Avoiding 3 Risk Factors In Midlife Could Add 13 Dementia-Free Years

In the new study, researchers analyzed data in the Atherosclerosis Risk in Communities (ARIC) study, a cohort study that began in 1987.

They examined the data of 12,409 participants. They assessed three risk factors, which the ARIC study consistently measured:

• high blood pressure (hypertension)
• smoking
• diabetes.

Participants were followed over a median of 26.3 years. In that time:

• 3,008 people developed dementia
• 5,238 people died without developing dementia.

Individuals with no risk factors for dementia had the lowest risk of developing the condition. In contrast, those with all three risk factors were 2.69 times more likely to develop dementia.

The study also found that taking care of vascular health in midlife could help protect against dementia for an additional 12.6 years. Diabetes, hypertension, and smoking are all risk factors for vascular disease.

Dung Trinh, MD, an internist at the MemorialCare Medical Group and Chief Medical Officer of Healthy Brain Clinic in Irvine, CA, spoke to Medical News Today about these findings.

“I find the results compelling because they reinforce the close connection between cardiovascular health and brain health during midlife,” Trinh, who was not involved in the study, said. “High blood pressure, diabetes, and smoking can damage blood vessels, increase inflammation, and reduce the brain’s resilience over time.”

However, Trinh also explained that: “This was an observational study, so it cannot prove that avoiding these conditions will give an individual exactly 13 additional dementia-free years. The figure compares people with none of the three risk factors with those who had all three, and ‘dementia-free survival’ reflects both the timing of dementia and overall longevity.”

The researchers identified certain demographic differences.

For example, Black people were more likely to develop dementia sooner than white participants.

People who carried the apolipoprotein E4 (APOE-e4) gene were also at risk of developing dementia earlier than people who did not carry the gene. The APOE-e4 gene is a known risk factor for cognitive decline.

The findings also suggested that women typically lived longer without dementia than men. Josef Coresh, MD, PhD, senior investigator of the study, discussed this with MNT.

“Much of that difference reflects lower mortality rather than lower dementia risk. With three risk factors, women averaged 18.1 dementia-free years versus 16.6 for men,” Coresh said.

“But because women survive into the ages where dementia risk is highest, their lifetime dementia risk is higher — about 40% versus 33% in our data. It’s the same pattern as our main finding: The added years are added at the oldest ages, which is the highest-risk period,” he explained.

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Diabetes, hypertension, and smoking are not the only risk factors for dementia.

Coresh described other factors that are important to consider:

“The other five components of Life’s Essential 8Trusted Source — physical activity, diet, sleep, body weight, cholesterol. Beyond that, the 2024 Lancet Commission identifies 14 modifiable factorsTrusted Source accounting for about 45% of dementia, and several are late-life targets: hearing loss, vision, social isolation, depression. Education and cognitive engagement matter as well.”

Trinh explained that, while “nonmodifiable risk factors such as age, genetics, and family history” can increase the risk of dementia, there are numerous modifiable risk factors, or factors that are capable of being changed or prevented.

He advised that, “rather than focusing on one isolated behavior, the strongest prevention approach is to address a person’s combined vascular, lifestyle, sensory, social, and environmental risks across the life course.”

The study authors determined that better vascular health in midlife was linked with longer dementia-free survival.

While it may not be possible to completely prevent dementia, taking steps to improve vascular health could help reduce the risk or delay its onset.

Steps that may help include:

• getting enough regular physical activity or exercise
• working with a healthcare professional to manage conditions such as diabetes, hypertension, high cholesterol, depression and other mental health problems
• getting regular hearing checks and treating any hearing loss
• avoiding or quitting smoking
• avoiding or limiting alcohol consumption
• getting enough quality sleep
• staying mentally active, such as with brain exercises.

Coresh recommended aiming to manage risk factors “as early as possible.”

“Know your blood pressure and A1c by your 40s, and aim to prevent rather than only treat: physical activity, lower salt intake, and weight control keep blood pressure from rising in the first place,” he advised.

“Timing matters for diabetes in particular — diabetes diagnosed before 60 carries substantially more dementia risk than diabetes appearing at 65, so delaying onset has value beyond good control. And avoid smoking,” Coresh stressed.

Trinh added that “the central message should be one of opportunity rather than certainty or blame: Dementia risk can often be reduced, but it cannot be eliminated, and people who develop dementia should not be assumed to have caused their condition.”

He concluded:

“Healthy choices also depend on access to primary care, affordable medication, nutritious food, safe places to exercise, smoking-cessation services, and equitable treatment of vascular disease. It is also important to note that this study examined dementia broadly, not biologically confirmed Alzheimer’s disease specifically. Its greatest value is in showing that protecting the heart and blood vessels during midlife may help people preserve both longevity and cognitive health.”