Which type of fat contributes to high cholesterol?

October 28, 2025 •

4 min read

According to the American Heart Association, decades of scientific evidence prove that saturated and trans fats can raise your “bad” LDL cholesterol and put you at higher risk for heart disease. Understanding which type of fat contributes to high cholesterol is key to making heart-healthy dietary choices. While fat is a necessary nutrient, not all types are created equal regarding their impact on your blood lipids.

Quick Summary

This article explores how saturated and trans fats directly influence blood cholesterol levels, detailing their sources and explaining the difference between LDL and HDL cholesterol.

Key Points

Saturated Fat: Eating too much saturated fat, found in red meat and full-fat dairy, is a primary cause of high LDL ('bad') cholesterol.
Trans Fat: Artificial trans fats, historically in processed foods, both raise 'bad' LDL and lower 'good' HDL cholesterol.
Unsaturated Fats: Healthy unsaturated fats, like monounsaturated and polyunsaturated types, can help lower cholesterol when replacing unhealthy fats.
Label Reading: Checking food labels for saturated and trans fat content is a practical way to manage your intake.
Heart-Healthy Replacements: Swap saturated fats found in butter and fatty meats with unsaturated fats from sources like olive oil, fish, and nuts.
Cooking Methods: Choose baking, steaming, or grilling over frying to reduce your intake of unhealthy fats.

Understanding the Link Between Fat and Cholesterol

Cholesterol is a waxy, fat-like substance that is essential for building healthy cells. The liver produces all the cholesterol the body needs, but it's also obtained from animal-based foods in our diet. While cholesterol is vital, high levels of certain types can increase the risk of heart disease. The crucial distinction lies in the lipoproteins that transport cholesterol through the blood.

Low-density lipoprotein (LDL), often called “bad” cholesterol, transports cholesterol to the body's cells. High levels can lead to the buildup of plaque in the arteries, a condition called atherosclerosis, which narrows or blocks blood flow.

High-density lipoprotein (HDL), known as “good” cholesterol, carries cholesterol from the arteries back to the liver, which then disposes of it.

The Negative Impact of Saturated Fat

Saturated fats are the primary dietary culprits for raising high cholesterol levels. These fats are typically solid at room temperature and are found in many animal products. When you consume too much saturated fat, it changes how the liver processes cholesterol, causing LDL cholesterol to accumulate in the bloodstream.

Foods commonly high in saturated fat include:

Fatty meat: Beef, lamb, pork, and processed meats like sausage and bacon.
Full-fat dairy: Butter, cheese, whole milk, cream, and ice cream.
Tropical oils: Coconut oil, palm oil, and palm kernel oil.
Baked goods: Commercial cakes, cookies, and pastries made with butter or shortening.

The Double-Trouble of Trans Fat

Trans fat is arguably the worst type of fat for your cholesterol levels. It not only raises your “bad” LDL cholesterol but also lowers your “good” HDL cholesterol. Most trans fat is artificially created during a process called hydrogenation, where liquid vegetable oils are turned into solid fats. The U.S. Food and Drug Administration has banned the use of partially hydrogenated oils in processed foods, but trace amounts may still exist, and they are used in other countries. Naturally occurring trans fats in animal products are less of a concern.

Artificial trans fats are often found in:

Fried foods: Especially fast-food fries, fried chicken, and battered seafood.
Baked goods: Some pre-made cakes, pies, and cookies.
Margarine: Some stick margarines and vegetable shortenings.

The Healthier Alternatives: Unsaturated Fats

Not all fats are harmful. Unsaturated fats, found primarily in plant and fish sources, are heart-healthy and can help improve cholesterol levels when they replace saturated and trans fats in the diet. They are typically liquid at room temperature.

Monounsaturated Fats

These fats can help reduce LDL cholesterol levels while maintaining healthy HDL levels. Foods rich in monounsaturated fats include:

Olive oil and canola oil.
Avocados.
Nuts like almonds, peanuts, and cashews.

Polyunsaturated Fats

Polyunsaturated fats, which include essential omega-3 and omega-6 fatty acids, also help lower LDL cholesterol. The body cannot make these fats, so they must be obtained from the diet. Foods rich in polyunsaturated fats include:

Oily fish, such as salmon, mackerel, and herring.
Sunflower, corn, and soybean oils.
Seeds and nuts.

A Comparison of Dietary Fats and Cholesterol Impact


Fat Type	Common Sources	Effect on LDL ("Bad") Cholesterol	Effect on HDL ("Good") Cholesterol	Temperature	Key Recommendation
Saturated	Red meat, butter, palm oil	Increases significantly	Increases slightly	Solid	Limit intake
Trans	Fried foods, packaged baked goods	Increases significantly	Decreases	Solid	Avoid entirely
Monounsaturated	Olive oil, avocados, nuts	Decreases	Maintains or increases	Liquid	Prefer over saturated fats
Polyunsaturated	Oily fish, sunflower oil, seeds	Decreases	Decreases	Liquid	Prefer over saturated fats

Simple Steps for a Healthier Diet

Making conscious food choices can significantly improve your cholesterol levels. It is recommended to limit saturated fat intake to less than 6% of your total daily calories and completely avoid artificial trans fats. Replacing unhealthy fats with healthy unsaturated fats is a key strategy for maintaining heart health. Reading food labels to check fat content, including the percentage of saturated fat, is a practical habit. Choosing to bake, steam, or grill food instead of frying it can also make a major difference. Focusing on whole foods such as fruits, vegetables, whole grains, nuts, seeds, and lean proteins helps reduce the overall intake of unhealthy fats. For more detailed dietary guidance, consider consulting an organization like the American Heart Association to learn more about eating smart for your heart health.

Conclusion

In summary, the fats that contribute most significantly to high cholesterol are saturated fats and, even more harmfully, artificial trans fats. Saturated fat raises LDL cholesterol, while trans fat performs a harmful double-action of increasing LDL and decreasing beneficial HDL. Shifting dietary patterns away from these unhealthy fats and toward healthier, unsaturated alternatives like monounsaturated and polyunsaturated fats is crucial for lowering cholesterol and reducing the risk of heart disease. Making informed food choices and reading nutrition labels are effective steps toward a heart-healthy diet.

Frequently Asked Questions

LDL (low-density lipoprotein) is considered "bad" cholesterol because it transports cholesterol to the arteries, where it can build up as plaque. HDL (high-density lipoprotein) is "good" cholesterol because it carries excess cholesterol from the arteries back to the liver for removal.

For most healthy people, the cholesterol in eggs has a smaller effect on blood cholesterol levels compared to saturated and trans fats. It's more important to limit saturated fat intake.

Despite their reputation, tropical oils like coconut and palm oil are high in saturated fat and can contribute to high cholesterol. They should be used sparingly.

The American Heart Association recommends aiming for a dietary pattern that achieves less than 6% of total calories from saturated fat. For a 2,000-calorie diet, this is about 13 grams or less per day.

Artificially produced trans fats are found in some commercially baked goods, fried foods, and certain margarines. Checking labels for "partially hydrogenated oils" is the best way to identify them.

Cheese is often high in saturated fat. While some studies suggest calcium in cheese might mitigate its effect, it's still best to consume full-fat dairy products like cheese in moderation to manage cholesterol.

Unsaturated fats, both monounsaturated and polyunsaturated, help lower bad LDL cholesterol when used to replace saturated and trans fats in your diet. Omega-3 polyunsaturated fats also help lower triglycerides.