Healthier hearts and cardiovascular systems are considered to be the primary reasons for declines in dementia over the last 30 years. That's the conclusion of new research published in the New England Journal of Medicine, which reports a decline in dementia among the study participants in the Framingham Heart Study that has been underway since 1948.

This project looked at 5,205 participants over the age of 60 and analyzed factors related to dementia. The team, led by Claudia L. Satizabal, Ph.D., from the Boston University School of Medicine, acknowledged that factors other than improvements in cardiovascular functions may have also contributed to the decline.

While dementia is on the decline, the risk for obesity and diabetes has increased over the last 30 years, with 25 percent of those over the age of 65 having diabetes, much of it undiagnosed. The study indicated a decline in other cardiovascular risks including stroke, atrial fibrillation and heart failure. The researchers reported their data indicated a twofold percentage rate of decline from the initial study period beginning in the first decade of data to the last decade of a data.

One critical variable contributing to the lower rate of dementia was education. The decline in rates of dementia were only for participants having a high school education or even further education. Low education has been shown to be risk factor for age-related dementia both internationally and in the United States.

The study researchers are hesitant to draw broad conclusions, offering these comments: "Our study offers cautious hope that some cases of dementia might be preventable or at least delayed. However, it also emphasizes our incomplete understanding of the observed temporal trend and the need for further exploration of factors that contribute to this decline in order to better understand and possibly accelerate this beneficial trend."

Reductions in any form of dementia are critical from an international public health perspective. The global rate of dementia among older adults from all causes is estimated to be between 5 and 7 percent. Other studies have demonstrated a decline in dementia related to cardiovascular disease.

However, the rate of dementia secondary to Alzheimer's disease is not reported to be on the decline. Dementia associated with Alzheimer's disease accounts for 60 to 80 percent of the diagnosed dementias, and the incidence varies across races with elderly Hispanics and African-Americans having a higher rate of Alzheimer's-related dementia than Caucasians. Variations in health, socioeconomic and lifestyle risks are considered to be factors contributing to a higher rate among some groups.

So consider this: A lifestyle that contributes to a healthier heart and cardiovascular system is good for your brain. While a healthy routine may not totally prevent cognitive decline and dementia in later life, it will reap benefits in lowering the risk.