When we talk about cholesterol, the conversation almost always turns to heart disease; arteries clogging up like rush hour traffic, leading to heart attacks and strokes. But what if I told you that cholesterol is also tangled up in the fate of your brain? That’s right: this greasy little molecule may not just determine whether you live long enough to forget your car keys, but also whether you remember what a car key is in the first place.
Cholesterol and dementia: The unexpected link
At the American Heart Association’s 2024 Scientific Sessions, a team of researchers presented findings that might make you rethink your relationship with cholesterol. They tracked nearly 10,000 adults in their 70s and found a disturbing trend:
- People whose cholesterol levels bounced around wildly from year to year faced a significantly higher risk of dementia or cognitive decline.
- The most erratic cholesterol patterns were linked to a 60% jump in dementia risk and a 23% increase in cognitive decline.
In other words, it’s not just how high your cholesterol is, it’s how stable it stays over time that matters.
Why cholesterol fluctuations might be dangerous
Dr. Zhen Zhou, the lead researcher, has a theory. These unpredictable changes in cholesterol levels could destabilise the fatty plaques that build up in your arteries, a process that’s already known to be bad for your heart. When these plaques become unstable, they might also impair blood flow to the brain, and that’s when the trouble starts.
The LDL factor: Another piece of the puzzle
Adding more fuel to the fire, the Lancet Commission recently declared high LDL cholesterol – the so-called “bad” cholesterol – as a newly recognised risk factor for dementia. This fits with previous research linking high cholesterol in midlife to cognitive decline in the golden years.
But it’s not as simple as “LDL bad, lower better.” A landmark 32-year study published in 2010 found something counterintuitive:
- Having high cholesterol in midlife wasn’t necessarily a surefire predictor of dementia.
- What did raise red flags was a sharp drop in cholesterol levels between middle and late life, which correlated with higher dementia risk.
It’s enough to make you wonder whether the conventional wisdom on cholesterol has missed a critical point.
What can you do about it?
So where does that leave us? Here’s a game plan for keeping both your heart and mind in good working order:
- Monitor your cholesterol: Don’t just check your levels once and call it a day. Keep track of trends over time, especially large fluctuations.
- Eat real food: Avoid the usual ultra-processed suspects and focus on whole, unprocessed foods; vegetables, nuts, healthy fats, and quality proteins.
- Exercise smartly: Regular physical activity helps stabilise cholesterol levels and improves cardiovascular health.
- Consider medication thoughtfully: If your doctor prescribes cholesterol-lowering drugs, make sure you understand why, and whether the benefits outweigh the risks.
- Keep the whole picture in mind: Blood pressure, blood sugar, and inflammation all play roles in brain and heart health. They’re part of the same metabolic puzzle.
What we still don’t know
The relationship between cholesterol and dementia is complicated, and plenty of questions remain unanswered. Why do cholesterol levels sometimes drop before the onset of dementia? Is it a cause or a symptom? And how much does diet, exercise, and medication actually influence long-term brain health?
One thing is clear: by managing your cholesterol wisely, keeping it stable rather than obsessing over driving it to the lowest possible number, you might just be doing your brain a favour.
In the end, the story of cholesterol isn’t just about heart attacks and statins. It’s about the intersection of two organs that define who we are and how long we get to stay that way. And that, I’d argue, is worth paying attention to.
