NEW YORK (Reuters Health) – Low levels of HDL cholesterol, the “good” cholesterol, are associated with poor short-term memory in middle-aged adults, new findings indicate.

According to researcher Dr. Archana Singh-Manoux at INSERM and Hopital Paul Brousse, Paris and colleagues at University College London, HDL cholesterol is an important brain compound and is thought to possess anti-inflammatory and antioxidant properties.

The researchers examined the relationship between blood fats and memory using data on 3673 individuals, who were an average of 55 years old when tested between 1997 and 1999.

Short-term verbal memory was assessed at the outset with a 20-word free recall test. Memory deficit was defined as recalling no more than four words. Memory decline was defined as a reduction of two or more words between the first test and a second test, performed in 2002-2004.

The results are reported in the medical journal Arteriosclerosis, Thrombosis and Vascular Biology.

Compared with a high HDL level, low HDL was associated with memory deficit during both tests. After adjusting for sociodemographic factors, illnesses, and medication use, those with low HDL were 27 percent and 53 percent more likely to have a memory deficit on the first and second test, respectively.

A decrease in HDL cholesterol between the first and second test was associated with a 61 percent increased likelihood of a decline in memory

“Our findings on individuals aged 55 and 61 at the two phases of data collection suggest that low levels of HDL cholesterol may be an important risk factor” for memory loss, Singh-Manoux and colleagues conclude.

An editorial on the study says that, although it is “tempting” to speculate that raising HDL would improve memory, “we should remain extremely cautious when proposing therapeutic intervention on the basis of observation studies.”

SOURCE: Arteriosclerosis, Thrombosis and Vascular Biology, online July 1, 2008.