Smoking a factor in increased midlife mental decline risk

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People’s thinking skills may be at higher risk of declining in midlife if they smoke or have high blood pressure or diabetes, suggests a new study led by researchers at the University of California, San Francisco, and published in the journal Neurology.

The study authors noted that heart disease risk factors – especially high blood pressure and diabetes – have become more common in midlife, according to a HealthDay report on 25 July 2020.

“We found those two risk factors, as well as smoking, are associated with higher odds of having accelerated cognitive [mental] decline, even over just a short span of five years,” said lead author Dr Kristine Yaffe, a professor of psychiatry, neurology and epidemiology.

"It's encouraging to know that there are behaviours people can modify in midlife to help prevent the steepest declines in thinking and memory as they age,” she said in a news release from the American Academy of Neurology.

Study findings

For the study, Yaffe's team collected data on nearly 2,700 people, average age 50, whose memory and thinking were tested at the study's start and five years later.

After five years, 5% had mental decline, including 7.5% of people with high blood pressure, 10% of those with diabetes and nearly 8% of smokers.

After age, race, education and other factors were considered, smokers were 65% more likely to have accelerated mental decline. Those with high blood pressure were 87% more likely and those with diabetes had nearly triple the risk, the researchers said.

"Surprisingly, people who were considered obese and those with high cholesterol did not have a greater risk of cognitive decline," Yaffe said.

People who had one or two of the risk factors were nearly twice as likely as those with none to have midlife mental decline. Three or more risk factors nearly tripled the risk, the findings showed.

"Most public health prevention efforts focus on older adults, but our study suggests the need to look at cognitive performance across a person's life span," Yaffe said.

"Middle-aged adults who have one or more cardiovascular risk factors like smoking, high blood pressure and diabetes may be people we should be monitoring and educating on healthy lifestyle choices earlier in life."


Cardiovascular Risk Factors and Accelerated Cognitive Decline in Midlife: the CARDIA Study

Neurology. Published ahead of print on 15 July 2020


Kristine Yaffe, Amber L Bahorik, Tina D Hoang, Sarah Forrester, David R Jacobs, Cora E Lewis, Donald M Lloyd-Hones, Stephen Sidney and Jared Reis.

The authors are from the University of California, San Francisco; San Francisco VA Medical Center; Northern California Institute Research for Research and Education; University of Massachusetts; University of Minnesota; University of Alabama at Birmingham; Northwestern University, Chicago; Kaiser Permanente Northern California; and National Heart, Lung, and Blood Institute, Bethesda.

Increasing evidence supports an association between midlife cardiovascular risk

factors (CVRFs) and risk of dementia, but less is known about whether CVRFs influence cognition in midlife. We examined the relationship between CVRFs and midlife cognitive decline.

In 2675 black and white, middle-aged adults (mean age: 50.2±3.6, 57% female, 45% black), we measured CVRFs at baseline: hypertension (31%), diabetes (11%), obesity (43%), high cholesterol (9%), and current cigarette smoking (15%), and administered cognitive tests of memory, executive function and processing speed at baseline and five years later.

Using logistic regression, we estimated the association of CVRFs with accelerated decline (race-specific decline ≥1.5 SD from the mean change) on a composite cognitive score.


Five percent (n=143) of participants had accelerated cognitive decline over 5 years. Smoking, hypertension, and diabetes were associated with increased likelihood of accelerated decline after multivariable adjustment (AOR=1.65, 95% CI 1.00-2.71; AOR=1.87, 95% CI 1.26- 2.75; AOR=2.45, 95% CI 1.54-3.88, respectively) while obesity and high cholesterol were not associated with risk of decline.

These results were similar when stratified by race. The likelihood of accelerated decline also increased with greater number of CVRFs: 1-2 CVRFs AOR=1.77, 95% CI 1.02-3.05; ≥3 CVRFs AOR=2.94, 95% CI 1.64-5.28) and with Framingham Coronary Heart Disease Risk Score≥10 (AOR=2.29, 95% CI 1.21-4.34).


Midlife CVRFs, especially hypertension, diabetes and smoking, are common and associated with accelerated cognitive decline at midlife. These results identify potential modifiable targets to prevent midlife cognitive decline and highlight the need for a life course approach to cognitive function and aging.


Smoking, heart disease increase midlife mental decline risk


Cardiovascular Risk Factors and Accelerated Cognitive Decline in Midlife: the CARDIA Study




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