We’ve come a long way, baby ... in what we understand about fat and its role in our overall and cardiovascular health.
However conflicting research findings over the last 30 years might leave us confused as to the current recommendations about how much – and what kinds – of fat to include in our diets. It’s difficult to separate the “good fats” from the “bad fats.”
Fats: Angels or Devils?
Even though we don’t think of our foods as combinations of chemicals, the tasty morsels we consume are essentially combinations of carbohydrates, proteins and fats and other components. The chemical structure of each food component determines what our bodies do with it. Proteins are critical to body structures such as hormones, bones and muscles, while carbohydrates serve primarily as an energy source. Fats are used for energy, but also can act as chemical messengers in some of our metabolic and inflammatory pathways.
Fats are categorized by their various chemical structures: saturated (SFA), monounsaturated (MUFA) and polyunsaturated (PUFA). These categories simply reflect the number of double bonds in the carbon chain and determine how the fat acts in our body.
The chemical structures gives each fat its typical flavor, aroma and food stability characteristics. For example, saturated fats are very stable even at room temperature (butter and lard) while the unsaturated fats (safflower and olive oils) can spoil more easily if not refrigerated.
Most trans fats are manmade during processing of polyunsaturated fats when they are processed into shelf-stable convenience foods.
The chemistry of these fats tempts us to label them as “healthy” or “unhealthy.” In reality, most foods we consume are a combination of the different types of fats, and the research around the health risks and benefits of each type is confusing at best.
In general, we have associated animal products with saturated fats and plant products with unsaturated fats. Both saturated fats and trans fats continue to be considered “unhealthy” fats as they have been shown to increase LDL (bad cholesterol) and be more strongly associated with the risk cardiovascular disease and some types of cancer.
Past and Present
Common advice in the 1960s and ’70s was to decrease saturated fat intake and limit overall fat in the diet to 30 percent of the calories, in favor of a higher carbohydrate diet. This advice was apparently based on limited epidemiological studies concerning the role of various fats in the diet.
Americans achieved these recommended changes in fat intake, yet obesity and lipid issues are still prevalent. Given the rise in obesity despite achieving a lower-fat diet, recently the role of carbohydrates – especially as sugars – in the diet has come under fire.
While many studies still support a reasonable limit on the consumption of saturated fats, the role of overall fat in the diet remains somewhat controversial. With the research showing that some fats our beneficial to our health, low fat diets have fallen out of fashion in favor of a message of moderation and balance.
The current Dietary Guidelines for Americans from the National Academy of Science and Institute of Medicine still recommend choosing fewer foods with saturated and trans fats and consuming more monounsaturated fats and polyunsaturated fats, as well as more plant-based foods. It also recommends limiting fats to 20-35 percent of your total caloric intake.
Fats in Your Food
With these recommendations, consumers are eager to learn how “healthy fats” can help them avoid disease.
Polyunsaturated fats seem to have consistently weathered the research as fats that have a positive association with health. They have been shown to improved HDL (good cholesterol) and decrease LDL, both desirable influences.
Omega-3 fatty acids are part of the polyunsaturated class and are strongly touted for their anti-inflammatory and health-promoting effects.
Omega-6 fatty acids are also essential, but are sometimes associated with more inflammation and some negative health effects.
The optimal balance between Omega-3 and Omega-6 chemistries is a current topic of science debate.
The USDA recommends eating a 4-ounce portion of seafood – fatty fish such as salmon, herring or mackerel – twice a week, as these contain high levels of Omega-3s.
To improve the polyunsaturated and monounsaturated fats in your diet, replace high-fat animal products and highly-processed foods with nuts, seeds and oils. Simple ideas include:
• Adding walnuts to your morning oatmeal or your trail mix snack, • Including some olives and sunflower seeds on your salads, • Mixing avocado as part of your salsa, • Grinding chia or flax seed into a morning smoothie in place of anything sugary, • Eating 4 ounces of fatty fish at least two times per week, • Using only lean meats and low fat dairy products, and • Avoiding highly processed foods.
Dr. Jackie Buell; a registered dietician, certified sports dietician and certified athletic trainer; is the director for Sports Nutrition in the Department of Sports Medicine at The Ohio State University Wexner Medical Center and a contributing writer. Feedback welcome at laurand@cityscenemediagroup.com.
Garden Pasta Salad
Ingredients:
2 cups whole-wheat rotini (6 ounces) 1/3 cup reduced fat mayonnaise 1/3 cup low-fat plain yogurt 2 Tbsp. extra virgin olive oil 1 Tbsp. red-wine vinegar or lemon juice 1 clove garlic, minced 1/8 tsp. salt freshly ground pepper, to taste 1 cup cherry or grape tomatoes, halved 1 cup diced yellow or red bell pepper (1 small) 1 cup grated carrots (2-4 carrots) ½ cup chopped scallions (4 scallions) ½ cup chopped pitted Kalamata olives 1/3 cup slivered fresh basil
Preparation:
Bring a large pot of lightly salted water to a boil. Cook pasta, stirring occasionally, until just tender, 8 to 10 minutes, or according to package directions. Drain and refresh under cold running water.
Whisk mayonnaise, yogurt, oil, vinegar (or lemon juice), garlic, salt and pepper in a large bowl until smooth. Add the pasta and toss to coat. Add tomatoes, bell pepper, carrots, scallions, olives and basil; toss to coat well. Makes six servings. Each one-cup serving has approximately 209 calories and 9.4 grams of fat – 1.4g of saturated fat, 3g polyunsaturated fat, and 5g monounsaturated fat.
