Every day we read more about the fats in our diets: transfats, saturated and unsaturated fats, fatty acids, good fat, bad fat—the list goes on and arguments for and against seem to change with regularity. What ARE these molecules that are a part of our everyday diet? Where do we find them and what do they do? Are they helpful or harmful in our quest to reach or maintain optimal health?
We need fat! Not all fat is bad; in fact some are actually very good for us and promote healthy brains, hearts, nerves, and skin. Fat is a source of energy, transports the fat soluble vitamins A, D, E, and K from food into your cells, provides insulation and protection for internal organs, and helps to build cell membranes (keeping all organs functioning well).
At nine calories per gram, fat has over twice the calories as proteins and carbohydrates, which have four calories per gram, so we must watch the total intake to avoid becoming overweight. Too much fat can cause obesity, itself a risk factor for numerous diseases. We are aware of the connection between illness and fat intake. Knowing the good versus the bad fats is the first step in lowering the risk of heart and vascular disease, obesity, diabetes and other diseases related to a high “bad fat” diet.
Dietary cholesterol is found in eggs, butter, lard, meats and poultry. Current research is showing that dietary cholesterol intake is not as critical as we once thought but those foods can still contribute to issues of obesity so we should still limit intake to 300 mg per day. Our bodies produce cholesterol and the amount is thought to be determined by our genetics.
Saturated fats contribute to higher cholesterol levels and are found in beef, pork, butter, cheese, ice cream and other whole milk products. Foods from plants, such as coconut and palm oils, and cocoa butter are also saturated fats. Eating too many saturated fats increases your body’s production of LDL, low density lipoprotein, or “bad” cholesterol. The American Heart Association recommends limiting saturated fats to about 8% of total daily calories consumed.
Unsaturated fats are monounsaturated or polyunsaturated. These fats are found mostly in plant oils. Canola, olive, peanut, and avocado are monounsaturated. Soy, corn, almond, walnut, many seeds, and fish oils are polyunsaturated. These “good fats” may actually help to lower blood cholesterol.
Omega 3 fatty acids are found in fish (mostly salmon, herring, and mackerel), flaxseed and walnuts. They can lower triglycerides (another type of fat found in your blood) and research has suggested that Omega 3s can lower blood pressure and help maintain a healthy heart. But some studies have shown a link between Omega 3 supplements and an irregular heart rate, so before starting any supplements it is important to consult your health care provider.
“Trans fats,” trans fatty acids (TFA), are on everyone’s radar and the worst fats to eat, though often found in the tastiest foods. When foods are processed, fats are sometimes hydrogenated. Hydrogen is added to solidify oils and to lengthen the shelf life of foods. The most recognized are margarine and shortening products. Fully hydrogenated oils are labeled as such and are like saturated fats. Partially hydrogenated oils have been shown to be unsafe in that they significantly increase the risk of cardiovascular disease and diabetes. The Food and Drug Administration required that partially hydrogenated oils (the main source of artificial trans fats) be listed on nutritional labels in January 2006 and in 2015 set the goal of eliminating them from processed foods in 2019. This was extended in 2019 and then January 2021. The amount of partially hydrogenated trans fats in foods has declined, but they are still found in some products such as non dairy coffee creamers, shortenings and baked and fried foods due to certain ban exemptions.
TFAs are found in snack foods, processed foods, cookies and snack cakes. (Sorry to say, Oreos and Twinkies are NOT healthy snacks.) Fast foods are notoriously high in TFAs. Small amounts are found naturally in some animal products such as beef and pork and in the butterfat in mild products but most are the end results of the hydrogenation of oils. These TFAs are harmful because they can raise LDL (bad) cholesterol and lower the HDL (good) cholesterol and this combination increases the risk of heart disease.
We can choose a healthy yet tasty diet. No more than 25% to 30% of our total calories should be from fats. Almonds and walnuts are a better snack than potato chips. Add avocado slices to sandwiches rather than mayonnaise or cheese slices. Sunflower seeds instead of buttery croutons and bacon are a great salad topper. Eat more fish, especially salmon and mackerel.
An overall increase in vegetables, whole grains, healthy fats and lean protein will likely improve health. Reading labels is important and will make you more aware of what you are eating!
Mia Smitt is a nurse practitioner with a specialty in family practice. She recently retired and settled in Tucson after two-and-a-half years living on a 40-foot sailboat exploring the world. She is originally from San Francisco and has lived in eight states and 11 cities in her adult life. She has been married to her husband Erik for 47 years and has two sons, two grandsons locally, and a granddaughter due in November.