There are many people that remain under the impression that dietary fat is bad for you. It can be confusing to know how much fat to eat and what kinds are healthy. Our bodies need fat for a number of fundamental health reasons and a century ago, relied on fat during seasonal times of leaner intake as a primary fuel source. That is not the way it goes today in the land of plenty.
However, all fats are not created equal. There are saturated fats, trans fats, monounsaturated fats and polyunsaturated fats. We know that trans fats are the most detrimental to our bodies and should be avoided. Let's start with some background. For more details, see Per Harvard School of Public Health’s paper, “The Nutrition Source Fats and Cholesterol: Out with the Bad, In with the Good“
Monounsaturated fat is a type of fat found in a variety of foods and oils. Studies show that eating foods rich in monounsaturated fats improves blood cholesterol levels, which can decrease your risk of heart disease. Monounsaturated fats may benefit insulin levels and blood sugar control, which can be especially helpful if you have type 2 diabetes. Polyunsaturated fat is a type of fat found mostly in plant-based foods and oils. Evidence shows that eating foods rich in some polyunsaturated fats improves blood cholesterol levels. They may also help decrease the risk of type 2 diabetes. One type of polyunsaturated fat, omega-3 fatty acids, may be especially beneficial to your heart. Omega-3s, found in some types of fatty fish, appear to decrease the risk of coronary artery disease. They may also protect against irregular heartbeats and help lower blood pressure levels.
So, now that you have the basics that we all need good fat in our diet, lets discuss some healthy options to get in our daily servings of good fat.
Omega 3 fatty acid: As mentioned earlier, these poly-unsaturated fats have heart protective properties. But these powerful fats have many other health benefits including anti-inflammatory properties throughout the body, lowering triglyceride levels and assisting with other medical conditions such as depression and ADHD. There are several types of omega-3 fatty acids. Two crucial ones, EPA and DHA , are primarily found in certain fish. Plants like flax contain ALA, an omega-3 fatty acid that is partially converted into DHA and EPA in the body, provided one has the genetic capacity. Algae oil often provides only DHA.
Fish high in DHA and EPA omega-3 fatty acids include anchovies, bluefish, herring, mackerel, salmon (wild has more omega-3s than farmed), sardines, sturgeon, lake trout, and tuna. Many experts recommend eating these fish two to three times a week. Good food sources of ALA, which is converted into omega-3 fatty acids in the body include walnuts, flax and flaxseed oil, canola oil (I recommend only cold pressed or expeller expressed organic canola if you use canola), olive oil, and soybean oil (non GMO soybean oil). Studies show that healthy men, and those who have already suffered a heart attack, can reduce cardiovascular risk by eating nuts regularly, reports the Harvard Men's Health Watch. While foods containing omega-3 fatty acids have health benefits, some, like oils and nuts, can be high in calories, so eat them in moderation. Substitute nuts for chips or cookies, and avoid nuts that are fried in oil, contain cottonseed oil or loaded with salt or sugar. As little as two ounces of nuts a week appears to help lower heart disease risk.
A quick word about fish and metal toxicity: The Environmental Protection Agency (EPA) reports that regular consumption of fish is not a health concern, but it is necessary to understand the risks. The EPA recommends avoiding fish that contain the highest concentrations of mercury, like swordfish, shark, tilefish and king mackerel. Fish with lower traces of mercury are shrimp, tuna, salmon and catfish, and can be safely consumed twice a week. Checking local fish safety advisories for the latest report is the best way to stay informed. This does not mean fish should be avoided, as it should be incorporated at least 3-4 times per week. It is important to know which fishes have higher levels of methylmercury and to avoid those species. So choose cleaner fish options and enjoy the benefits that clean fish can provide. Check out this very informative short video, Mercury: From Source to Seafood.
Coconut oil: The main saturated fat in coconut oil is lauric acid, a medium chain fatty acid. Lauric acid increases levels of good HDL, or high-density lipoprotein, and bad LDL, or low-density lipoprotein, in the blood, but is not thought to negatively affect the overall ratio of the two. Coconut oil has actually been shown to help optimize body weight, which can dramatically reduce your risk of developing type 2 diabetes. Besides weight loss, boosting your metabolic rate will improve your energy, accelerate healing and improve your overall immune function.Because coconut oil is highly saturated, it is not prone to oxidation and remains stable even at high cooking temperatures.
The saturated fatty acids in coconut oil also appear to offer protection against oxidative stress in mitochondria in our cells. Our brains and our hearts have the highest concentration of mitochondria. Coconut oil is considered one of the best fuels for healthy brain function. Coconut oil is nature's richest source of medium chain triglycerides. Coconut oil is a source of medium chain triglycerides (MCT). MCTs don’t have to go through digestion, rather, they get dumped directly into the portal vein as an energy source. Coconut oil is naturally rich in ketone bodies. It increases the levels of Betahydroxybuterate, a ketone body that can also be used as an energy source by the brain. Studies have indicated its benefits for neurological conditions like Parkinson’s Disease.
The takeaway-good fats such as olives, olive oil, nuts, seeds and avocado are heart healthy and assist in blood sugar control and satiety. The serve as wonderful energy sources. I prefer olive oil and coconut oil to cook with and generally avoid canola oil and always avoid cottonseed oil (last I checked rapeseed - the source of canola oil - and cotton were not part of the human diet).
This article was written with the assistance of interns: Diane May from Columbia Masters in Nutrition program and Gail Chen and Jerred Jones from University of Bridgeport Masters in Nutrition program.