What Science Says about the Link between Blood Pressure Control and Dementia
There is growing scientific consensus that uncontrolled, elevated blood pressure, especially in mid-life, increases the likelihood of cognitive decline, including dementia, in later life. After nearly 15 years on an upward trend, awareness among Americans about high blood pressure and how to control and treat it is now on the decline [ref]. Even with the help of blood pressure medications, some groups—including older adults, Black people, and uninsured Americans—are less likely than they were in earlier years to adequately control their blood pressure.
The state of the science connecting vascular risk factors to dementia and cognitive decline has substantially matured in the last 5 to 10 years.
In 2019, two major publications were published from the SPRINT-MIND clinical research study, which is the first interventional trial of its size and scope to examine a modifiable risk factor for dementia. The study established that intensively lowering blood pressure in participants aged 50 and above decreased their risk for mild cognitive impairment by approximately 20% and reduced progression of white matter hyperintensities, which are associated with vascular damage in the brain.
In 2017, the NIH/National Institute on Aging (NIA) sponsored an in-depth, systematic review of interventions and approaches to prevent dementia. The U.S. National Academy of Science, Engineering, and Medicine (NASEM) concluded that there was encouraging but inconsistent evidence that blood pressure control was effective in preventing dementia. The NASEM report states:
“The available evidence, together with the strong evidence for blood pressure management in preventing stroke and cardiovascular disease and the relative benefit/risk ratio of antihypertensive medications and lifestyle interventions, is sufficient to justify communication with the public regarding the use of blood pressure management, particularly during midlife, for preventing, delaying, and slowing clinical Alzheimer’s-type dementia.”
Shortly after the NASEM report, the British medical journal, The Lancet, reported results from its own review of the evidence-base for dementia prevention, intervention, and care. The Lancet Commission found that the state of available evidence strongly supported blood pressure and other modifiable risk factor interventions for dementia. They concluded:
“Be ambitious about prevention: We recommend active treatment of hypertension in middle aged (45–65 years) and older people (aged older than 65 years) without dementia to reduce dementia incidence.”
A 2019 meta-analysis conducted in part by NIA researchers similarly concluded:
“We have provided some evidence that using any anti-hypertensive medication in people aged 55 years and older with high blood pressure reduced the risk for developing dementia with no significant differences by use of a specific drug class. This finding suggests that treating high blood pressure could be an immediately accessible primary strategy to reduce the incidence of dementia and use of specific medicines should follow current guidelines.”
Improving Population Blood Pressure Control for Brain and Heart Health (2015). In this Executive Perspective article, the Center for Disease Control and Prevention’s (CDC’s) Division for Heart Disease and Stroke Prevention discusses opportunities for improving brain health and preventing cognitive decline by controlling hypertension and other cardiovascular risk factors throughout the life course.
Hundreds of other recent advances from basic, clinical, and epidemiological research point in the same direction and suggest that reducing vascular risk factors in mid-life should have a moderate, if not strong, impact on dementia prevalence and severity, both at the patient and population health level.
Potential Impact of Enhancing Blood Pressure Control Is Immense
High blood pressure is estimated to cost the US about $131 billion each year [ref].
According to the CDC, nearly half of all adults in the United States (108 million people) have hypertension, and even worse, only about 1 in 4 of them have their blood pressure under control [ref].
Fortunately, several drugs including antihypertensives, either alone or in combination with diet and exercise, are very effective at controlling and lowering blood pressure. However, only half of US adults (30 million) who should be taking medication to control their blood pressure either have not been prescribed or have not taken any medication [ref].
Individuals are often not aware that they have high blood pressure, and lack of awareness has gotten worse in recent years. In 1999-2000, just 70% of participants in one large study showed an awareness of their condition. That number increased steadily to 85% in 2013-2014, but declined to 77% in 2017-2018 [ref].
“One in three cases of dementia could potentially be prevented if brain health is improved throughout life (2017 Lancet Commission).”
In 2022, an estimated 6.5 million Americans age 65 and older are living with Alzheimer’s dementia, and by 2050, the number of people age 65 and older with Alzheimer's dementia is projected to reach 12.7 million (2022 Alzheimer's Disease Facts and Figures).
The World Health Organization estimates that there are about 50 million people living with dementia globally, and the number of people affected is set to triple to 150 million by 2050, with the largest increases expected in low and middle-income countries.
Estimates suggest that the cost of dementia in the U.S. is $818 billion a year, equivalent to 1.1% of global gross domestic product—a cost that has grown by 35% since 2010. By 2030, the global cost of dementia could grow to $2 trillion a year, which could overwhelm health and social care systems [ref].
Importance of Health Disparities and Inequities in Hypertension and Dementia
CDC data indicate that Black Americans ages 35-64 years old are 50% more likely to have high blood pressure than are White Americans (ref) and also less likely to have their hypertension under control (ref).
