What cholesterol is, what it does, its importance for health, and common misconceptions: ten questions and answers.
1. What is cholesterol?
It is a molecule of the lipid class (For detailed information about lipid types, see Lipids; Classification, Fatty Acids, Fats and Oils). It is not found in plant foods, it can only be found in animal foods in varying amounts. In addition, the human body produces between 1 and 4 grams of cholesterol per day.
2. Is cholesterol a completely harmful compound for the body?
No. On the contrary, cholesterol has very important functions in the body.
It is involved in the digestion of fats. Therefore, if there is not enough cholesterol in the body, there may be problems in the digestion of fats.
Another important function of cholesterol is its role in the structure of nerve tissue.
So much so that 17% of the dry matter weight of the brain is cholesterol. Cholesterol is an indispensable building material for nervous system tissues. However, they also participate in the structure of the cell wall in other tissues.
Cholesterol is also the precursor to vitamin D produced in the body.
3. What is the negative effect on health?
The melting point of cholesterol is 159oC. There are constantly 10-12 grams in the blood and this is normal. If the amount of cholesterol in the blood is constantly high; it accumulates in the vessel walls over time and can cause occlusion of the vessels. However, it should be known that cholesterol is not the only substance responsible for deposits in blood vessels.
This effect is not an instantaneous problem, individuals with high cholesterol levels over a long period are at risk in this regard.
What causes heart attack?
While routine blood flow continues in the arteries, over decades, some deposits can accumulate in some arteries and form a plaque structure, like garbage and silt accumulated on one side of a river. These deposits, called plaques, form inside the arteries and are mainly composed of cholesterol, inflammatory immune cells, calcium, and many other components . Over the years, the amount of this deposit increases over the years, and, as can be expected, the patency of the arteries decreases, and blood flow becomes difficult.
Plaques formed on the arteries that feed the heart (coronary) cause the heart muscle to have difficulty receiving enough blood. This problem manifests itself with an intermittent and severe pain called angina pectoris. Angina pectoris can be considered a precursor and sign of a much more serious problem, namely a heart attack.
You can compare this situation in the arteries to the flow in a stream. Over time, deposits form, and the flow becomes difficult. One day, the water pressure breaks up the deposit and tries to ease the flow. This is also what happens in the arteries. Over the years, the plaque gradually grows, the pressure of the flow increases in the narrowed vessel opening, and one day, the blood disperses that plaque; in other words, the plaque breaks.
The real story of a heart attack begins after this. Just as when a cut or injury occurs anywhere in our body, the blood in that area immediately clots and prevents blood flow and, therefore, blood loss; when a plaque breaks, the body’s injury controllers think that the plaque is a part of the body and immediately clot the blood in the part of the plaque that is broken. The clotting that occurs in the vessel brings the blood flow to a complete halt. While the body thinks that an injured area is closed, the blood flow that is forced into the vessel actually almost comes to a standstill, and as a result, a heart attack occurs.
The real problem in a heart attack is not the plaque breaking but the blood immediately entering the clotting process in the part of the broken plaque. For this reason, blood thinners (preventing clot formation) such as aspirin are prescribed to individuals at risk of heart attack.
*I am grateful to Dr. Siddhartha Mukherjee for “The Song of the Cell”
4. What does the level of cholesterol in the blood depend on?
•Genetic predisposition,
• Excess weight and obesity,
•Nutrition habits,
• Stress.
Genetic inheritance from the family can cause high cholesterol levels in the blood of the individual. To control this situation, it is extremely important to seek the opinion of a doctor and to comply with the doctor’s instructions in this context. However, controlling other factors can help balance blood cholesterol levels.
5. What about nutrition and cholesterol?
It is recommended that dietary intake should be a maximum of 300 mg per day. As mentioned before, no plant foods contain cholesterol, only animal foods. Only 50-60% of cholesterol taken with food can be absorbed by the body.
