Fats have gotten a pretty bad reputation. Lots of medical conditions, from heart disease to diabetes, are blamed at least partially on too much dietary fat – or fats that are consumed. In many cases, fats are one of the culprits behind these medical conditions. However, rarely does anyone ever mention that not only are some fats beneficial, but in fact the body can’t function without at least some dietary fats.
Fat performs several different jobs in the body.
The most basic purpose of bodily fat is as a backup source of energy. The body uses calories as fuel for energy. Normally, carbohydrates are converted into energy after eating. However, if the body needs more energy than is being taken in, it can draw on stored fat. Fat is a concentrated source of calories, with more than twice the calories per gram as carbs or protein.
Just like with everything else in life, too much of a good thing can be a bad thing, and there is definitely such a thing as too much fat. Excess calories are converted and stored as fat. When this happens on a regular basis, it leads to weight gain and, potentially, becoming overweight or obese. However, having too little fat can be detrimental, too. Brain development, blood clotting, and inflammation control all require fat.
Additionally, fat acts as an insulator. Stored fat cells help the body maintain its core body temperature. Fat can even help protect the body by surrounding vital organs and acting like padding, guarding organs from sudden movements or impacts.
Another extremely important function of fat is vitamin absorption. Some nutrients, including vitamins A, D, E, and K, are fat-soluble, meaning the body can’t absorb them properly without some fat. Having too little fat can detrimentally affect hair and nail health and even contribute to malnutrition.
There are multiple different types of dietary fats.
Dietary fats can be categorized into three groups: saturated, unsaturated, and trans. Saturated fats are from animal foods, such as meats, eggs, and dairy. Additionally, tropical oils like coconut, cocoa, and palm oil contain saturated fat.
Unsaturated fats can be broken into two subcategories, polyunsaturated and monounsaturated. Monounsaturated fat is found in avocado, nuts, and some vegetable oils, such as canola, olive, and peanut oils. Polyunsaturated fats include sources of omega-3 fatty acids and omega-6 fatty acids. Omega-3 fatty acids are derived from fatty fish and shellfish, as well as from plant sources like walnuts, flaxseed, or some oils. Omega-6 fatty acids are found in liquid vegetable oils like soybean oil, safflower oil, or corn oil.
Trans fats are fats that have been altered so they’re hydrogenated. This allows these fats to increase the shelf life of foods that contain fats, such as packaged snacks, cookies, margarine, or chips.
Common nutritional guidelines suggest a diet that favors unsaturated fats over saturated or trans fats.
Saturated and trans fats are thought to increase the risk of heart disease and stroke. Additionally, these types of fats are inflammatory, meaning that they encourage inflammation in the body and can potentially increase pain from inflammation.
Polyunsaturated and monounsaturated fats are believed to yield numerous health benefits. These healthy fats can potentially lower the risk of heart disease and stroke, lower bad cholesterol while increasing good cholesterol, and help control or prevent diabetes.
Sources of healthy fats include:
- Nuts and seeds
- Flaxseed oil
- Hemp oil
- Fish and fish oil
- Coconut oil
Researchers began encouraging individuals to reduce the unhealthy fats (saturated and trans) while increasing healthy fats (unsaturated fats) in the 1970s and 1980s. This advice has been taken seriously. Even the American Heart Association recommends watching which types of fats are consumed. Recently, though, the methods used to reach this advice have come under scrutiny.
New studies are being conducted to examine the traditional guidelines about unhealthy and healthy fats.
Researchers have unearthed and analyzed the original studies upon which the fat intake guidelines were based. The studies were heavily flawed, suggesting that the fat intake guidelines may be just as flawed. However, this doesn’t necessarily mean that the guidelines are wrong – simply that the evidence was lacking up until now. New studies are being carried out to evaluate which fats are indeed healthy.
For example, a study from the University of Missouri reevaluated the inflammatory properties of different fats. Vegetable oils have been considered anti-inflammatory in the past. While no anti-inflammatory properties were proven or disproven, it was confirmed that fats from vegetable oils do not cause inflammation. This means that cooking with vegetable oils, instead of animal fats, is a good idea for anyone with a chronic condition.
At the University of Finland, a recent study found that simply reducing the amount of saturated fats in the diet has no real impact on the risk of heart disease. However, this study also found that replacing saturated fat with polyunsaturated fat reduced the risk of heart disease. In fact, benefits were also seen when the polyunsaturated fat was replacing trans fats or carbohydrates. This suggests that the traditional guideline concerning polyunsaturated fat as a healthy fat may, indeed, be true.
Additionally, an article originally published in the British Medical Journal noted an interesting observation:
“A recent analysis of published trial data shows that replacing saturated fats and trans fatty acids with omega 6 fatty acids, without a corresponding rise in omega 3 fatty acids, seems to increase the risk of death from coronary heart and cardiovascular diseases.”
While all this information may seem at time contradictory, overall it suggests a diet that favors variety and moderation. As WebMD explains:
“The best way to prevent heart disease may be to eat more whole, unprocessed foods. So eat fish, beans, fruits, vegetables, brown rice, nuts, seeds, vegetable oils and olive oils, and even some animal products like yogurt and high-quality meat and cheese. “
What healthy fats do you eat on a regular basis?
Image by Aoife Mac via Flickr