Does low LDL cholesterol shorten lifespan? | Dr. Thomas Dayspring | The Proof Clips EP 251

Episode Overview

• The episode addresses the common claim, based on some observational studies, that low LDL cholesterol is associated with higher mortality.
• Dr. Thomas Dayspring debunks this claim by explaining the concept of "reverse causation," where serious underlying diseases cause both low LDL levels and increased mortality.
• He clarifies the distinction between cholesterol circulating in the blood and the cholesterol used by the body's cells and brain, which produce their own supply.
• The discussion highlights that clinical trials using medications to drastically lower LDL have not shown any adverse effects or increased mortality, contradicting the misleading observational data.

Key Concepts

• Reverse Causation: The core concept used to explain the link between low LDL and mortality. It posits that an underlying illness (e.g., cancer, malnutrition) is the true cause of both the low LDL cholesterol and the increased risk of death, not that the low LDL itself is harmful.
• Observational Studies vs. Clinical Trials: The discussion contrasts the findings of observational studies, which can only show association and are prone to confounding factors like reverse causation, with clinical trials where LDL is pharmacologically lowered, which have shown no increase in mortality.
• Cholesterol Pools: Dr. Dayspring explains that the cholesterol circulating in the blood (as LDL) is a separate "pool" from the cholesterol that is within our cells or brain. Cells and the brain can produce their own cholesterol and do not depend on the supply from circulating LDL.

Quotes

• At 00:06 - "Low LDL cholesterol is associated with higher mortality. This is again something that I see LDL cholesterol sort of denialists point to." - Host Simon Hill sets up the question by referencing a common argument used to downplay the dangers of high LDL.
• At 00:45 - "It's not lack of circulating cholesterol in the blood... The amount of cholesterol circulating in your blood, that's one pool of the body's cholesterol... and that pool of cholesterol has no relationship whatsoever to the pool of cholesterol that are in our cells." - Dr. Thomas Dayspring explains that blood cholesterol levels do not affect the cholesterol supply needed for essential cellular functions.
• At 1:16 - "We certainly know in all the trials we have where we use pharmacologic agents to blow away ApoB and LDL cholesterol to levels as low as 10 or 20 milligrams per deciliter, there has been no adversity in those trials." - Dr. Dayspring provides evidence from clinical trials to counter the idea that very low LDL levels are inherently dangerous.

Takeaways

• Be cautious when interpreting observational data that links low LDL to higher mortality, as this is likely due to reverse causation where an underlying disease is the true culprit.
• Understand that your body's cells and brain produce the cholesterol they need locally; they are not dependent on the level of LDL cholesterol circulating in your bloodstream for their function.
• Evidence from clinical trials shows that pharmacologically lowering LDL cholesterol to very low levels is safe and does not increase mortality, reinforcing that the goal should be to lower atherogenic lipoproteins to reduce cardiovascular risk.