(CNN) — Avoiding three health factors may delay the odds of developing dementia by about 13 years, a new study has found: type 2 diabetes, smoking and high blood pressure.
Scientific research has long established that these risk factors are three of the strongest for dementia, and that the neurodegenerative disease’s development begins long before symptoms arrive, said Dr. Josef Coresh, senior author of the study that published Wednesday in the journal Neurology Open Access. But Coresh’s new study of more than 12,400 adults quantified how much the combination of these vascular measures in middle age may have influenced when dementia began to set in.
Participants who had those three health hazards when they were, on average, about age 56 were more than twice as likely to develop dementia and more than five times as likely to die prematurely from another cause.
“That’s relatively easy for clinicians to discuss and patients to understand,” said Coresh, founding director of the Optimal Aging Institute at the NYU Grossman School of Medicine. For patients, knowing how many more “good years” they can get by making certain lifestyle changes can be more motivating than simply knowing a percentage risk for dementia, Coresh added.
The study only shows an association, not causation, especially since researchers measured participants for high blood pressure, diabetes, smoking and other health factors such as weight just once before following them for a median period of about 26 years. Although brain health was assessed multiple times until 2022 at the latest, many other factors could have changed during that time.
“View the results as an important estimate rather than the exact prediction for every individual,” said Dr. Sanjula Singh, an assistant professor in neurology at Harvard Medical School in Boston, who wasn’t involved in the study.
Cardiologist Dr. Andrew Freeman said the research, which he wasn’t involved in, is “really exciting, and yet it also still calls to action that we need to do a lot more to get people living healthily.”
“One of the things that we’re starting to see a lot of is this concept of health span versus lifespan,” Freeman, director of cardiovascular prevention and wellness at National Jewish Health in Denver, said. “It’s one thing to be alive; it’s another to be alive and well and to avoid the American curse, which is working hard your whole life, saving your money, retiring and then suffering heart attacks, strokes, dementia.”
Lowering your risk for dementia
If you have high blood pressure or type 2 diabetes or want to quit smoking, talk to your doctor, Coresh said.
Hypertension and diabetes share some risk factors, including physical inactivity, obesity, poor diet, alcohol intake and smoking, experts said. Accordingly, preventing or alleviating hypertension and diabetes can partly be done by managing these factors. A lower-fat, plant-based diet such as the DASH (Dietary Approaches to Stop Hypertension) diet can work wonders, Freeman said.
You can view the World Health Organization’s recommendations for exercise here. Ensuring you get enough sleep and manage stress is also important.
“The way we live has the most profound impact, and I’m talking about a magnitude that is unachievable by any medication,” Freeman added. About 45% of dementia cases are due to modifiable risk factors, said Singh, also principal investigator at the Brain Care Labs and Global Brain Care Coalition at Massachusetts General Hospital.
When it comes to smoking, quitting must be your own desire for it to be effective, Freeman said. “Once you buy in, there’s a lot of different ways that can help,” he added — including nicotine patches, exercise, lozenges and gums, several medications, therapeutic programs, and acupuncture.
Also remember that smoking is a habit with certain reinforcements and associations, so you may need to also switch up your routine and social circle for at least six months to boost your chances of quitting, Freeman said.
Highlighting more tangible odds
The adults in the new research are from the Atherosclerosis Risk in Communities cohort study, which has followed nearly 15,800 adults from four communities in the United States since the late 1980s, when participants were between ages 45 and 65. The areas were Forsyth County, North Carolina; Jackson, Mississippi; eight northwestern suburbs of Minneapolis, Minnesota; and Washington County, Maryland. Fifty-six percent of participants in the latest research were women.
Having none of the three risk factors was linked with 30.1 dementia-free years, compared with 17.5 years among those who had the three health risks — hence the nearly 13-year potential delay in risk if participants had managed those health measures.
Women were dementia-free slightly longer than men, and Black participants developed dementia a few years sooner than their White counterparts. By age 85, only 7% of the adults with three risk factors remained dementia-free, compared with 35% of those with no risk factors.
The less healthy participants had a higher body mass index and prevalence of stroke, and lower physical activity and educational attainment. They were also more likely to be Black — potentially explaining the fewer dementia-free years in this group — and to be carriers of the APOE ε4 gene, which is the strongest genetic risk factor for Alzheimer’s disease, the most common form of dementia.
Over time, the three components of concern “can damage blood vessels throughout the body, including those that supply the brain, reducing the delivery of oxygen and nutrients and increasing the risk of stroke and small vessel disease,” Dr. Jacqui Hanley, head of research funding at Alzheimer’s Research UK, said in a statement.
“This damage can make the brain more vulnerable to cognitive decline and dementia,” added Hanley, who wasn’t involved in the study.
Brain health and habits are built from many small, consistent choices over time, Singh said. “Set the goals for yourself. Find friends or family members to keep you accountable or to work out with together.”
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