However, fat is liberally consumed and highly valued in traditional diets. Traditional fats are nutrient dense and minimally processed. Examples are butter, lard, tallow, cold pressed extra virgin olive oil, nuts and seeds, and fish oils among others.
Today the average US adult consumes an average of 26 pounds of processed vegetable oils a year. These oils are a highly processed product of the food industry and not something you would find in traditional diets. Some vegetable oils come from commodity crops such as corn and soybeans. Other oils are extracted from seeds such as sunflower oil.
Along with processed plant oils, Americans consume high quantities of starches and simple carbs in products such as soda, chips, crackers, cookies, and some fast food. Consuming excess carbohydrates has a big effect on blood levels of triglycerides, which are linked to heart disease.
As we will review in this post, fats are essential for our health with some fats having to come from our diet because our body cannot make them. The key takeaway when choosing dietary sources of fat is to focus on fat quality, to consume it through whole food sources, and to give special attention to plant sources of fat.
WHY FAT IS ESSENTIAL FOR OUR HEALTH
From a physiological perspective:
*Structural function: fat is the major component of our cell membranes (the coating that encloses our cells). Phospholipids and cholesterol are key to regulating membrane fluidity and the movement of molecules across the membrane (e.g. nutrients, waste, gases, hormones).
*Structural and protective functions: fat helps cushion and protect neurological tissues, including the brain, by creating a protective sheath around neurons.
*Message signaling function: Fat is the starting point for building some of our hormones (e.g. estrogen, testosterone).
*Multifaceted functions: Fat is the starting point for building Vitamin D which plays a role in calcium absorption, immunity, brain health, and lung health among others.
*Regulatory function: Regulatory molecules such as prostaglandins, leukotrienes and thromboxanes are fat based.
*Transport function: some fats acts as carrier molecules (e.g. lipoproteins that transport fats in the blood).
*Digestive function: fat is a component of bile, which aids in fat digestion.
From a dietary perspective:
*Fat makes food more flavorful and enjoyable!!
*Fat provides a concentrated energy source. It provides more than twice as much chemical energy as carbohydrates (9 calories per gram of fat vs 4 calories per gram of carbohydrate). Because it is digested slowly, it provides longer lasting energy than carbohydrates, helping us stay satiated longer.
*Fat is needed to absorb fat-soluble vitamins (A, D, E, K). This is why it is important to add some fat when eating a colorful plate of veggies.
*Fat slows down digestion and absorption of sugars, helping with blood sugar management.
TYPES OF FATS AND DIETARY SOURCES
*UNSATURATED FATS with one or more double chemical bonds in their chemical structure. These double bonds create kinks in the fat, which makes the fata liquid at room temperature. Unsaturated fats regulate inflammation in the body, are beneficial for cholesterol levels, and protect nerve cells in the brain and the eyes.
Monounsaturated fats have one single double chemical bond in their structure. Dietary sources of monounsaturated fats include olives and olive oil, avocados, peanuts, sesame seeds, nuts, chicken fat, lard
Polyunsaturated fats have more than one double chemical bond in their structure. They are also known as essential fatty acids because our body can’t make them, we have to get them through our diet.
There are two groups of essential fatty acids: The Omega-3 (double chemical bond in the 3rd position) and the Omega-6 fatty acids (double chemical bond in the 6th position).
- OMEGA-3 ESSENTIAL FATTY ACIDS. They can be found in flaxseeds, chia seeds, walnuts, hemp seeds, and fatty fish (SMASH). There are 3 types of Omega-3 fats: alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). ALA can be converted to EPA and DHA in the body, but the conversion is not always efficient. This is why it is also important to get EPA and DHA directly in the diet. Omega-3 fats are important components of cell membranes. For example, 35% of brain membrane fats contain DHA, 60% of eye photoreceptor membrane fats contain DHA.
- OMEGA-6 ESSENTIAL FATTY ACIDS. They are found in walnuts, almonds, cashews, tofu, hemp seeds, walnuts, sunflower seeds, and eggs. They are highly concentrated in industrially produced meat (animals fed corn and soybeans) and in processed vegetable oils such as corn oil, soybean oil, sunflower oil, and safflower oil.
While both omega-3 and omega-6 fatty acids are essential, there is an ideal healthy ratio for consuming them. This ratio is believed to be a 4:1 omega-6 to omega-3 fats. However, following a Standard American Diet results in a 15:1 to 20:1 omega-6 to omega-3 ratio, which is heavily skewed toward omega-6 fats. Why? This comes from the reliance on fast food and processed foods which are made with vegetable oils high in omega-6 fats (specially soybean oil).
