Study Identifies 7 Preventable Risk Factors of Alzheimer's Disease

According to a recent study performed by researchers at the University of California, San Francisco (UCSF), roughly half of Alzheimer's disease cases have the potential to be reduced if people focused on seven preventable risk factors.

It is estimated that 33.9 million individuals globally live with Alzheimer's disease, but according to the researchers, that number could be decreased by 3 million if there was a 25% reduction in all seven of these risk factors. A reduction of 10% in these seven factors could prevent 1.1 million cases, they said.

The researchers advised that people:

1. Quit smoking

2. Increase physical activity

3. Boost mental activity

4. Control blood pressure

5. Manage diabetes

6. Keep obesity in check

7. Handle depression

"Given the current absence of disease-modifying treatments, as well as increasing awareness that symptoms develop over many years or even decades, there has been growing interest in identification of effective strategies for prevention of [Alzheimer's disease], wrote Deborah Barnes and Kristine Yaffe, researchers at UCSF.

The rate of Alzheimer’s cases globally is expected to triple over the next forty years as the “Baby Boomer” generation reaches the retirement age.

The authors of this study evaluated prior research which focused on factors that predispose people to developing Alzheimer's. The researchers categorized seven factors that were most likely within an individual’s power to control and affect.

The study showed that the factor which affects the largest population of Alzheimer's cases (19% of instances, or 6.5 million cases worldwide) was "low educational attainment,” which the researchers identified as not completing higher education, having a low IQ, or not participating in mentally stimulating leisure time activities.

The factor which was held responsible for the second-highest number of cases was smoking, which the study found plays a role in 14% of cases, or 4.7 million cases worldwide.

Physical inactivity was found to be responsible for 13% of global instances and was the third-largest factor, but was identified as the highest contributor to cases is the United States, contributing to 21%, or 1.1 million cases.

"What really mattered was how common the risk factors were in the population. In the U.S.A., about a third of the population is sedentary, so a large number of Alzheimer's cases are potentially attributable to physical inactivity," reported Barnes, a professor of psychiatry at UCSF.

"Worldwide, low education was more important, because so many people throughout the world are illiterate or are not educated beyond elementary school," Barnes continued. "Smoking also contributed to a large percentage of cases because it is unfortunately still really common."

According to the researchers, the results of this study imply that quitting smoking as well as increasing physical activity levels throughout life have the potential to dramatically decrease the number of Alzheimer's cases.

Other experts, however, pointed out that while these seven factors could contribute to the development of Alzheimer's, none of them have been found to cause the disease.

Researchers Laura Fratiglioni, from the Karolinska Institute in Sweden, and Chengxuan Qiu, from the Stockholm Gerontology Research Center, wrote: "Accumulated evidence from epidemiological research strongly supports a role for lifestyle and cardiovascular risk factors in the pathogenesis and development of dementia. However, none of these factors has been proven to have a causal relation specifically with [Alzheimer's disease].”

Fratiglioni and Qiu both agreed, though, that the findings suggest "that preventive and therapeutic interventions have great potential," and that interventions should be carried out in high-risk populations.

The results of the study were presented on July 20^th at The Alzheimer's Association 2011 International Conference on Alzheimer's Disease (ICAD), held in Paris.

The study was published online in the journal The Lancet Neurology.