We hear all the time about the importance of healthy fats. Beyond the general consensus that fat is an essential part of a well-rounded diet, there is a lot of confusion about what constitutes a “healthy fat.”
You’ve probably heard the following public health statements:
“Replace dangerous saturated fat with heart-healthy unsaturated fats like vegetable oils.”
“Use soybean oil instead of coconut oil to lower cholesterol levels and reduce cardiovascular disease.”
“Choose low- or non-fat dairy products to lower your risk of heart disease and obesity.”
Unfortunately, all of these recommendations are based on faulty science and are a classic example of the confusion about what sources of fat you should be eating.
For example, diets high in soybean oil are associated with insulin resistance and obesity. In fact, soybean oil consumption has increased more than 1,000 times from 1909 to the present day and is thought to be one of the primary foods driving obesity in the Western world.
Non-fat dairy products remove many of the healthiest components of dairy foods, such as the fat-soluble vitamins A, D, E, and K, while changing the way the amino acids and carbohydrates are digested, negatively affective metabolic function.
Finally, replacing saturated fat (butter or lard) with vegetable oils (corn or canola oil) supplies an excess of a certain kind of polyunsaturated fatty acids called omega-6 fats, which contribute to inflammation and obesity when they are consumed in large quantities.
To avoid further confusion and guide you in your quest for the healthiest diet, this article will explain the pros and cons of different fat sources.
Dietary fats are typically classified as one of the following:
Polyunsaturated Fat is made up of omega-3 and omega-6 fats, which come from both plants and animals. There are three kinds of omega-3 fat: ALA found in flax oil and some other seeds and nuts, and EPA and DHA, found in fish. Grass-fed dairy and meat also contain some omega-3 fat. Vegetarian sources of EPA and DHA are algae and some wild green plants like purslane.
Omega-6 fat are found in seeds, some nuts, and grain-fed meat and dairy. There are two types of omega-6 fat, LA (found in seeds and nuts) and AA (in animal products). People on a Western diet consume most of their omega-6 fat from grain-fed animal products and seed oils (often called vegetable oils), such as corn, sunflower, safflower, cottonseed, and soybean oil.
Is It Healthy?
Everyone agrees that omega-3 fat is healthy. EPA and DHA are the most favored fats, having numerous beneficial effects including improved blood vessel function, better insulin sensitivity, and less inflammation. They are also linked to better mood, improved appetite regulation, and better ability to handle stress. EPA and DHA also appear to be protective against obesity.
ALA is also associated with many health benefits and it can be turned into EPA and DHA in the body, however the conversion rate is low, making it critical that everyone include EPA and DHA-containing foods in their diet.
Omega-6 fats can be confusing. They are essential for optimal health; however, if consumed in too high a quantity, they can be harmful. Studies show that humans evolved eating a diet with close to a 1-to-1 ratio of omega-6 to omega-3 fat. Due to a dramatic change in our food supply over the past 50 years, this ratio has gotten skewed closer to 20-to-1 of omega-6 to omega-3 fat.
This is a problem because omega-3 and omega-6 fat compete for certain enzymes that allow them to function in the body. With too much omega-6 fat, the omega-3 fat can’t have its protective effect. Then there’s the fact that most Westerners get almost zero omega-3 fat in their diet but large quantities of omega-6 fat. A safe approach is to actively avoid foods that are high in omega-6 fat in favor of other fat sources.
Saturated Fat comes primarily from animal products such as fatty cuts of meat, eggs, or dairy. Cooking fats that contain saturated fat include butter, tallow (beef fat), and lard (pig fat). Coconut and other tropical oils also contain saturated fat.
Is It Healthy?
There is a widespread, deeply ingrained misconception that saturated fat is bad for you due to the disproven theory that it causes heart disease. Although it is true that a high intake of saturated fat from certain foods like butter can raise LDL cholesterol, this doesn’t mean that it should be uniformly classified as an unhealthy fat.
In fact, we need saturated fat because it provides cholesterol for the body to synthesize steroid hormones like testosterone. Foods that contain saturated fat provide the fat-soluble vitamins A, D, E, and K in a form that is easily digested and used by the body.
Additionally, mitochondria, which, as you’ll remember from elementary biology, are the energy factories in your body, function better when their fatty membranes are composed of saturated fat. When mitochondria have saturated fat in their membranes they are less susceptible to damage and produce fewer reactive oxygen species that bounce around and harm cells and DNA.
Another good thing about saturated fat is that it is not easily damaged by high temperatures, making it great for cooking. Oils that are high in polyunsaturated fat are easily oxidized and should not be used for cooking.
Monounsaturated Fat comes from plants. Fruits (olives and avocados), nuts, and some seeds all contain monounsaturated fat. The omega-7 and omega-9 fats are monounsaturated fats. The number 7 or 9 refers to the location of the double bonds on the fatty acid molecule. Oleic acid is the most common omega-9 fat and it is best known for being present in olive oil. Palmitoleic acid is the most common omega-7 fat and it is found in macadamia nuts and sea buckthorn berries.