According to the CDC’s Alzheimer’s Disease and Healthy Aging Data Portal, 15.7% of Black, non-Hispanic older adults reported subjective cognitive decline or memory loss compared to 9.6% of White, non-Hispanic older adults. Moreover, 40.6% of Black, non-Hispanic older adults with cognitive decline reported discussing it with a healthcare professional compared to 47.1% of White, non-Hispanic older adults [ref].
One study estimated that while 20% of Americans with dementia are Black, they bear 33% of its national cost [ref].
In the NINDS-funded epidemiologic study REGARDS, researchers report that vascular risk factors—high blood pressure, poor diet, and lack of exercise—are more prevalent in the southeastern U.S. (aka the “Stroke Belt”) vs. the rest of the U.S. regardless of race and ethnicity, but also even more prevalent in Black Americans than White Americans [ref]. REGARDS researchers also reported that Black people, when compared to White people, had faster declines in global cognition associated with systolic blood pressure and mean arterial pressure [ref].
Less than 5% of dementia clinical trial participants are not White [ref].
What’s Next: The Research Continues
There are more than a dozen ongoing interventional studies aimed at assessing vascular-related approaches to treating or preventing dementia, several of which are funded by NIH. Interventions being studied include antihypertensives, blood vessel dilators, statins, and behavioral training for improved blood pressure control. A number of these studies are assessing multi-component interventions which combine blood pressure reduction with diet, exercise, and other behavioral approaches. For more information, see NIA’s webpage on AD clinical trials.
Several NIH-funded large prospective cohorts will continue to examine the link between dementia and blood pressure as well as other modifiable risk factors (e.g., other vascular and lifestyle factors). See this report for a list of relevant cohorts which are examining vascular contributions to cognitive impairment and dementia as well as this interactive tool.
As new evidence accumulates from these studies, NIH will continue to refine its public health messaging.
Key References on Blood Pressure and Cognitive Decline:
Muntner P, Hardy ST, Fine LJ, et al. “Trends in Blood Pressure Control Among US Adults With Hypertension, 1999-2000 to 2017-2018.” JAMA. Published online September 09, 2020. doi:10.1001/jama.2020.14545
SPRINT MIND Investigators for the SPRINT Research Group, et al. “Effect of Intensive vs Standard Blood Pressure Control on Probable Dementia: A Randomized Clinical Trial.” JAMA, vol. 321, no. 6, 2019, pp. 553–61, doi:10.1001/jama.2018.21442.
SPRINT MIND Investigators for the SPRINT Research Group, et al. “Association of Intensive vs Standard Blood Pressure Control with Cerebral White Matter Lesions.” JAMA, vol. 322, no. 6, Aug. 2019, p. 524, doi:10.1001/jama.2019.10551.
National Academies of Sciences, Engineering, and Medicine. “Preventing Cognitive Decline and Dementia: A Way Forward.” Preventing Cognitive Decline and Dementia, National Academies Press, 5 Sept. 2017, doi:10.17226/24782.
Lancet Commission: Livingston, Gill, et al. “Dementia Prevention, Intervention, and Care.” The Lancet, vol. 390, no. 10113, Lancet Publishing Group, 16 Dec. 2017, pp. 2673–734, doi:10.1016/S0140-6736(17)31363-6.
Ding, Jie, et al. “Antihypertensive Medications and Risk for Incident Dementia and Alzheimer’s Disease: A Meta-Analysis of Individual Participant Data from Prospective Cohort Studies.” The Lancet Neurology, vol. 19, no. 1, Jan. 2020, pp. 61–70, doi:10.1016/S1474-4422(19)30393-X.
Levine, D., et al. “Blood Pressure and Cognitive Decline Over 8 Years in Middle-Aged and Older Black and White Americans.” Hypertension. 2019 Feb;73(2):310-318.DOI: 10.1161/HYPERTENSIONAHA.118.12062
Gottesman RF, Albert MS, et al. “Associations Between Midlife Vascular Risk Factors and 25-Year Incident Dementia in the Atherosclerosis Risk in Communities (ARIC) Cohort.” JAMA Neurol. 2017 Oct 1;74(10):1246-1254. doi: 10.1001/jamaneurol.2017.1658.
Yano Y, Griswold M, et al. “Long-Term Blood Pressure Level and Variability From Midlife to Later Life and Subsequent Cognitive Change: The ARIC Neurocognitive Study.” J Am Heart Assoc. 2018Aug 7;7(15):e009578. doi: 10.1161/JAHA.118.009578.
Norton, Sam, et al. “Potential for Primary Prevention of Alzheimer’s Disease: An Analysis of Population-Based Data.” The Lancet Neurology, vol. 13, no. 8, Aug. 2014, pp. 788–94, doi:10.1016/S1474-4422(14)70136-X.