The lead author of the new study is Séverine Sabia, of the department of Epidemiology of Ageing and Neurodegenerative Diseases at Inserm, a public research institution affiliated with the Université de Paris in France.
Sabia and her colleagues set out to examine the link between the American Heart Association’s (AHA) guidelines for optimal cardiovascular health — which they dub “Life’s Simple 7” — and the risk of developing dementia later in life.
“Life’s Simple 7” are modifiable risk factors which, according to the AHA, can help keep heart disease at bay.
Making lifestyle changes along these seven parameters can improve a person’s cardiovascular health, the AHA advises. Life’s Simple 7 are:
- manage blood pressure
- manage cholesterol
- lower blood sugar
- stay physically active
- follow a healthful diet
- lose weight
- stop smoking (or don’t start)
In the new research, Sabia and her team looked at how well people adhered to these steps at 50 years of age. They also examined the link with dementia over the following 25 years. The research team published its findings in The BMJ.
Studying heart health and dementia risk
As the authors note in their paper, previous studies have already pointed to Life’s Simple 7 as potential guidelines for preserving brain health into older age. However, the existing evidence has so far been inconclusive.
So, for the current study, Sabia and team examined data on 7,899 participants who were 50-year old British men and women. All of the individuals had taken part in the Whitehall II Study — an analysis of sociobehavioral factors on long term health.
At the start of the study, the participants were in perfect cardiovascular health and did not have dementia. The Whitehall II Study started in 1985–1988 and Sabia and team followed the dementia cases through to 2017.
Over the average follow-up period of 25 years, 347 of the 7,899 participants developed dementia at an average of 75 years old.
The researchers measured the adherence to the seven parameters by using a three point score for each of them.
In total, the “cardiovascular health score was the sum of seven metrics (score range 0–14), and the researchers categorized these into poor (scores 0–6), intermediate (7–11), and optimal (12–14) cardiovascular health.”
A healthy heart may keep the brain healthy
After adjusting for potential confounders, the research revealed that a high adherence score to the seven cardiovascular parameters correlated with a lower risk of dementia later.
Specifically, in the group with a poor cardiovascular score, dementia occurred at a rate of 3.2 cases per 1,000 person years.
In the group with an intermediate cardiovascular score, the rate was 1.8 per 1,000 person years, while only 1.3 cases of dementia occurred per 1,000 person years among those who scored the highest.
Importantly, higher adherence to Life’s Simple 7 at 50 years of age also correlated with a higher brain volume and higher grey matter volume at the average age of 70 years, as MRI scans reflected.
However, the study is observational and cannot establish causality. The participants also reported their own adherence to the cardiovascular parameters, which may have increased bias.
Nevertheless, “Our findings suggest that the Life’s Simple 7, which comprises the cardiovascular health score, at age 50 may shape the risk of dementia in a synergistic manner,” write the authors.
“Cardiovascular risk factors are modifiable, making them strategically important prevention targets,” add Sabia and colleagues, concluding:
“This study supports public health policies to improve cardiovascular health as early as age 50 to promote cognitive health.”