Is It Healthy?
Pretty much everyone agrees that monounsaturated fat is healthy. These fats have many beneficial effects, improving function of mitochondria and insulin action, while also increasing glycemic control for lower diabetes risk. Foods high in monounsaturated fat have been found to lower triglycerides, which are a marker of the amount of fat in the blood and a primary predictor of heart disease.
Many monounsaturated fats are also packed with antioxidants that counter free radical damage and lower inflammation. They have anti-cancer effects and can lower inflammation in the joints. Association studies show that diets higher in monounsaturated fat, such as the traditional Mediterranean diet, are useful for weight management and may prevent obesity. Recent studies indicate supplementation with omega-7 fat may improve metabolism and promote fat loss.
Hydrogenated Fat (also known as man-made trans fat) is produced when a hydrogen atom is added to an omega-6 polyunsaturated fat. Hydrogenated fats are solid at room temperature and they are used in baked goods to improve the texture and extend the shelf life. Hydrogenated oils are also used to make margarine and are added to peanut butter so that the oil doesn’t separate out. Restaurants and fast food chains use hydrogenated oils because they stand up better to heat and don’t go rancid quickly.
The most common hydrogenated fats are made from cottonseed, palm, soy, and corn. The fact that palm and cottonseed oils have historically been hydrogenated is one reason these fats have a bad rap even if they are not hydrogenated.
Is It Healthy?
Hydrogenated fats are difficult for the body to metabolize and they can’t be excreted in the normal fashion. Instead, hydrogenated fats remain circulating in the blood, becoming oxidized (or damaged) and contributing to increased risk of heart disease, diabetes, and cancer. Hydrogenated fat consumption is also linked to brain deterioration, Alzheimer’s, depression, obesity, and increased bodily pain.
Hydrogenated fat is so bad that the FDA made a move to ban it from the U.S. food supply. Under the rule, food manufacturers have until 2018 to remove hydrogenated fats. There are loopholes to the ban: Companies can petition the FDA to use hydrogenated oils in their products, so it’s critical that you always read food labels and avoid hydrogenated or partially hydrogenated oils.
Natural Trans Fat is produced during the digestion process by ruminant animals. Naturally occurring trans fats are produced in cows and other animals that chew their cud when the stomach bacteria add a hydrogen ion to fatty acids. An example of a natural trans fat is conjugated linoleic acid (CLA), which is present in dairy and meat from pasture-raised animals
Is It Healthy?
Studies show that consumption of fat containing CLA has a number of health benefits. CLA is thought to have anti-cancer effects, improve immune function, enhance insulin sensitivity, and promote glucose tolerance. CLA is also known to decrease inflammation and may be useful for fat loss or weight management because it triggers thermogenesis or the burning or calories. Simply, CLA stimulates something known as the uncoupling protein genes, which raise body temperature so that you burn more calories daily.
Practical Advice For Including Fat In Your Diet
Now that you have a general overview of what we mean when we talk about healthy versus harmful fats, we need some practical advice for including fat in the diet.
First, it’s important to realize that most foods don’t contain just one type of fat. They are complicated mixtures and will contain several different kinds of fat; however, people typically label them based on whichever type of fat predominates.
For example, olive oil is roughly 70 percent monounsaturated fat, 15 percent polyunsaturated fat, and 15 percent saturated fat but we typically label it as monounsaturated. Remember that olives and olive oil are a great source of the omega-9 fatty acid, oleic fat.
Another example is peanut oil, which is 20 percent saturated fat, 32 percent polyunsaturated omega-6 fat, and 48 percent monounsaturated, but it’s often identified as a polyunsaturated fat that should be avoided due to its higher concentration of omega-6 fats.
Then there are the animal-based fats like butter, lard and tallow. Although these are typically categorized as saturated fat, butter is 62 percent saturated, whereas lard is only 39 percent saturated and tallow is 41 percent saturated with the remaining fat being monounsaturated.
Second, studies suggest that the key to health is to choose fats in their most natural form. This means you’re better off eating fats in nuts, seeds, fatty cuts of meat, whole fat dairy, eggs, avocado, olives, and fish than in processed foods.
Third, fat intake needs to be balanced. You want a near equal intake of omega-3 and omega-6 fats, so it’s a smart idea to regularly include fish and grass-fed meat and dairy along with moderate intake of a variety of nuts. Seeds can also be included in small quantities. Saturated fat from butter, coconut oil, and other tropical oils can be included in reasonable amounts to supply vitamins and cholesterol for optimal hormone production.
When cooking, choose heat-stable saturated fats over plant-based cooking oils (canola, vegetable, soybean, corn, peanut oil) to avoid oxidation and lower your intake of omega-6 fats. Finally, avoid man-made trans fats and processed foods since these provide an abundance of unhealthy fats from omega-6 fats.
Finally, context is important. Diets high in refined carbs, junk food, or processed protein aren’t going to be healthy even if you focus on eating healthy fats. Choose foods in their most natural form and be sure to eat a wide range of vegetables and high-quality protein with your healthy fat.