TUESDAY, July 1, (News Locale) - Doctors always say that high levels of "good" cholesterol or high density lipoproteins (HDL) are good for your heart.. Now a new study by European researchers has linked high HDL levels to better memory in old age. 

Researchers at the French National Institute for Health and Medical Research (INSERM) and the University College London analyzed the cholesterol levels of 3,673 participants who took part in Whitehall II study. The study started in 1985 and involves over 10,000 British civil servants working in London.

The blood-fat and memory data collected in 1995 and 2002 of Whitehall II study were examined by the researchers. At these times the study was in phase 5 and phase 7  when the average ages of the study participants were 55 and 61 years.

At 55 years researchers found that participants with low HDL cholesterol had a 27 percent increased risk of memory loss when compared to those with high or normal HDL. In 2002 when the participants were aged 61 years, with low HDL had a 53 percent increased risk of memory loss compared to participants with high or normal HDL levels.

For study purposes, low HDL was defined as less than 40 mg/dL and high HDL as 60 mg/dL or higher. In the five years between the two phases, participants with decreasing HDL levels had a 61 percent increased risk of decline in their ability to remember words as compared to those with high HDL.

Overall cholesterol levels were not found to have any link with memory decline. Furthermore researchers did not find gender differences when they looked at low HDH levels and memory loss.

Reporting in the July 1 issue of Arteriosclerosis, Thrombosis and Vascular Biology, the researchers theorized that HDL may affect memory through its influence on atherosclerotic disease and stroke, or vascular injury as well as anti-inflammatory and antioxidant effects.

According to the American Medical Association, "Experts think that HDL tends to carry cholesterol away from the arteries and back to the liver, where it's passed from the body. Some experts believe that HDL removes excess cholesterol from arterial plaque, slowing its buildup."

More often than not we hear doctors asking patients to ensure they keep LDL or bad cholesterol levels under control. The above study though points to the fact that maintaining good cholesterol or HDL levels may be equally important.