Cholesterol-lowering drugs or statins usually used to prevent heart attacks and strokes may be the key to slow down age-related memory loss and dementia as well, according to a study published in the July 29 issue of Neurology.

More exactly, a study involving 1,674 elderly people showed that those taking cholesterol-lowering drugs were about half as likely to develop dementia over five years of follow-up compared to those who did not.

The participants aged 60 and older were dementia and Alzheimer’s-free at the beginning of the trial. Of them, 27 percent took cholesterol-lowering drugs at any time during the study. In total, 130 participants developed dementia by the end of five years. However, once the researchers had taken account of other risk factors such as level of education, smoking, and diabetes, they discovered that those taking statins had an approximately 50 percent lower risk of developing dementia.

“The bottom line is that if a person takes statins over a course of about five to seven years, it reduces the risk of dementia by half, and that’s a really big change,” Mary N. Haan, DrPH, of the University of Michigan School of Public Health, lead author of the study, said.

Although the study does not prove how exactly cholesterol-lowering drugs influence the brains of the elderly people, it is a great step forward in understanding Alzheimer’s disease and in finding treatments for delaying the its devastating symptoms.

“We aren’t suggesting that people could take statins to prevent cognitive decline if they don’t need them for other reasons. But we need a trial designed to determine if statins really do reduce the risk of dementia and Alzheimer’s disease,” Dr. Haan said.

Whether or not statins helps preventing dementia has been the subject of investigation for years, but none of the previous studies has had such good results as the one conducted by Dr. Haan. Now what researchers need to do is to solve the mystery beyond use of statins and dementia in order to find better treatment for the disease.

One theory promoted by Dr. Haan in understanding how exactly statins help is that these drugs keep the blood vessels healthy and blood flowing freely to the brain. It is known that a decreased supply of blood to the brain is a major factor promoting the development of dementia.

Another theory would be that cardiovascular disease and diabetes, two conditions for which statins are required, could further lead to dementia. That’s why Dr. Haan suggested that researchers should focus more on people having these two conditions and their risk of developing Alzheimer’s.

It is the more important to follow people with cardiovascular disease, as a separate study, presented during the 2008 Alzheimer's Association International Conference on Alzheimer's Disease in Chicago, suggested that angiotensin, a drug used to reduce blood pressure can also cut dementia’s risk.

Researchers at the Boston University School of Medicine analyzed records of about 6 million people treated for high blood pressure between 2001 and 2006 and found that those taking angiotensin receptor blockers (ARBs) were less likely over that period to be diagnosed with dementia compared with those on other blood pressure medication such as ACE inhibitors. Overall, the study revealed that they were 45 percent less likely to go on to develop delirium, be admitted to a nursing home, or die prematurely.

“High blood pressure doubles the risk of Alzheimer's disease and increases risk of stroke - this study highlights that it is becoming increasingly important to investigate blood pressure lowering drugs as a potential treatment for dementia,” Professor Clive Ballard, from the Alzheimer’s Society said about the findings.

Findings ways to cure Alzheimer’s is a top priority for researchers, as the number of patients with this condition is going to quadruple worldwide by 2050 reaching approximately 106 million cases. There are currently five drugs approved to treat Alzheimer’s, but they only mask symptoms for 6 to 12 months at most, according to the Alzheimer’s Association, an advocacy group based in Chicago.