What are fats?
Fats are organic molecules made up of carbon and hydrogen elements joined together in long groups called hydrocarbons. The simplest unit of fat is the fatty acid. Fatty acids are essentially like chains consisting of links. The links are made of carbon atoms. Simple chains of carbon atoms with hydrogen atoms added to the chain. Each carbon atom has the capacity to attach 4 other atoms (adjacent carbons plus two hydrogen atoms). They can be short, medium, or long, depending on the number of links that they contain. Regardless of how long they are, they have another important feature – their degree of saturation. Based on the level of saturation (the number of hydrogens associated with each carbon along the hydrocarbon chain) there are saturated fatty acids and unsaturated fatty acids.
Saturated fats are solid at room temperature, and unsaturated fats are liquid at room temperature. When liquid fats like vegetable oils are turned into solid fats through a process called hydrogenation, they become trans fats.
Fatty acids can be joined together to form what are called triglycerides. As the name implies, three fatty acids join together with a glycerol molecule to make up a triglyceride. Triglycerides are the major form of fat in the diet, and the major storage form of fat found in the body.
Note: Trans fats are created through hydrogenation and are quite dangerous. A diet high in trans fats has been associated with a higher risk of Alzheimer’s disease and lymphoma, suppression of the excretion of bile acids, increased liver cholesterol synthesis, competition for essential fat uptake, and exaggerated essential fatty acid deficiency. Even a single meal with a high trans-fat content can decrease the function and elasticity of blood vessels, which can contribute to the progression of heart disease.
Fat – what does it do?
The primary function of fat is to provide energy to the body (next to carbs, and ketone bodies). Fats are a ready energy source, contributing 9 calories for every gram used. That is potential energy we are carrying, both from dietary intake and in the stored fat of our body. This stored fat gives the body the curves and can be used for fuel during times of reduced food intake.
Nearly 60% of the human brain is made up of fat, specifically DHA (a type of omega-3 fat), and as much as 25% of the body-s cholesterol is located in the brain. Our body absolutely needs fat to function and thrive. It needs cholesterol and healthy fat to make hormones and support nerve and a healthy immune system.
It needs fat for fuel, to absorb other nutrients, to help regulate inflammation, movement, and blood clotting, and to make up the membranes that surround the cells (which are essential for cellular development and carrying various messages through our body quickly via hormones) as well as the sheaths that cover nerves. Fats are important for cellular health, and unlike carbohydrates and protein, they also provide our bodies with a layer of protection, protecting our organs from trauma and cold, and also helping keep a normal body core temperature.
Every body cell and thus every tissue and organ is dependent on lipids in the body for its health. Fats also help us absorb important fat-soluble vitamins such as vitamins A, D, E, and K that keep our brains, cells, hormones, tissues, hair, skin, and nails healthy. By assisting in vitamin D absorption, they also help calcium get into the body, especially in the bones and teeth. Fats also help in manufacturing the important hormone-like prostaglandins.
Here is a list of the many functions and benefits of fats:
- Nutrient absorption (extremely important for absorbing fat-soluble nutrients- Vitamins A, D, E, K, and carotenoids)
- Needed for building cell membranes and myelin sheaths
- Lower the risk for heart disease (by improving cholesterol and triglycerides)
- Brain function (and development in infants, children, and teens). Good for mood, memory, and concentration
- Provide insulation and “protection” to the organs; good for body temperature
- Balance blood sugar
- Help to control blood pressure
- Necessary for blood clotting, muscle contractions, and immune function (support white blood cell activity)
- Needed for the right absorption of proteins
- Increase satiety (along with fiber and protein)
- Healthy bones, liver, hormones, hair, and skin
Signs that you need more fat:
How do you know that you need more fat in your diet? Some of the following symptoms may indicate that you need higher overall fat consumption or maybe you need to regulate the ratio of the consumed fats:
- Trouble concentrating
- Dry, itchy, or flaky skin
- Dry, brittle hair
- Always feeling cold, even when it’s warm (could also be a thyroid problem)
- Hunger or not feeling full and satisfied from meals
- Menstrual cycle irregularities
- Hormone imbalances
- Nutrient deficiencies (specifically fat-soluble vitamins- A, D, E, and K)
- Low energy; always feeling tired
- Poor mood (angry, upset, depressed, etc.- see your doctor for proper diagnosis)
- Low HDL (good) cholesterol
The official definition of saturated fat is any fatty acid with no double bonds present between the carbon molecules. Saturated fats are saturated with hydrogen molecules and contain only single bonds between carbon molecules.
This saturation of hydrogen molecules results in saturated fats being solid at room temperature, unlike unsaturated fats, such as olive oil, which tend to be liquid at room temperature.
