Study: Dementia risk factors, such as obesity, now more common among adults

May 9 (UPI) -- Up to 18% of adults in the United States meet the criteria for obesity, or being severely overweight, in their 40s or 50s, placing them at high risk for dementia, a study published Monday found.

In addition, up to 12% engage in lower-than-recommended levels of physical activity or have "low educational attainment," meaning they did not finish high school and or attend college, the data published Monday by JAMA Neurology showed.

As many as 10% had Type 2 diabetes were current smokers, the researchers said.

These "modifiable" risk factors, or those related to a person's lifestyle choices, also place them at increased risk for Alzheimer's disease or another form of dementia, according to the researchers.

Black Americans, as well as American Indians and Alaska Natives with these modifiable risk factors, were at higher risk for developing Alzheimer's disease or dementia compared with White Americans who have them, the researchers said.

Men of all races and ethnicities with these risk factors have a higher risk for dementia than women who have them, they said.

The findings suggest a change in the prevalence of modifiable risk factors for dementia among adults in the United States over the past decade, according to researchers.

In a similar study published 10 years ago, the same team of researchers found that physical inactivity, depression and smoking were the most common modifiable dementia risk factors among adults nationally.

"The modifiable risk factors for Alzheimer's disease and dementias have changed over the past decade ... [from] physical inactivity, depression and smoking ... [to] midlife obesity, physical inactivity and low education," study co-author Dr. Roch A. Nianogo told UPI in an email.

"Our study suggests that these risk factors seem to differ by sex and race and ethnicity," said Nianogo, an assistant professor of epidemiology at the UCLA Fielding School of Public Health in Los Angeles.

About one in three cases of Alzheimer's disease and related dementias is associated with eight modifiable risk factors, such as obesity, or being severely overweight, or lack of physical activity, Nianogo and his colleagues estimated.

About 6 million people in the United States have been diagnosed with dementia, or declining brain function, including memory loss, according to the Alzheimer's Association.

Previous studies have suggested that the risk factors for heart disease -- including smoking, being overweight or obese and have Type 2 diabetes -- also may apply to dementia.

This is significant, given that 40% of adults nationally meet the criteria for obesity while some 30 million have Type 2 diabetes, based on Centers for Disease Control and Prevention.

The agency recommends that adults engage in some form of physical activity for at least 150 minutes per week in order to maintain a healthy weight.

In addition, Black, Hispanic and Asian Americans may be at higher risk for dementia compared with White Americans, according to earlier research.

"Our study suggests that people may be able to reduce their risk of developing dementia through a healthy lifestyle," study co-author Deborah Barnes told UPI in an email.

"Things like physical inactivity, diabetes, hypertension, smoking and obesity are linked to heart disease, and we know that what is good for the heart is generally also good for the brain," said Barnes, a professor of psychiatry at the University of California-San Francisco.