Weighing the Risks of Dementia
Photo by Eric Prouzet on Unsplash
If you believe life begins at conception, then consider me a native of Chicago. That’s where a young married couple who were about to become my parents were living when I was conceived. Once they learned they were expecting, however, the couple high-tailed it back to Louisiana, where both were from, and where I was born. By relocating, the couple unknowingly gifted me with an extra risk factor for dementia.
Yes! According to an extensive study published in December by the Rand Corporation, being born in the South is a risk factor for Alzheimer’s and cognitive decline. “Individuals who were born in the South face statistically significantly higher chances of developing dementia, even when controlling for many other factors,” the report states. The authors’ explanation is “possibly because the quality of Education is lower in Southern states than in the rest of the country.” I haven’t seen the latest rankings to verify that, but it is generally understood in the South that the primary purpose of schooling is to nurture talent for Southeastern Conference football teams.
The Rand study was designed to figure out which among 181 potential risk factors were the best predictors of cognitive impairment and dementia 20 years later. The strongest predictors, it turns out, are an individual’s baseline cognitive abilities, their health, and their functional limitations. People who at age 60 were in poor physical health, had suffered a Stroke, had lower cognitive abilities, and had functional limitations and certain genes were most likely to have dementia by age 80. Other strong risk factors were never having worked, having Diabetes, having a body mass index of 35 or more, never drinking alcohol or drinking excessively, never exercising, having low engagement in hobbies and novel information activities, and not having a private health insurance plan.
On the other hand, the weakest indicators were parents’ health, family size, marital history, and demographics. Given that my mother developed Alzheimer’s, I worry that it might be hereditary. Based on this study, however, I am more confident that my mother’s lack of Exercise, social isolation, lack of hobbies, hypertension, and fondness for sweets were more decisive factors than any gene she transmitted.
Lowering Risk
What the Rand study also does is support previous research showing that up to half of the risk factors for dementia are totally within our control. They are tied to Lifestyle decisions, and changing them significantly lowers the chances of experiencing dementia. According to the Lancet Commission on Dementia Prevention, Intervention and Care, there are 14 modifiable risk factors:
Untreated vision loss
Untreated hearing loss
Obesity
Diabetes
High LDL (bad) cholesterol
Hypertension
Physical inactivity
Smoking
Lack of education
Social isolation
Excessive alcohol consumption
Head injury
Air pollution
To that list, Emily and Mitchell Clionsky, the authors of Dementia Prevention, add several other changes that can modify risk: Getting adequate Sleep and treating sleep apnea, avoiding cannabis, and avoiding certain prescription medicines (including anti-Anxiety drugs) and over-the-counter sleep aids.
“Regardless of your genetic inheritance,” Mitchell Clionsky says, “large population studies tell us if we really do maximize all the preventive things we can, we have a chance to reduce the risk of getting dementia by 50%.”
The greatest single risk factor for dementia, however, is age. Only 2 out of 100 people aged 65 to 69 have dementia. The risk roughly doubles for every five years after that. Among people who live into their 90s, 33 out of 100 have dementia.
But that’s a risk factor we’ll just have to live with.
