Roller-coaster levels of "bad" cholesterol may lead to poorer mental performance in older adults, a study has found.
Greater fluctuations in low-density lipoprotein (LDL), which is linked to heart disease, were associated with lower scores in mental ability tests.
Participants with the highest LDL variability took 2.7 seconds longer on average than those with the lowest to finish one test that deliberately confused words and colours.
The test involved naming the ink colours of words describing a different colour - for instance, the word blue written in red.
Lead researcher Dr Roelof Smit, from Leiden University Medical Centre in the Netherlands, said: "While this might seem like a small effect, it is significant at a population level.
"Our findings suggest for the first time that it's not just the average level of your LDL-cholesterol that is related to brain health, but also how much your levels vary from one measurement to another."
A total of 4428 people aged 70 to 82 from Scotland, Ireland and the Netherlands took part in the Prosper study. All either had pre-existing artery disease or were at high risk of developing the condition.
More LDL variability was also associated with lower brain blood flow and bright areas showing up on brain scans which have been linked to blood vessel dysfunction.
The findings are reported in the American Heart Association journal Circulation.
