Over the past several decades, much focus has been paid to both dietary and blood levels of cholesterol. However, despite countless studies conducted on the subject, misinformation is rampant and most would likely admit they are still hesitant to ditch their “low-fat” mindset. Healthy Living How To friend Katelyn Madsen joins us today for a guest post tackling the topic of cholesterol and diet.
Won't eating fat clog my arteries, raise my cholesterol and give me heart disease? As a Registered Dietitian and weight loss coach, this is one of the most common questions I receive from clients and people in general, when I suggest ditching their low-fat diet in favor of a diet rich in vegetables, protein and healthy fats like butter, coconut oil, avocado and full-fat dairy. As a whole, when it comes to fat and cholesterol, we are more confused than ever. In today's article, I will clarify the following:
- What is cholesterol?
- What functions does it have in the body?
- How are cholesterol levels affected by diet?
Cholesterol is a waxy, fat-like substance that’s found in all cells of the body. Your body needs cholesterol to make hormones, vitamin D and bile acids; substances that help you digest foods. Cholesterol travels through your bloodstream in small packages called lipoproteins. These packages are made of fat, a.k.a., lipids on the inside and proteins on the outside.
- Lipids are a major form of stored nutrients, primarily in the form of triglycerides
- They serve as precursors for adrenal and sex hormones, as well as vitamin D and bile acids
- Lastly, lipids play a role as cell messengers
Lipoproteins are vehicles which transport lipids in the blood. Lipids are fat-soluble particles, which are insoluble in blood, therefore, they must be combined with proteins to form lipoproteins. Lipoproteins are classified by their density and major lipid component. Those whose main components are lipids are less dense; while those composed of proteins have greater densities. There are several forms and subclasses of lipoproteins, but to avoid confusion, this article will focus on the main forms you are most likely familiar with:
Very Low Density Lipoproteins (VLDL)
- Major lipid component is triglycerides
- Synthesized by the liver
- Transport triglycerides to peripheral tissues
Low Density Lipoprotein (LDL)
- Major lipid component is cholesterol
- Derived from VLDL and IDL by lipase hydrolysis of triglyceride
- Major carrier of cholesterol, which is used by peripheral tissue
High Density Lipoprotein (HDL)
- Major lipid components are phospholipids and cholesterol
- Synthesized by the liver and intestine
- Also derived from the surface of chylomicrons and VLDL during lipolysis
- Facilitate removal of cholesterol from peripheral tissues
- Redistribute cholesterol to other tissues and to the liver
Now that we have defined what cholesterol is, have a better understanding of its many forms and what they are composed of, I’d like to turn our focus to diet and its relation to our cholesterol levels.
Diet & Cholesterol Levels
It has literally been engrained in our heads that fat, specifically of the saturated form, clogs arteries and raises cholesterol and higher cholesterol leads to an increased risk of cardiovascular disease. Therefore, one would assume the removal of dietary fats and cholesterol would result in lowering one’s risk for developing chronic diseases. Makes sense right? Wrong.
How is it then that some people who eat diets containing high levels of saturated fat and cholesterol through blood work prove to have normal cholesterol levels, while others have high? And those on the other end of the spectrum, who follow what they believe to be a “heart healthy”’ diet, low in dietary fats and cholesterol, also show a mix in cholesterol levels?
More in-depth reviews of research conducted over the past several decades are starting to disprove these commonly held myths we’ve all been taught to believe are fact. It is critical when analyzing any study conducted to consider the type of study. After more thorough review, it has become clear that such claims have been based off association studies. Association studies study the occurrence together in a population of two or more traits. They may show, for instance, that increased dietary fat and cholesterol consumption is associated with elevated cholesterol and heart disease; but, they fail to prove the cause and effect relationship between two factors. Unfortunately, this conclusion is what has been drawn from such studies for years.
Trans Fats, Cholesterol & Inflammation
Recent research is showing trans fats and the inflammation it promotes in our bodies is what is most threatening to our overall health and well-being. Trans fats, commonly found in heavily processed foods, lower HDL and raise LDL levels. However, what is even more concerning is the fact trans fats have been shown to increase the development of visceral fat, commonly called “belly fat”. This fat, stored in our mid section, promotes inflammation through its release of inflammatory cytokines. Inflammation paired with oxidation, essentially the “rusting of our cells”’, is what deserves more of our attention.
What can we do to reduce this inflammation? There are several things, but of them, the two most important would be:
- Weight loss through a diet rich in non-starchy vegetables, naturally derived fat sources, and proteins paired with regular activity
- Supplementation of the diet with omega 3 fatty acids through fish oils, shown to lower inflammation and reduce triglyceride levels in the blood
Something worth encouraging is the avoidance of commonly used vegetable oils, which are laden with omega 6 fatty acids, found to be pro-inflammatory and encourage oxidation. These oils, such as soybean, canola, and corn oil, are commonly found in refined and processed foods like cookies, crackers, snack mixes, etc.
Carbohydrates & Cholesterol
Focusing specifically on carbohydrate intake, studies are showing excessive carbohydrate consumption to negatively impact cholesterol levels. I want to make clear the form of carbohydrates I am referring to. Carbohydrates are a necessary part of most individuals’ diets. However, all carbohydrates, just like all fats, are not created equal. Carbohydrate consumption should be based off one’s activity level and derived mainly from vegetables, some fruit, and if tolerable, dairy. Beans, lentils, and legumes are also decent options due to the fiber and protein they contain. However, most individuals’ activity levels on a daily basis do not justify a regular need for these carbohydrate rich foods. The forms of carbohydrates we most want to avoid are processed grain products and those with added sugars. Regular consumption of these products increase blood sugar, which has clearly been linked to elevated triglycerides. Compounding the effect, the gluten found in some grains, such as wheat, barley, and rye, is proving to be a pro-inflammatory molecule.
Protein & Cholesterol
Regarding protein, aside from the fact that ample protein in one’s diet leads to increased satiety and therefore, encourages decreased cravings for excessive carbohydrate consumption, it also provides some added benefits such as:
- Assisting the body in repairing tissues and recovering from stressors, which result in oxidation and increased inflammation
- Managing blood sugar, resulting in lower triglyceride levels
Optimal Health & Well Being
It is continuously becoming clear how a diet full of natural foods with little to no adulteration lays the foundation for optimal health and well-being. This paired with daily activity, adequate sleep, and hydration optimizes our health and metabolism. Additionally, supplementation through a high quality multivitamin and fish oils provides nutrients where our food supply today lacks. By making these basic principles habit and regular comprehensive blood testing a priority, you will be protecting yourself from a multitude of ill-health consequences down the road.
Katelyn Madsen is a Registered Dietitian, weight loss coach, lab testing lead and metabolic tech for Life Time Fitness. She received her Bachelors in dietetics from Iowa State University in Ames, Iowa, and then went on to complete her accredited dietetic internship through the University of Michigan Health System in Ann Arbor, Michigan.
Katelyn fully supports a comprehensive approach to weight management and overall health, focusing first on establishing an efficient metabolism through healthy dietary and lifestyle habits.