In middle-aged and older adults in China who aren’t at high risk for heart disease, having either too low or too high 'bad' cholesterol (LDL) is linked to a higher chance of dying from any cause or heart problems — the safest zone seems to be around 106 to 118 mg/dL.

What we've found so far is that the evidence we've reviewed leans toward a U-shaped link between LDL cholesterol levels and death risk in middle-aged to older adults in China who have low or primary heart disease risk. This means both very low and very high LDL levels may be tied to higher risks, while moderate levels appear more favorable. Our analysis of the available research shows that in this group, having LDL cholesterol that is either too low or too high is associated with a greater chance of dying from any cause or from heart-related issues [1]. The range where risk appears lowest falls between 106 and 118 mg/dL [1]. This pattern suggests that extremely low LDL levels are not necessarily better, at least in this population and risk category. We base this on one assertion drawn from 59.0 supporting studies, with no studies refuting the idea [1]. While the number of supporting studies is high, we are looking at only one distinct claim. That means our current analysis captures a consistent signal across many studies but is still limited in scope—focusing on a specific group in China with low or primary heart disease risk. We don’t yet know if this U-shaped pattern applies to other populations or age groups. Also, we can’t say from this evidence what causes the increased risk—only that a link exists. We’re also not able to determine whether changing LDL levels would change risk. The takeaway: For middle-aged and older adults in China who aren’t at high heart disease risk, aiming for an LDL level in the range of about 106–118 mg/dL may be linked to the lowest risk of death. Going too far below or above that range may not be ideal. But we’re still building our understanding, and this is just one piece of a larger puzzle.