Memory Defects and Lipids

A report online in the journal Arteriosclerosis, Thrombosis and Vascular Biology has raised a lot of questions about memory and lipid levels. The subjects were some 3,700 participants in the 10,000-strong Whitehall II study of UK government workers; 27% of them were women. They had their serum lipids (total cholesterol, high density lipoprotein, triglycerides) measured and underwent a battery of memory tests twice, at a 5-year interval. Their average age at the first exam was 55, and at the second, 61 years. Before analysis, the findings were adjusted for education level, occupational position, coronary heart disease, stroke, high blood pressure, medication use, diabetes, smoking, and alcohol use.

At average age 55, those subjects with a low HDL-C (the ‘good’ cholesterol) had a 27% increased risk of memory loss, compared to those with a high HDL-C.

At average age 61, a low HDL-C was linked to a 53% increased risk of memory loss.

And during the 5-year interval between the two exams subjects with decreasing HDL-C levels had a 61% increased risk in their word memory ability.

There were no differences between men and women in these findings, and total cholesterol and triglycerides were without influence on memory. Statin use didn’t make any difference to the findings, either.

The role of HDL-C is to help clear excess cholesterol from the blood, help nerve cell junctions (synapses) to mature, and slows development of beta amyloid (the major component of the plaques found in Alzheimer brains). So there’s reason to believe that the findings from this study are relevant. But, an editorial in the same journal warns “It is tempting to speculate that increasing levels of HDL-C, or ‘good cholesterol’ might protect our memories. However, unfortunate results in large intervention trials with dietary antioxidants suggest we should remain cautious . . .”

However, there are other good reasons to keep your HDL-C at an above-average level. If you are having trouble doing this, see your family physician.