Dietary fat has made a huge comeback in recent years. Everyone with any sense at all agrees that healthy fats are an essential part of the perfect diet. What still trips many people up is trying to identify what kind of fat is good for you.
Ask a mainstream dietitian and they will swear that saturated fat from animal fat should be replaced with polyunsaturated vegetable oils. Unfortunately, this approach, which came out of the faulty belief that saturated fat caused heart disease, has only made things worse, resulting in skyrocketing obesity rates and an increase in chronic diseases like diabetes.
Thanks to research led by Dr. Artemis Simopoulos, we know that for optimal health, a different approach is necessary. In determining fat intake, we need to focus on eating fat in the right ratios and planning fat intake within the context of the overall diet.
What Are The Different Kinds of Fat?
Most foods don’t have just one type of fat. They are complicated mixtures and will contain different types of fat; however, people typically label them based on whichever type of fat predominates. For example, olive oil is roughly 70 percent monounsaturated fat, 15 percent polyunsaturated fat, and 15 percent saturated fat but we typically label it as monounsaturated fat.
Saturated fat primarily comes from animal products such as fatty cuts of meat, eggs, or dairy. Cooking fats that contain saturated fat include butter, tallow (beef fat), and lard (pig fat). Coconut and other tropical oils also contain saturated fat.
Monounsaturated fat comes from fruit, nuts, and some seeds. Olives, avocados, almonds, pistachios, peanuts, and sesame seeds are examples of foods with a decent amount of monounsaturated fat.
Polyunsaturated fat is made up of omega-3 and omega-6 fats. There are three kinds of omega-3 fat: ALA found in flax oil and some other seeds and nuts, and EPA and DHA, found in fish. Grass-fed dairy and meat also contain some omega-3 fat. EPA and DHA are also present in algae and some wild green plants like purslane.
Omega-6 fats are found in seeds, some nuts, and grain-fed meat and dairy. There are two types of omega-6 fat, LA (found in seeds and nuts) and AA (in animal products). People on a Western diet consume the majority of their omega-6 fat from grain-fed animal products and seed oils, such as corn, sunflower, safflower, cottonseed, and soy bean oil.
An Evolutionary Approach
Studies show that humans evolved eating a diet with close to a 1-to-1 ratio of omega-6 to omega-3 fat. Due to a dramatic change in our food supply over the past 50 years, this ratio has gotten skewed closer to 20-to-1 of omega-6 to omega-3 fat.
In the 1970s, due to the now disproven belief that saturated fat causes heart disease, the USDA came out with dietary guidelines recommending the replacement of saturated fat with vegetable oils such as canola or soybean oil in the hopes that this shift would lower heart disease and reduce obesity. At the same time, there was a large increase in industrially raised cows, chickens, and fish. These animals receive primarily grain-based feed, leading to an increase in omega-6 fat in conventional meat, fish, and dairy products.
The result is that Westerners eat a diet very high in omega-6 fat. This unbalanced ratio is associated with a number of diseases, obesity, and related health problems. Why does this happen?
#1: Increase in Inflammatory Compounds: Eicosanoids
High levels of omega-6 intake lead to production of eicosanoids, which are biologically active compounds that cause inflammation, harming the blood vessels and increasing blood viscosity (how thick your blood is), vasoconstriction, and cell growth. The result is high blood pressure and poor vascular function, negatively impacting cardiovascular function and increasing heart disease risk.
#2: Activation of Brain Reward Centers: Endocannabinoids
A high omega-6 to -3 ratio increases endocannabinoids, which are compounds that affect appetite and energy expenditure. Endocannabinoids activate receptors in the brain, increasing appetite and food intake so that people eat more calories. They also enhance sweet taste and the craving for high-fat, high-sugar foods that are highly palatable. These are the same receptors that are activated in response to THC from marijuana and are the reason that people often get the “munchies” when they are high.
#3: Increase In Fat Cells
The omega-6 fat arachidonic acid (AA) increases the development of new fat cells and the growth of existing fat cells. AA also inhibits uncoupling protein gene expression that is linked with body temperature regulation. When uncoupling proteins are activated, body temperature increases so that you burn more calories—a mechanism that is thought to be one reason diets high in healthy fat are associated with better weight management.
