We hear a lot about cholesterol when it comes to our health—good cholesterol, bad cholesterol, high cholesterol, and cholesterol in food. And understanding cholesterol can be confusing since there are two types: dietary cholesterol and serum cholesterol. Dietary cholesterol is found in the food we eat, while serum cholesterol naturally exists in our blood, and can rise to an unhealthy level leading to clogged arteries and heart disease. Serum cholesterol is made up of high-density lipoprotein (HDL), the good cholesterol, and low-density lipoprotein (LDL), the bad cholesterol.
Cholesterol is a fat-like substance that is carried through the blood by something called lipoproteins. Your body needs some cholesterol to make certain hormones, vitamin D, and for healthy digestion, but too much can be detrimental to your health as high levels of cholesterol raises your risk of heart disease.
Your total cholesterol consists of three parts: high-density lipoprotein (HDL), low-density lipoprotein (LDL), and triglycerides. The HDL is considered good cholesterol because these lipoproteins protect against a heart attack by carrying the bad cholesterol—the LDL, which contributes to fatty buildups in the arteries—away from the arteries and back to the liver where it is broken down and expelled from the body. So high levels of HDL and low levels of LDL are good, while low levels of HDL and high levels of LDL are bad.
Triglycerides are a type of fat in our bodies. Extra calories that your body doesn't use are converted into triglycerides and stored to use later. A combination of high triglycerides with low HDL and high LDL can lead to fatty buildups in the walls of the arteries, which can lead to a heart attack or stroke.
Dietary cholesterol is found in animal-based products including meat, fish, eggs, as well as poultry and dairy. Red meat will have more cholesterol than chicken and fish, but shrimp and eggs have been known to be the worst cholesterol culprits of the group. However, although one serving of shrimp and egg each contains roughly 200 milligrams of cholesterol (two-thirds of the recommended daily serving), it has been found that the health benefits and low saturated fat in both shrimp and eggs outweigh the high cholesterol levels.
A Rockefeller University study showed that a diet of shrimp raised the good cholesterol (HDL) and lowered triglycerides (fatty acids) significantly. Researchers at Harvard Medical School discovered that eggs are not a factor in increasing our chances of heart disease due to their low concentration of saturated fat—only 1 1/2 grams. Of course, it is always recommended to eat these foods in moderation.
Cholesterol in Our Diet
While a diet high in dietary cholesterol can lead to high serum cholesterol in some people, studies have shown that limiting dietary cholesterol may not be nearly as important as limiting dietary saturated fats and trans fats when it comes to preventing heart-related diseases.
Dietary cholesterol does not necessarily add more calories to a diet (cholesterol does not provide any calories); however, those foods high in dietary cholesterol are also likely to be high in fat and calories, so avoiding foods high in cholesterol means that you are also avoiding foods with a high calorie count.
Lucky for us, most low-calorie recipes automatically use ingredients that are naturally low in cholesterol. Oftentimes foods that are high in cholesterol are also high in fats, namely full-fat dairy and meats that are high in dangerous saturated fats. Thus, you won't find ingredients high in cholesterol in low-calorie recipes.
So how much dietary cholesterol should you consume in a day? Well, professionals in the medical field have suggested an amount of less than 300 mg per day for good health. While different individual bodies seem to react differently to the amount of dietary cholesterol consumed (some are more sensitive than others to higher levels of dietary cholesterol), limiting overall cholesterol intake–and especially overall fat and saturated fat intake–appears to be the best combination for health.