Saturated fats are the easiest of all the fatty acids to break down in the body, thus they are critical to healthy function of the human body.
Saturated fats from processed meats and dairy can raise harmful LDL cholesterol. However, a lot of the studies that have linked saturated fat to heart disease have actually been quite controversial. Research conducted in the second half of 1900s led to the diet-heart hypothesis, which concludes that dietary saturated fat raises blood cholesterol levels and thus increases the risk of heart disease. However, we should not forget that saturated fats play essential structural roles in the body, and specific saturated fatty acids have specific benefits to energy metabolism, immunity, intestinal health and metabolic health. It is highly important to focus on the quality of these fats and on their sources. Saturated fat from natural, god quality whole foods is way different than that found in processed, industrial foods. Choosing minimally processed foods whenever possible and keeping your intake of saturated fats in moderation is key to maximizing potential benefits while preventing adverse effects on health.
Health benefits of saturated fats
Despite their reputation as an unhealthy form of fat, saturated fatty acids are actually highly important to overall health. They form the foundation of the cell membranes in the body, and also help control which substances are able to flow in and out. They contribute to stronger bones, especially in women, and improved brain, lung, and liver health. Some saturated fats have positive associations with immune health, supporting the function of white blood cells.
They also may have an impact on cholesterol levels. In particular, saturated fat has been shown to increase levels of high-density lipoprotein (HDL) cholesterol, also known as the “good” cholesterol that moves through the blood vessels removing plaque build-up from arteries. This can be especially beneficial when it comes to heart health and prevention of heart-related problems.
Saturated fats can potentially protect against some neurological disorders. It has been shown that these fats are beneficial against stroke (stroke could happen when blood flow to the brain is suddenly cut off).
Here are some of the benefits of saturated fats:
- Increasing the beneficial (HDL) cholesterol (bad LDL cholesterol is raised as well, but it’s wrong to ignore the fact that HDL receives a boost) while converting LDL from small, dangerous particles into large, mostly harmless ones
- Bone health- in order to properly absorb calcium, our bones require a degree of saturated fat
- Hormone production
- They form the foundation of cell membranes (they need to be at least 50% for optimal function)
- May reduce risk of stroke
- Boosts brain health
- Great for high-heat cooking. Saturated fats tend to have a higher smoke point than unsaturated fatty acids like vegetable oils, which can break down and oxidize when exposed to high temperature
- Promote the absorption of fat-soluble nutrients. They are associated with nutrients in whole foods. For example, butter contains valuable fat-soluble vitamins and is also rich in saturated fat.
Where to find them:
Typically, animal products contain high amounts of saturated fatty acids. Here are some of the most common saturated fat examples:
- Poultry with the skin
- Coconut (oil, butter, meat)
- Palm oil
Other foods like processed meat, deep-fried foods, baked goods, and convenience meals may also contain high amounts of saturated fatty acids, along with other types of fat like trans-fat. The consumption of foods should be avoided.
How much to consume:
Public health agencies like the World Health Organization and the USDA recommend limiting intake of saturated fat per day to less than 10% of total calories. This means that on a standard 2,000 calorie diet you should be eating no more than 22 grams of saturated fatty acids per day, which is equal to about three tablespoons of butter.
Unsaturated fats are a type of fats that have one or more double bonds between the carbons in the chain. Thus not all of the carbons have hydrogens stuck to them. Unsaturated fats can be monounsaturated (with one double bond) or polyunsaturated (with multiple double bonds).
- Have one or more double bonds in their chemical structure
- Are chemically unstable and can break down in the body to produce excess levels of free radicals. (factors in heart disease and cancer)
- Are more fluid, less sticky.
- Are liquid at room temperature
- Are critical in the body because they provide flexibility to cell membranes and allow the cells to stay in dynamic communication with their surroundings
Note: These fats are very unstable and highly reactive to light, heat, and oxygen. They should not be used for cooking and always stored away from heat and light to help prevent oxidation (damage). We can refrigerate them, store them in airtight green or brown glass containers, open them minimally, or even add antioxidants like vitamin E.
There are two types of unsaturated fats depending on the degree of their unsaturation:
- Monounsaturated (they have one double bond)
- Polyunsaturated (they have more than one double bonds)
Monounsaturated Fats (MUFAs)
This type of fats has been linked to:
- Improved levels of blood cholesterol (i.e., raising good HDL cholesterol while lowering bad HDL cholesterol)
- Insulin and blood sugar control
- Lowering inflammation
- Lowering breast cancer risk (potentially)
- Increasing feelings of fullness thus leading to reduced calorie intake and weight loss
- A reduced risk of heart disease and diabetes.
