Fats are essential to human health at every level beginning at a cellular base; however, decades of misinformation regarding the healthfulness of fat has meant that many people actively avoid nourishing, fat-rich foods. Low-fat diets are still popular today with many people who are striving to eat healthily or manage their weight. Fat is perhaps one of the most unfortunate homonyms, because body fat (adipose tissue) compared with the nutrient are very different things. As a result of this syntax, the fear of dietary fat has become deeply entrenched. However, if we look at the science we discover that fat is actually incredibly nourishing and a nutrient that humans have always eaten in support of good metabolic health. This article first looks at why humans need fat at a cellular level and then moves onto examine the issues associated with consumption of poor quality fats.
Our cells are made from cholesterol and fatty acids
At the cellular level fats, also referred to as lipids, are essential for the very structure of our cells. The plasma membrane is a cell’s flexible outer surface that separates the contents of the cell from the external environment in the body and is made from certain lipids and proteins. The lipid bilayer is the foundation structure of the plasma membrane and is made of phospholipids, cholesterol and glycolipids. Phospholipids are arranged tails-to-tails in a double row to form the membrane that surrounds each of our cells. Within the plasma membrane cholesterol molecules help the cell maintain its shape and structure – without this cholesterol the membrane fluid would not remain smooth and consistent. Cholesterol is a type of steroid, which is special type of lipid made of four rings of carbon. Without these important fatty structures our cells would lack the capacity to absorb and produce certain important compounds such as DNA. Our bodies have the capacity to produce some cholesterol (via the liver) and some fatty acids; however, to support healthy cell structure and metabolism it is important we consume plenty of fat from healthy dietary sources.
The “Cellular downward spiral” illustrates that cells that lack certain components or nutrition have a knock on effect to every other system in our bodies. Cellular inefficiency means organ inefficiency, which impairs detoxification with a knock on effect to our body’s ability rebuild and repair. This can eventually lead to disease. Lipids can be catabolised to produce energy for our cells in the form of adenosine triphosphate (ATP), because the glycerol molecule attached to triglycerides can enter the cell respiration chain. This illustrates that although a balance of macronutrients is ideal, the human body can in fact survive without carbohydrate. It cannot however, survive without some fat and protein. If our cells become adept at performing the fat- glucose- ATP conversion then we have successfully shifted from being primarily “sugar-burners” to improving our function as “fat-burners,” with positive impacts for metabolic health.
Every cell in the human body requires fat for structural integrity and healthy function.
Fat is used to form hormones
In addition to fat being essential for cellular structure and health, certain fatty acids and structures play other critical roles in the body. For example cholesterol is the precursor to many types of steroid hormones including oestrogen and testosterone, which are obviously critical to reproductive function. Fat also helps to regulate blood sugar and appetite as it has a satiating effect and can dull insulin responses to certain foods.
There are four vitamins that require fat to be properly absorbed. Vitamin A, D, E and K are the “fat-soluble” vitamins, meaning they require fat to be properly broken down and assimilated by the body. Vitamin D deficiencies are increasingly common in developed countries with implications for bone and mental health in particular. It is important that Vitamin D – in food or supplement form – is accompanied by healthy fat to enable absorption.
The problem with the wrong fats
Misleading studies and powerful food manufactures have combined to convince many of us that saturated fat is evil and to be avoided. However, saturated fat is the most stable of all three fats due to the absence of double bonds. Polyunsaturated fats contain many double bonds and are therefore unstable and prone to causing oxidative damage due to the release of free radicals in our bodies. These oils are particularly problematic when heated because this makes them even more unstable. Unfortunately these oils are more commonly used in commercial kitchens because they are cheaper and more convenient. Many people also choose to cook with these fats because they have been convinced that they are a healthier choice that will actively lower cholesterol and prevent heart disease. We should be choosing saturated fats for cooking as they are the most stable and also taste delicious!
Also detrimental to human health are hydrogenated fats. Hydrogenated fats, also known as trans-fats, were developed in response to demand for an unsaturated fat that would remain solid at room temperature. Hydrogenated fats are produced with a nickel catalyst. The cis-formation of naturally occurring fatty acids is restructured to form a trans-formation, which means a hydrogen atom is moved to the other side of the fatty acid to allow it to pack together and be solid at room temperature. This is how non-animal, solid fat products such as margarine are produced. When we consume fats with the trans-formation our cells cannot tell the difference and they are actively incorporated into our cells just like other fatty acids. This wreaks havoc with our cell metabolism, because trans-fats prevent our cells from performing certain critical functions that can only occur when electrons are in very specific arrangements. Sally Fallon outlines these effects ranging from cancer to immune dysfunction, birth defects and mental health issues. Hydrogenated fats should be actively avoided for cellular health. Read my review of her excellent book in this article.
This article has covered the importance of healthy, nourishing fats at a cellular level. The impacts of a low-fat diet can have serious health repercussions and the body will need support to recover. For more information please get in touch with me via the contact section of the blog.