Chances are, when you hear the word cholesterol, you think about eggs and your doctor telling you that you need to lower your cholesterol levels, but do these go hand in hand?


The short answer: kind of. To understand how dietary cholesterol and cholesterol in your blood relate, let’s first go over what constitutes cholesterol. Dietary cholesterol is a fat-like, clear liquid found in all animal cell membranes, and thus only animal products. Cholesterol is important because it is a precursor for testosterone, estrogen, and vitamin D; all of which are extremely important for your body to function properly.

Now you may be wondering about diets low in – or even excluding – animal products and how the body is able to still produce these hormones (yes, vitamin D is considered a hormone because it can be synthesized by the body in one place and regulates activities in another).

The liver is key when it comes to cholesterol, both in regulation and production. That’s right, your liver on average produces around 75 percent of the total cholesterol in your system. When you intake higher levels of cholesterol, your liver begins to produce less due to negative-feedback mechanisms.

This means that when you eat more cholesterol, the body produces less in order to try to maintain homeostasis. Some adjust more efficiently than others, but that depends on genetics.

Don’t misunderstand, your blood levels of cholesterol will rise after you eat a meal high in cholesterol, but that does not mean that you have dyslipidemia (chronic abnormal cholesterol/triglyceride levels). Just like if you were to eat a meal rich in simple carbohydrates, your blood glucose levels will rise immediately afterwards, but this certainly does not mean that you have diabetes.

In addition to not producing as much cholesterol, the liver can also eliminate excess from the body by converting it into bile acids, which are then bound together and excreted naturally. The liver is able to do this with the help of HDLs (high-density lipoproteins) and a process known as reverse cholesterol transport. This is why HDL is known as the “good cholesterol.” You should strive to have levels above 60 mg/dL as these levels actually counts as a negative health-risk for coronary artery disease. When you get your cholesterol levels checked at the doctor, HDLs are only one part of the puzzle, with LDLs (low-density lipoproteins) and triglycerides being the other two.

LDL has an important role in the body, too. It is responsible for delivering cholesterol to cells where it can then be used for cell membranes or the production of hormones. LDL is the molecule resulting after VLDLs (very-low-density lipoproteins) release their triglycerides to various cells in the body. Higher levels of triglycerides means higher levels of VLDLs, and therefore higher levels of LDLs. Problems start to arise when your body cannot remove triglycerides and LDLs from the blood at an adequate rate, which can lead to plaque buildup on your artery walls known as atherosclerosis. When these plaques rupture, a blood clot can form causing a heart attack.

Now onto why you’re reading this; what causes high levels of LDLs and triglycerides? We know for a fact that trans fat will raise these. Trans fats are found in vegetable oils that have been converted to solids (e.g. margarine and many peanut butters). The tricky thing is that if there is less than 0.5g of trans fat per serving, then the label is allowed to state 0g trans fat. To remedy this problem, nutritionists suggest looking at the ingredients to check for hydrogenated oils.

On the other hand, unsaturated fats can actually lower these levels and are found in fish and many plants (e.g. avocados, seeds, and nuts). Where things start to get tricky is saturated fat. For years, it has received a bad rap as a major cause of heart disease (largely due to the sugar industry influencing scientists in the 1960’s to point fingers elsewhere). In fact, recent research is starting to question the extent of health risks associated with saturated fats. The bottom line is, for now, you should still limit saturated fats to 10 percent of your daily caloric intake, exclude trans fats, and aim for up to 10-20 percent of your daily calories coming from mono- and polyunsaturated fats. Lower fat intake generally means lower cholesterol intake, so you don’t really need to worry about tracking how much cholesterol you are eating, unless instructed by a healthcare professional. So yes, you can have your eggs and eat them, too.

Of course a lot of this has been simplified, and has not taken into account numerous factors like the role of medications, exercise, metabolic diseases, sugar, etc., so take this all with a grain of salt… provided you don’t have hypertension.


Ben Stokes has a bachelors degree in kinesiology and is a certified exercise physiologist from the American College of Sports Medicine.