Difference between good and bad fat

Monday October 26 2020

Sometimes, it is just good to be fat. PHOTO/COURTESY

By Dr Paul Kasenene

Although I have been advised to cut fat from my diet, I know that some fats are needed in the body. Please let me know which fats I can safely consume. Nancy

Dear Nancy, 
To simplify this, we can broadly categorise fats into two types; saturated and unsaturated fats. Saturated fats are solid or easily solidify at room temperature, while unsaturated fats are mostly liquid. There is a general belief that saturated fats are bad and cause heart disease and unsaturated fats are better. However, this is too general and misleading.

Not all saturated fats are bad. For example, coconut oil and ghee are high in a type of saturated fat that is beneficial to health because they reduce inflammation. On the other hand, saturated fat from animals reared to grow rapidly and fatten can be linked to heart problems, if we eat too much.

However, the worst type of saturated fat to always avoid are trans fats or hydrogenated fats found in margarine, vegetable shortening and packed baked goods such as biscuits and cookies because these block blood vessels and increase risk for clots, strokes and heart attacks.

There are also different types of unsaturated fats. The best are the monounsaturated fats that are found in avocado, olives, almonds, cashews, chia and sesame seeds, as well as oils such as avocado and extra virgin olive oil. These help maintain healthy cholesterol levels, reduce body fat and help with weight loss. Eat foods high in these often. 

Another type are the polyunsaturated fats. There are many of these, but the most significant are omega-3 and omega-6 fats. Neither are bad. Omega-3 fats reduce inflammation and reduce blood clotting, while Omega-6 fats promote inflammation and blood clotting.


Omega 6 fats are not bad because inflammation is important as a response to injury and clotting is sometimes useful.

However, what is important is the ratio of these fats in food. It is best to eat foods with a higher ratio of omega-3 to omega-6 fats. Foods high in omega-3 fats and low in omega-6 fats that we should eat often include chia and flax seeds, nuts such as walnuts, fish such as salmon, as well as fish oils such as cod liver oil.

These remove fat from blood vessels and reduce risk for blood clots. But some oils such as sunflower, peanut and corn oils are too high in omega-6 fats and, therefore, increase the risk for chronic inflammation and abnormal blood clotting. Please avoid foods that have a high risk of omega-6 to omega-3 fats, even if they are plant-based.