Low Density Lipoproteins:
Are They ALL Bad for You?
What are
low density lipoproteins?
LDLs are macromolecules made in the liver and used to transport cholesterol in the blood. They're less dense than HDLs -- and therefore theoretically more liable to get stuck in places like crevices in the arteries. Are all LDLs the same?No. In fact, some researchers believe that a special sub class of LDLs, known as
very low density lipoproteins (VLDLs)
, may be far better indicators of health problems. What are the recommended guidelines for healthy LDL levels? The American Heart Association recommends the following: - Less than 100 milligrams per DL is considered excellent.
- Between 100 and 189 milligrams per DL is considered okay.
- Above 190 milligrams per DL is considered potentially indicative of increased risk for heart disease and atherosclerosis.
Why are high LDL levels considered to be bad for you? During the 1950s and 1960s, influential researchers, such as Ancel Keys, became obsessed with the notion that dietary fat and cholesterol caused obesity and heart disease. Although the evidence supporting this hypothesis was far from complete, these influential researchers managed to convince their peers of their point of view. Nevertheless, subsequent studies attempting to correlate elevated LDL levels with increased risk for diseases like atherosclerosis and CAD have yielded mixed results. One reason why this may be so is that many studies have not discriminated between VLDLs and LDLs.What are generally recommended ways to lower LDL levels? - Medications -- One class of drug in particular, known as statins, seems to do well at lowering LDL levels by chemically inhibiting their production in the liver.
- Niacin -- Evidence exists to suggest that taking niacin supplements might help lower levels.
- Ketogenic diet -- People who go on what are known as ketogenic diets, such as the Atkins diet, may see reductions in their LDL levels -- particularly their VLDL levels.
- Avoiding spikes in insulin -- Insulin acts on an enzyme called HMG-CoA reductase, which drives the production of LDLs in the liver. Therefore, some have argued that taking steps to lower insulin levels can improve LDL profiles.
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