New Study Finds That Cholesterol & Triglyceride Levels Might Help Predict Your Risk for Dementia—Here's What to Know
This study is another reminder that brain health and cardiovascular health are linked!
Reviewed by Dietitian Jessica Ball, M.S., RD
We know that yo-yo dieting and frequent blood sugar roller coasters do a number on our bodies. This week, we're learning more about the potential health harms related to fluctuations of another health factor: cholesterol.
According to a study published July 5, 2023 in the journal Neurology, individuals who have high variability in their total cholesterol and triglyceride levels—meaning large changes throughout the lifespan—appear to be at higher risk for developing dementia later in life compared to their more steady-cholesterol peers.
Read on to learn more about how the scientists came to this conclusion, then score tips about how to keep your cholesterol levels in check—and steady on the low end.
Related: Does Inflammation Cause High Cholesterol?
What This Dementia Study Found
As we speak, 55 million people on Earth are living with dementia, according to World Health Organization estimates. The Alzheimer's Association predicts that this figure will skyrocket by 2050, to the tune of 152 million as our average population age increases.
Since this is the case, researchers and doctors are hot on the case of potential risk factors for cognitive decline—and potential ways to tackle them early so we can prevent or delay as many dementia or Alzheimer's disease diagnoses as possible. (ICYMI, Alzheimer's is a specific form of dementia, and actually is the most common cause of dementia. Dementia is a general term of cognitive decline severe enough to significantly impact daily functioning, says the Alzheimer's Association.)
Cholesterol is a type of fat that's pumped out by the liver to be used to create cells and hormones, and triglycerides are one type of cholesterol that's used for energy. Earlier research has hinted that there may be a link between cholesterol variation and dementia, and we're still learning more about if high "bad" (LDL) cholesterol has a direct link to increased dementia risk. In other words, the connection between cholesterol and cognitive decline is still a bit fuzzy, so this study set out to add to our collective pile of evidence.
The researchers gathered 11,571 participants with an average age of 71. Slightly more than half (54%) identified as female. At the outset of the study, none had been diagnosed with dementia or Alzheimer's disease.
Within 5 years of the start of the study, each individual had their cholesterol measured at least three times. These tests tracked total, triglycerides, LDL and HDL—here's a refresher on what these blood levels mean. For the next 13 years, the researchers followed these people; 2,473 of which developed some type of dementia.
To determine if cholesterol changes appeared to have any link with dementia risk, the scientists categorized the participants into five groups based on how much their cholesterol fluctuated between readings.
Those who fell into the top 20% of total cholesterol variations were 19% more likely to receive a dementia diagnosis by the follow-up time than those who were in the bottom 20%. A similar story tracked among those who ranked among the top 20% in triglyceride variability; these people were 23% more likely to develop dementia compared to the individuals in the bottom 20%. Fluctuations in LDL and HDL didn't appear to have a direct connection to dementia risk.
These results held true even after the researchers adjusted for other potential personal and health metrics, such as education level and baseline cholesterol.
The scientists believe this correlation may be true because cholesterol may lead to inflammation in blood vessels within the brain, which may impede the brain cells' ability to transport nutrients and "clean out the trash" (AKA waste products).
Related: 5 Habits to Break to Lower Cholesterol
The Bottom Line
A new study suggests that big changes in total cholesterol and triglycerides may be related to higher risk for dementia. The results cannot certify cause and effect, however.
More research is needed among large populations and for longer periods of time that takes into account genetic risk factors for dementia, the researchers admit. Plus, we have yet to confirm if those in the early stages of dementia might make lifestyle choices that lead to the sharp changes in their total cholesterol and triglycerides.
If this fluctuation factor and dementia risk connection holds up in future research, it's important to keep these findings in context—and consider the potential real world implications and action steps. We know a lot about the foods that boost your "good" (HDL) cholesterol, foods that lower "bad" (LDL) cholesterol and are fairly well-versed in other ways to lower cholesterol naturally like moving more, managing stress and moderating alcohol intake. However, we don't know much (yet) about how to reduce cholesterol and triglyceride fluctuations…besides just always keeping cholesterol levels on the low side. (Well, and HDL on the higher side.)
Until we know more, it appears pretty clear that lower cholesterol is linked with lower risk for Alzheimer's disease, so it certainly can't hurt to:
Talk to your doctor about a cholesterol test if you haven't had one recently
Incorporate meals from this low cholesterol diet plan for beginners into your diet, and aim to reduce consumption of saturated fats
Shoot for at least 30 minutes of physical activity 5 days each week (our best walking plan to help lower your cholesterol levels is a great place to start)
Drink alcohol in moderation
Carve out time for meditation or other stress-relieving strategies
Ask your doctor if there are any lifestyle factors you should consider to support healthier cholesterol levels