The health consequences of overconsuming omega-6 fats in proportion to omega-3 fats is a chronic proinflammatory state. The more omega-6, the more they engage in pro-inflammatory pathways while blocking omega-3 fats from following an anti-inflammatory pathway. While inflammation is a healthy and appropriate immune response in the face of infections or injury, ongoing chronic inflammation has negative health consequences. Chronic inflammatory diseases include stroke, heart disorders, cancer, obesity, diabetes, and chronic respiratory diseases.
To optimize the omega-6 to omega-3 ratio I recommend switching from corn and soybean oil to extra virgin olive oil, eating omega-3 rich foods, reducing the intake of industrially produced meat lower consumption of seed oils and reducing the intake of fast food and packaged food.
*SATURATED FATS are packed with hydrogens and have no double chemical bonds in their structure. Hence, they form a straight chain without kinks and they are solid at room temperature. For example, butter and coconut oil are high in saturated fat. Saturated fats protect the brain, provide energy for the heart, and support cell membrane structure.
A high consumption of saturated fat along with a low consumption of fiber and antioxidants (colorful plants) is linked to inflammation, high cholesterol, and heart disease.
Animal sources of saturated fat are dairy, bacon, sausage, processed meats, poultry skin, fatty cuts of meat, egg yolks. Plant sources of saturated fats are coconut oil, cacao, and palm oil.
*CHOLESTEROL is a type of fat used to make bile, to make steroid hormones (e.g. cortisol, testosterone, estrogen, DHEA) and to make vitamin D. Cholesterol is also a component of all cell membranes, including brain cells, where it aids with membrane fluidity.
Cholesterol is found in animal products such as eggs, dairy, shellfish, pasture-raised meats, organ meats, and fish. Plants do not contain cholesterol.
Cholesterol is both consumed in the diet (20% of cholesterol levels) and manufactured by the liver (80% of cholesterol levels). Hence, a healthy liver is key for regulating cholesterol. Total cholesterol value alone is not enough to assess cardiovascular risk. It is important to ask your provider for a detailed lipid profile to get a measure of the subtypes of HDL and LDL.
Risk factors associated with increased risk of high blood cholesterol include low fiber intake, high sugar intake, stress, lack of exercise, smoking, high-fat intake when accompanied by nutrient deficiency. Moreover, thyroid function and genetic components affect blood cholesterol levels.
*Smoking or overheating oil causes fat oxidation. Consuming oxidized oils is harmful for the human body. Polyunsaturated fats are most at risk of oxidation due to their unstable double bonds. It is important to cook with high smoking point fats and to eat lots of antioxidant rich foods which can scavenge and neutralize damaging free radicals. I am referring to colorful plants!
*Trans fats, which we have mentioned before in this blog series before, are to be completely avoided. Their consumption is linked to heart disease and changes in the brain. Natural oil contains virtually no trans fats. On the other hand, processed oils that are industrially “solidified” with the purpose of increasing their shelf-life do contain trans fats. These trans fats are used in the making of margarine, shortening, French fries, fast food, some packaged foods and some baked goods. You can identify trans fats by reading the ingredient list and looking for partially hydrogenated oils in the list. This is the telling sign.
3 RECIPES TO HELP YOU BRING HEALTHY FATS INTO YOUR PLATE THIS WEEK
*Strawberry balsamic salad with walnuts
*Turkey wraps with almonds, cucumbers, and blueberries snack box
*Baked walnut crusted salmon
NUTRITION FUN FOR THE KIDDOS
Here are some ideas to add healthy fats to snacks and family friendly meals. Have your child choose a healthy fat to try this week and then decide how to use it to make some delicious food during the week!
*Avocado: make an avocado toast, use it to top scramble eggs, add it to a smoothie.
*Nuts and seeds: use as yogurt toppings, add into a muffin or energy bite recipe, blend it up into a butter, soak overnight to make nondairy milk in the morning.
*Canned sardines or salmon: eat sardines as a snack with cucumbers, mash the salmon with mustard and avocado and use it on toast, crumble the salmon and use it as a topping on pasta, use the salmon to make salmon cakes.
*Full fat unsweetened Greek style yogurt (dairy or alternative): use as a base for a breakfast yogurt bar with fresh fruis and seeds as toppings, add it to a smoothie, spread it on toast with fresh berries or jam, use it as base for a vegetable dip (combine with olive oil, lemon, salt, and pepper).