Put simply, triglycerides are a form of fat and LDL is a form of cholesterol. Both come from your diet and are made in your liver. In normal amounts, both play important roles in keeping your body healthy, but in excess, both can have harmful effects. High blood levels of both triglycerides and LDL cholesterol are associated with an increased risk of developing coronary artery disease. A high-fat or high-sugar diet can raise your blood levels of both triglycerides and LDL cholesterol, as can some medical conditions and medications.
LDL stands for low-density lipoprotein, a packaged mix of fat and protein that attaches to cholesterol and carries it through your bloodstream to different parts of your body. There are several types of lipoproteins, but LDL is considered the most dangerous to your health. When there is more LDL cholesterol than your body can use, it stays in your blood and you are said to have high cholesterol levels. High LDL cholesterol levels are associated with clogged arteries that can lead to heart attack or stroke. This is why LDL is considered a bad form of cholesterol.
Triglycerides that come from the food you eat are broken down during digestion and then repackaged for absorption into your bloodstream. Your liver also produces triglycerides from excess sugar and protein in your diet. As triglycerides move through your bloodstream, they are used for energy, stored as body fat or combined with cholesterol and protein to form various types of lipoprotein packages.
Two normal and important functions of triglycerides in the body are to provide structure to cell membranes and form the lipoprotein packages that carry cholesterol throughout the body. The LDL package delivers cholesterol to various organs and glands, where it is used primarily to make hormones. (See References 1, page 1, References 2 and 3)
You may be able to maintain lower blood levels of triglycerides and LDL by eating fewer foods that contain saturated fat and cholesterol, such as meats and whole-milk dairy products, and more foods that are high in fiber, such as such as legumes, fruits, vegetable and grains. Eating less refined sugar and other sweeteners, drinking less alcohol, eating fewer calories overall to lose weight, if necessary, and increasing the amount of salmon, tuna and other oily fish you eat, can help reduce triglyceride levels. If your LDL and triglyceride levels are especially high, you will probably have to take medication to get them down. If a blood test shows that you have high LDL or triglyceride levels, discuss your options with your doctor.
Molly McAdams is a writer who lives in New York City. She has covered health and lifestyle for various print and online publishers since 1989. She holds a Master of Science degree in nutrition.