6. Should we be afraid of animal foods?
Individuals who are healthy and do not have risk factors should not be afraid. Of course, this does not mean that healthy people can overeat foods high in cholesterol. Eating enough and in moderation is essential.
Individuals with one or more of the risk factors and individuals with high cholesterol levels in the blood should be careful against foods with high cholesterol.
However, every person should have their blood cholesterol level measured regularly once or twice a year. In particular, individuals with a history of cardiovascular disease in their family and close relatives should pay attention to this situation.
7. Which foods contain high amounts of cholesterol?
Foods at risk for cholesterol are the brain, liver and eggs.
• 2 thousand 195 mg per 100 grams of the brain,
• Liver 309 mg per 100 grams,
• 1 egg contains approximately 200 mg.
However, it should be kept in mind that caviar, lobster and crab also contain high amounts of cholesterol, although they are not consumed frequently.
8. What about meat, milk, cheese and butter?
• 100 ml of whole milk 13 mg,
• 100 g veal 83 mg,
• 100 g butter 237 mg,
• 100 gr cheese 100-200 mg,
• 100 g of yogurt contains 13 mg of cholesterol.
Healthy individuals should not be afraid if they consume these foods in moderation. It should be noted that the recommended daily intake of cholesterol is at most 300 mg.
9. What can be advised for these foods?
Considering a daily butter intake of 10–20 g, the amount of cholesterol obtained from butter is approximately 25–50 mg.
A daily portion of 10–50 g of cheese is also appropriate.
One of the biggest mistakes individuals make to gain weight and develop their bodies is to consume a high number of eggs. Consuming 5 eggs a day means taking approximately 1000 mg of cholesterol into the body. This bad diet will invite serious cardiovascular diseases in the future. 1 egg a day is ideal in terms of cholesterol intake.
10. What should be the level of cholesterol in the blood?
For a healthy adult individual, the total cholesterol level in the blood is expected to be 200 mg/dl and below.
A total cholesterol level of 200-239 mg/dl is accepted as the limit value. 240 mg/dl and above are considered high values.
LDL* level in the blood should be below 100 mg/dl. LDL is popularly known as “bad cholesterol.” LDL value in the range of 100-129 mg/dl is acceptable for individuals without health problems; however, this value range is a situation that should be considered especially in individuals with cardiovascular disease and individuals at risk of cardiovascular disease (excessive weight, stress, routine diet with high cholesterol content and genetic predisposition). The range of 130-159 mg/dl for LDL is borderline high; 160-190 mg/dl is high; Values of 190 mg/dl and above are considered very high.
HDL** level should be kept high. HDL is popularly known as “good cholesterol.” HDL values lower than 40 mg/dl are considered an important risk factor for heart disease. Values between 41-59 mg/dl for HDL are considered borderline low. The HDL level should be 60 mg/dl and above.
*LDL; Low-Density Lipoprotein. Lipoprotein is used because cholesterol is bound to proteins in the blood. **HDL; High-Density Lipoprotein.
Note: This article is intended solely for general informational purposes. It does not constitute medical advice or personalized nutritional guidance. Nutritional needs may vary from person to person. Always consult a healthcare professional or a registered dietitian before making any dietary changes.
References
Raymond, J. L., & Morrow, K. (2023). Krause ve Mahan Besin ve Beslenme Bakım Süreci (16. baskı; G. Akbulut, Çev. Ed.). Nobel Tıp Kitabevleri.
Aksoy, M. (Ed.). (2022). Beslenme Biyokimyası (7. baskı). Ankara Nobel Tıp Kitabevleri.
Saldamlı, İ. (Ed.). (2021). Gıda Kimyası. Hacettepe Üniversitesi Yayınları.
Mukherjee, S. (2022). The Song of the Cell: An Exploration of Medicine and the New Human. Scribner.
National Heart, Lung, and Blood Institute. (2024). Blood Cholesterol: What Is Blood Cholesterol?.