#4: Reduction in Insulin Sensitivity & Other Hunger Hormones
You probably know insulin is a hormone released in response to an increase in blood sugar (from eating carbs) and it allows the body to store energy as fat. When cells become less sensitive to insulin, more insulin is needed to get the same effect, which results in the body spending more time in fat storage mode. It is also associated with increased hunger and food intake, so there is more energy available for the body to store as fat. Omega-6 fats reduce insulin sensitivity but they also act on the central nervous system to alter the hormones that regulate hunger, resulting in people having bigger appetites and eating more calories.
Benefits of A Balanced Ratio
When the omega-3 to -6 ratio is more closely balanced a number of good things happen:
Blood flow increases and the health of blood vessels is improved. For example, when people with high blood pressure took 2 grams of fish oil (supplying omega-3 fats) for a year, systolic blood pressure decreased by 2.7 mmHG and diastolic by 1.3 mmHG.
Fat burning increases because omega-3s also increase the browning of white fat, so that it is more easily burned.
Energy expenditure increases so that the body uses more calories. For example, one study found that fish oil supplementation increased energy expenditure by 51 percent after eating.
Insulin sensitivity and glucose utilization are enhanced so that the body is better able to use energy instead of storing it as body fat.
Hunger management improves due to a decrease in the dysregulation of the endocannabinoid system. Sensitivity to leptin and other hunger-related hormones also increase.
The stress response is more balanced, with lower release of cortisol and less anxiety and depression.
Genetic & Gender Differences
A high intake of omega-6 fat is harmful for everyone, however, certain populations are more adversely affected. Genetically, people with the gene variant known as Halotype D experience an increase in the production of arachidonic acid (AA) from linoleic acid (LA) that is most closely associated with the negative effects of omega-6 fats. About 50 percent of African Americans, 40 percent of Caucasians, and 33 percent of Europeans have halotype D, making a skewed omega-6 to -3 ratio more harmful for these populations.
Gender also impacts how the omega fats are metabolized. With the same diet that is high in omega-6 fat, women experience higher conversion of pro-inflammatory eicosanoid compounds, which have inflammatory and obesity effects. In one recent Danish study, increasing omega-6 fat intake was associated with fat gain and increased waist circumference in women, while the opposite was shown in men.
What Can You Do To Rebalance Your Fat Intake?
The first step is to decrease your omega-6 fat intake and bump up your omega-3s. Start by eliminating seed oils like corn, soy, sunflower, safflower, peanut, etc. Avoid processed foods, which almost uniformly have omega-6 fat added to them. Restaurant meals are often cooked in omega-6 oils, so watch out for this as well.
Try for two servings of wild-caught fatty fish a week and choose grass-fed meat and dairy because these foods will be high in omega-3 fats. Taking fish oil is another option. Just be sure to get a good quality fish oil that is not oxidized (rancid). You can test your fish oil by taking a tablet and chewing it up. It should taste mild and bland, not fishy or nasty.
Once you’ve got the biggest omega-6 offenders covered, you want to increase healthy nut and seeds. Walnuts, almonds, flax, sesame, and chia seeds are all good sources of the omega-3 fat ALA. Soak nuts and seeds to soften them so they are digestible. To avoid them becoming rancid, buy small quantities, keeping them in the fridge in an air-tight container.
Eating green vegetables and dark colored fruits, such as kale, chard, broccoli, berries, plums, etc., is also important because these foods will provide antioxidants to help eradicate inflammation and protect cells from the effect of polyunsaturated fat that has been oxidized or damaged.
Include other healthy fats so that you get a wide range of nutrients. Be sure to include some saturated fat from butter, meat, or coconut oil so that you get cholesterol necessary for synthesizing steroid hormones.
When cooking, choose fats that are not easily damaged by heat. Never cook with polyunsaturated fats. Olive oil can be used for lower temperatures, but opt for oils that are mostly saturated when grilling or using high temps. Coconut oil and butter are great options.
Beans (great norther, garbanzo, and black beans) provide insoluble fiber that get broken down into short chain fatty acids such as butyric and propionic acid, which can improve the health of your digestive tract. They also contain a large quantity of alpha-lipoic, which is a protective component of omega-3s.
Finally, use the principles of quality and variety. Always choose foods in their most natural state. This is just as important when choosing protein and carbohydrate sources as it is for fat. Protein should come from meat, fish, eggs, dairy, nuts, and beans. Carbs should be vegetables, fruit, and boiled grains. Include a wide variety of foods in your diet to get a diverse nutritional profile and avoid food intolerances.