(February 22, 2008 - Insidermedicine) More Americans are remaining mentally sharp into old age, according to research published in the online issue of the journal Alzheimer's and Dementia.

Here are some facts about cognitive impairment in old age:

•    Cognitive impairment refers to a range of conditions affecting intellectual functioning and mental acuity, such as memory loss, dementia, and Alzheimer's disease.

•    Several lifestyle habits and medical conditions are known to increase the chance of a person developing cognitive impairment, including high blood pressure, high cholesterol, and smoking.

•    Some good ways to reduce your risk of developing cognitive impairment as you age include staying physically active, taking any medication you have been prescribed for high cholesterol or blood pressure, and “exercising” your brain with activities like doing crossword puzzles and taking classes.

Researchers from the University of Michigan Medical School collected data from the Health and Retirement Study (HRS) on the cognitive health and other characteristics of 11,000 seniors living in the United States.

In 1993, 12.2% of the study participants over the age of 70 had cognitive impairment, compared with only 8.7% in 2002. While this drop seems small, it represents superior mental clarity for hundreds of thousands of seniors. The authors estimate that about 40% of the change in cognitive status seen between 1993 and 2003 could be attributed to improvements in education and wealth.

Based on these findings, the authors conclude that more American seniors are hanging onto their mental acuity, at least in part because education and personal wealth have also improved in these individuals. They also suggest that improvements in care for health conditions that can affect cognitive impairment have contributed to this improvement.

For Insidermedicine in Depth, I'm Dr. Susan Sharma.