Fluctuating cholesterol: Causes and links to dementia

Forever it seemed that the only things concerning the medical community about cholesterol were high levels and an inconsistent link to heart disease.

But quite a bit of research over the last couple of decades has uncovered cholesterol’s significant role in brain health…

For starters, cholesterol makes up the majority of myelin, a fatty coating on neurons to facilitate the brain’s processing speed. Cholesterol is also necessary for communication between neurotransmitters like dopamine and serotonin.

And a growing body of research appears to imply that what’s deemed best for the heart may not be best for the brain…

One study found lowering cholesterol levels may impair brain function. In another, a long-term increase in cholesterol is associated with better cognitive function. And yet another cites evidence that different statins are able to lower brain cholesterol — which is not the cholesterol the drugs were designed to go after.

Now researchers have found a similar connection between fluctuating cholesterol levels and dementia risk. You may be wondering what could possibly cause cholesterol to fluctuate. You’ll be surprised at what I’ve uncovered…

But first, let’s see how researchers at the Mayo Clinic came to their conclusion after a 13-year study.

Fluctuating cholesterol and dementia risk

Using healthcare data, the research team identified 11,571 people aged 60 or older who did not have a prior diagnosis of Alzheimer’s disease or dementia.

They then looked at these participants’ total cholesterol levels, as well as their triglyceride, LDL and HDL levels. They determined their baselines using measurements that were taken on three different days during a five-year span prior to their study period.

For the study itself, the researchers divided participants into five equal groups based on how much these measurements had fluctuated over time. The “lowest” group had the least variation over time and the “highest” group had the most variation.

Participants were then followed for an average of thirteen years. During that time, 2,473 people developed Alzheimer’s disease or another form of dementia.

When it came to total cholesterol, participants with the highest variation had a 19 percent increased risk of dementia compared to those in the group with the least variation. Of the 2,311 people in the highest group, 515 developed dementia compared to 483 of the 2,311 people in the lowest group.

For triglycerides, those in the highest group had a 23 percent increased risk. Researchers did not find a link between variations in LDL and HDL and an increased risk of dementia.

What causes fluctuating cholesterol?

Surprisingly, research has shown that cholesterol and triglyceride levels may vary significantly based on the season of the year.

For example, one study found that LDL (“bad” cholesterol) increased an average of 7mg/dl during the winter, while during the summer months, HDL (“good” cholesterol) and triglycerides were nine and five percent higher, respectively.

Of course, seasonal changes to our bodies are not really under our control. But studies have identified other factors that make our cholesterol levels fluctuate that we can control.

Take Fasting. Short-term fasting can be a good way to cleanse the body of toxins. But be aware that it can also cause changes in your cholesterol levels.

In one study, serum cholesterol levels rose almost 10 mg/dL after a 24-hour fast, with LDLs rising as much as 23 mg/dL.

Certain medical conditions can also raise cholesterol levels, even while on statins, including those having to do with the thyroid, liver or kidneys.

Some causes of cholesterol fluctuations may be within your control, including:

• High caffeine consumption – drinking 4+ cups of coffee per day can cause a spike in cholesterol levels.
• Smoking
• Losing weight quickly by eating a very low-calorie diet can lead to a temporary spike in LDL cholesterol.
• Certain medications can affect lipid metabolism and thus increase cholesterol. They include:
  • Anti-hypertension drugs, including beta-blockers
  • Retinoid medications used to treat acne
  • Birth control pills
  • Anticonvulsants
  • Immunosuppressants
  • Danazol (a synthetic steroid)

Of course, statin medications lower cholesterol levels, but experts say that even while taking them, levels can vary daily between eight and 15 percent. Use of some statins has already been associated with significant dementia risk.

The bottom line

It’s important to realize that the association between fluctuating cholesterol and dementia risk is only that. However, it’s important to consider those previous studies I mentioned early that also found associations between cholesterol levels and brain function.

Hopefully, further research will make it commonplace for physicians to consider the harms of these fluctuations instead of only focusing on lowering levels.

Sources:

Fluctuating levels of cholesterol and triglycerides linked to increased risk of dementia — Science Daily

Association Between Fluctuations in Blood Lipid Levels Over Time With Incident Alzheimer Disease and Alzheimer Disease Related Dementias — Neurology

Cholesterol Levels Rise After a 24-Hour Fast — HCPLive

What Can Cause a Sudden Increase in Cholesterol? — Buzz Rx

Cholesterol Levels Rise, Fall with Changing Seasons — American College of Cardiology

When Statins Don’t Work — WebMD