- Potentially reducing inflammation and enhance insulin sensitivity
- Having positive effect on brain function and health
Where to find them:
- Olives and olive oil
- Nuts (almonds, primarily, followed by cashews, pecans, pistachios, and macadamias)
- Peanut butter
Polyunsaturated Fats (PUFAs)
Polyunsaturated fats tend to remain liquid, even when refrigerated. Polyunsaturated fats tend to oxidize easily and should not be used for cooking at high temperatures. These are best kept in dark bottles or other dark packaging in cool, dark places.
These types of fats are considered as essential fats. This means that although they are very important for many bodily processes, we cannot produce them on our own, therefore it is essential that we obtain them through our diet. Polyunsaturated fats are needed and beneficial for a number of things, such as:
- Building cell membranes and covering up our nerves. They help maintain the fluidity of the membranes, and are involved in the movement of substances in and out of our cells.
- Lowering blood pressure, arrhythmia (irregular heartbeat), stroke, inflammation, diabetes, and heart disease risk
- Improving blood cholesterol
- Muscle movement
- Blood clotting
- They govern growth, vitality, and mental state. They are involved in energy production mechanisms in our body.
- Brain health and development
- They are thought to be involved with the transfer of air in our lungs, through the thin lung tissue, through the capillary walls that carry blood, and across the membranes of our red blood cells.
- Slowing the build-up of plaque in arteries
- They are precursors of prostaglandins, some of which lower blood pressure, relax coronary arteries, and inhibit platelet stickiness.
There are a few polyunsaturated fat types: omega-3 fatty acids, omega-6 fatty acids, and omega-9 fatty acids, all essential, but some of these are needed in much different amounts. Most of the PUFAs in our cell membranes are either omega-6s or omega-3s.
Sources of Omega-3s:
- Fatty fish (salmon, mackerel, anchovies, herring, sardines)
- Cod liver oil
- Raw dairy
- Grass-fed beef
- Pasture-raised or omega-3-enriched eggs
- Chia, flax, sacha inchi, and hemp seeds
Sources of Omega-6s:
- Sunflower oil
- Poppyseed oil
- Corn oil
- Walnut oil
- Cottonseed oil
- Soybean oil
- Sesame oil
There are two Essentially Fatty Acids (EFAs) that we must consume in food: linoleic acid (LA), an omega-6 fatty acid, found mainly in vegetable oils, and alpha-linolenic (ALA or NLA), an omega-3, found in chia seeds, flaxseeds, perilla seeds, hemp seeds, walnuts etc.
Omega-6 to omega-3 ratio:
When it comes to the right amount of omega-6s and omega-3s, the majority of studies support a ratio somewhere between 2:1 and 4:1, or at least twice the amount of omega-6s as omega-3s, but no more than 4 times as much.
For the first 2,5 million years of the human genus, Homo, and the first 500,000 years of our species, Homo sapiens, humans ate these omega-6 and omega-3 fatty acids at roughly 1:1 ratio. We consumed things like plants and seeds that had omega-6, but we also consumed a lot of wild animals that foraged for grasses, other greens, and wild fish, all of which contain omega-3 fatty acids. This provided us with that 1:1 balance associated with lower risk of both neurological and cardiovascular diseases.
Today our lifestyle and diet are much different. That ratio has been dramatically skewed in favour of omega-6 fatty acids, and the amount of omega-3 fatty acids has seriously declined. The introduction to the human diet of seed oils such as corn oil, soybean oil, and canola oil – which were originally considered waste products – as well as an increase in feeding animals grain rather than grass (reducing the omega-3 fatty acid content in their meat) led to the high increase in omega-6 consumption.
When the ratio shifts too far toward omega-6 fatty acids, many of our chemical pathways tilt toward inflammation and the development of chronic disease. As a result, we are much more likely to develop excessive inflammation in our blood vessels, leading to higher rates of autoimmune problems, atherosclerosis, heard disease, and mental health problems. This can easily be reversed, however, by ramping up the amount of grass-fed meat and wild-caught fish in our diet (while simultaneously eliminating or minimizing the consumption of vegetable oil).
Trans fats are created in an industrial process that adds hydrogen to liquid vegetable oils to make them more solid. These kinds of fats could be harmful for our health. You should avoid products that have “hydrogenated” or “partially hydrogenated oil” on a label. Common foods that might contain these bad fats include margarine, most processed junk food, packaged cookies, frozen desserts, and pizzas.
Studies have found that consuming trans fats can increase the “bad” LDL cholesterol and lower the “good” HDL cholesterol, which puts people more at risk for heart disease. Trans fats may increase the risk of developing type 2 diabetes due to their contribution to insulin resistance. Trans fats have also been linked to increased inflammation and damage to blood vessels.