in place of those high in saturated fatty acids.