National Heart, Lung, and Blood Institute. (2024). Blood Cholesterol: Diagnosis.
National Heart, Lung, and Blood Institute. (2024). Atherosclerosis: What Is Atherosclerosis?.
World Health Organization. (2023). Saturated fatty acid and trans-fatty acid intake for adults and children: WHO guideline.
Here’s an article that might interest you; Fats and Oils; Functions in the Body, Nutritional Importance and Daily Needs
Halil İbrahim Akgül
Halil Ibrahim Akgul, Ph.D., is an Assistant Professor of Food Engineering at Bayburt University, where he works in the Division of Food Sciences within the Faculty of Engineering. He received his B.Sc. in Food Engineering from Akdeniz University in 2010, followed by an M.Sc. and a Ph.D. in Food Engineering from Atatürk University in 2015 and 2020, respectively. His formally recognised academic fields are Food Sciences and Engineering, Food Technologies, Dairy and Dairy Products Technology, and Food Microbiology.
Dr. Akgul has more than fifteen years of professional, research, and academic experience in food science. Between 2011 and 2013, he worked as the food engineer responsible for operations at the Pilot Dairy and Bread Factory of Atatürk University’s Directorate of Agricultural Enterprises. This industrial experience, combined with his subsequent academic research, gave him extensive practical and scientific knowledge of milk processing, dairy production, food quality, hygiene, and product development.
His research is primarily focused on milk and dairy products, dairy microbiology, starter cultures, lactic acid bacteria, exopolysaccharides, butter technology, and the physicochemical, microbiological, sensory, and nutritional properties of foods. His studies have examined the quality and fatty-acid composition of traditional butter, aroma formation in butter produced with different starter cultures, raw-milk quality, the characterisation and antioxidant activity of bacterial exopolysaccharides, traditional dairy products such as çökelek and karın kaymağı, colostrum powder, and the use of fruit-derived ingredients in ice cream production.
His academic record includes peer-reviewed research articles published in national and international journals, including Mljekarstvo, Acta Scientiarum Technology, the Journal of Food Safety and Food Quality, the International Journal of Food Engineering, the Atatürk University Journal of Agricultural Faculty, and ATA Food Journal. Four of the research articles currently listed in his university profile were published in SCI-Expanded-indexed journals. He has also contributed to twelve national and international conference papers and presentations covering dairy products, food microbiology, butter quality, fatty-acid composition, starter cultures, exopolysaccharide-producing bacteria, colostrum, traditional foods, and functional ice-cream formulations.
Dr. Akgul has participated as a researcher or adviser in eleven completed scientific and applied research projects. These projects have addressed the modernisation of pilot dairy-processing facilities; the production and quality characteristics of colostrum powder; the physicochemical and microbiological quality of butter and raw milk; the identification of exopolysaccharide-producing lactic acid bacteria; the development and production optimisation of starter cultures for mould-ripened cheese; the standardisation of traditional dairy products; and the use of sloe berry and persimmon fibre in ice-cream production.
His teaching experience spans undergraduate, associate-degree, and graduate education. The courses he has taught include Food Chemistry, Analytical Chemistry, General Chemistry, Organic Chemistry, Fermented Dairy Products Technology, Butter Production and Processing Technology, Healthy Living and Nutrition, Organic Agriculture and Food, Popular Science, Digital Literacy, and Information Technologies. Through these courses, he combines fundamental food chemistry and engineering principles with dairy technology, nutrition, scientific literacy, and the practical communication of scientific knowledge.
He is the founder and Editor-in-Chief of Gıda ve Sağlık, a multilingual digital publication devoted to food, nutrition, health, food chemistry, food microbiology, and culinary science. Through this platform, he draws upon his academic background, teaching experience, research activity, and practical knowledge of food production to present scientifically grounded information in a detailed and accessible form for an international readership.