Lowering bad cholesterol really aggressively might not help people live longer because while it prevents heart attacks, it could also cause other problems that balance things out.

Lowering bad cholesterol really aggressively helps prevent heart attacks and strokes in people who already have heart disease, but it doesn’t actually help them live longer — which scientists call the 'cholesterol mortality paradox'.

If you have high 'bad' cholesterol, lowering it more aggressively can help you live longer, especially if your levels are really high to begin with. Doctors should decide how hard to treat based on how high your cholesterol is and your overall heart risk.

If your 'bad' cholesterol is 100 or higher, lowering it more aggressively helps prevent heart-related deaths. But if it's already below 100, lowering it even more doesn't seem to help much — there might be a cutoff where treatment stops adding extra benefit.

If you've already had heart problems, keeping your 'bad' cholesterol really low—below 55—might help prevent future heart attacks or strokes compared to aiming for a higher level.

For people who already have heart disease, aiming to get their 'bad' cholesterol (LDL) below 55 mg/dL cuts their risk of serious heart problems by about one-third over three years compared to aiming for below 70 mg/dL — and it doesn’t seem to cause more side effects.