Fat is made up of building blocks called fatty acids. This is true of both the fat in food and the fat in our bodies. When you eat a food containing fat, your body breaks it into fatty acids.
On a molecular level, fatty acids are long chains of carbon atoms with some hydrogen atoms attached. Small differences in structure make a big difference in how fatty acids behave. There are four types of fatty acids:
- Saturated: The carbon chains of saturated fats have no open spots on their chain for hydrogen atoms. That is why they are called saturated. They raise LDL cholesterol (the "bad" cholesterol) and increase the risk of heart disease
- Monounsaturated: These fatty acids are missing one of their hydrogen atoms due to one double bond between carbon molecules. Sometimes called MUFAs, monounsaturated fats are healthier than saturated fats.
- Polyunsaturated: These fatty acids are missing more than one of their hydrogen atoms. Sometimes called PUFAs, these fatty acids have significant health benefits. Omega-3 and omega-6 fatty acids belong to this group.
- Trans fats: This type of fat is rare in nature but has been widely used in processed foods. Trans fats are created by adding hydrogen molecules to unsaturated fats to make them shelf-stable. Trans fats are generally unhealthy, and the Food and Drug Administration (FDA) regulates their use in food products.
Why You Need Fatty Acids
Although all fats are built of fatty acids, most discussion of fatty acids centers around the polyunsaturated and monounsaturated types. The omega-3s and omega-6s are especially important. They are known as essential fatty acids because the body cannot manufacture them. They must be consumed in food.
Most foods contain a mixture of fats. Even foods that contain healthy fatty acids may contain some saturated fats. Read labels and choose foods with the best ratio of healthy fats and unhealthy fats.
It's also important to remember that all fats are high in calories and should be used sparingly. Otherwise, they may lead to obesity and the associated health challenges.
If you are wondering whether you get enough “good” fatty acids in your diet, the answer is not simple. The U.S. Dietary Guidelines contain no guidelines for most fatty acids. There is a recommendation for linolenic acid (an omega-3) and for linoleic acid (an omega-6) for children and young adults. For most people, the goal should be a well-balanced diet in which healthy fatty acids have taken the place of most saturated fats.
The benefits of fatty acids are found mainly in monounsaturated and polyunsaturated fats:
One of the best things you can do for your heart is to replace saturated fats in your diet with unsaturated fats. Healthier fats reduce your cholesterol levels and cut your risk of heart attack and stroke.
The American Heart Association recommends that people limit their intake of saturated fats to 5 to 6% of their caloric intake and their intake of trans fats to less than 1%.
Omega-3s and omega-6s are both necessary for skin health. They keep skin elastic and reduce the effect of UV rays on the skin. They also help the skin function as a barrier, keeping moisture in and irritants out. A deficiency of omega fatty acids may cause various skin conditions.
Fatty fish is one of the best sources of omega-3s. Older adults who eat a lot of fish show less cognitive decline than those who eat a diet high in saturated fats.
Pregnant women need a good supply of omega-3s to ensure normal development of their babies. Omega-3s are especially important for fetal development of the brain and eyes. These essential fatty acids may also prevent depression during pregnancy and the postpartum period.
Foods With Fatty Acids
These eight foods are some of the best sources of healthy fatty acids:
Two of the omega-3 fatty acids, eicosapentaenoic (EPA) and docosahexaenoic (DHA), are known as the” marine fatty acids” because they occur almost exclusively in fish. The best sources are salmon, herring, sardines, and other fatty fish.
2. Flaxseed Oil
Alpha-linolenic acid (ALA) is another essential fatty acid. The recommended amount of ALA ranges from 0.5 to 1.6 grams (g), depending upon age and sex. One tablespoon of flaxseed oil contains over 7g of ALA. To get the full benefit of ALA, it needs to be converted into EPA and DHA, and the body doesn't do that efficiently. Flaxseed oil is good for you, but still not as good as fatty fish.
Olive oil is high in monounsaturated fatty acids, making it a good dietary substitution for unhealthier saturated fat. Extra-virgin olive oil is minimally processed without using chemicals or heat. It is one part of the heart-healthy Mediterranean diet.
4. Chia Seeds
Tiny black chia seeds are rich in omega-3s, and they also contain protein and fiber. Unlike some seeds, they release their nutrients without being crushed.
Walnuts pack a double punch, as they contain both omega-3s and omega-6s. One ounce of walnuts contains about 2.5g of ALA, which is about twice the average recommended daily intake. Still, you should consume walnuts in moderation as they contain about 185 calories per ounce (about seven nuts).
6. Canola Oil
Canola oil is lower in saturated fat than other commonly used cooking oils. One tablespoon of canola oil contains more than 1g of ALA. It is a highly processed oil, but food purists can look for the cold-pressed version.
7. Sunflower Oil
While it has always been considered a source of healthy unsaturated fats, sunflower oil is now available in a high-oleic version, which has a healthier fat profile than olive oil. All types of sunflower oil also contain more Vitamin E than any other oil. Vitamin E is an antioxidant that fights inflammation. It may help protect the body from cardiovascular disease, cancer, eye disorders, and cognitive decline.
Avocados are a good source of monounsaturated oils, and they contain a wide spectrum of other nutrients as well. They are a high-calorie food, with just half an avocado containing about 161 calories.