Can Exercise and Lower Blood Pressure Protect Memory? A 2-Year Trial
TL;DR: The rrAD trial randomized 513 adults aged 60 to 85 to two years of supervised aerobic exercise, intensive blood pressure and cholesterol lowering, both, or usual care. Memory and thinking scores rose slightly in every group, and neither exercise nor intensive risk reduction produced a statistically significant extra gain. That is not proof that exercise or blood pressure control are useless for the brain. It shows that in already fairly healthy, well-treated older adults, two years is too short to see a clear cognitive difference.
Table of Contents
- Why This Study Matters
- The Study: Who, What, How
- What the Numbers Show
- What This Means for You (And What It Doesn’t)
- How This Fits With the Broader Evidence
- FAQ
- Conclusion
- References
Why This Study Matters
Physical inactivity, high blood pressure and high LDL cholesterol all sit on the standard lists of modifiable risk factors for dementia. The logic is simple. The brain is one of the most blood-hungry organs in the body, and the same damage that narrows arteries in the heart also affects the small vessels that feed brain tissue. Fix the vessels, the thinking goes, and you protect memory.
The problem is that most of the evidence behind that idea comes from observational studies. People who exercise and keep their blood pressure low tend to have better cognition later in life, but they also tend to be wealthier, better educated, and healthier in a dozen other ways. Randomized trials, where chance decides who gets the intervention, are the only clean way to test cause and effect. And until recently, nobody had tested the obvious combination: what happens if you give older adults a serious exercise program and push their blood pressure and cholesterol down hard at the same time?
That is the question the rrAD trial (Risk Reduction for Alzheimer’s Disease) was designed to answer. Led by Rong Zhang, a professor of neurology at UT Southwestern Medical Center, with sites at the University of Kansas Medical Center and other US centers, it ran for two years per participant and was published in JAMA Neurology in 2026. The answer was not what most people expected.
The Study: Who, What, How
rrAD used a 2 x 2 factorial design. That means each participant was randomly assigned, in equal proportions, to one of four groups, which lets researchers test two interventions in one trial: the effect of exercise (comparing everyone who exercised with everyone who did not) and the effect of intensive vascular risk reduction (comparing everyone who got it with everyone who did not).
| Parameter | Detail |
|---|---|
| Study design | Single-blind, multicenter randomized clinical trial, 2 x 2 factorial, 4 US sites |
| Sample size | 3,290 screened, 513 randomized, 443 completed the 24-month visit, 480 in the primary analysis |
| Participants | Aged 60 to 85, no dementia, with hypertension, a family history of dementia and/or self-reported cognitive decline; mean age 68.7, 63.0% women |
| Groups | Aerobic exercise; intensive vascular risk reduction (IRVR); IRVR plus exercise; usual care |
| Duration | 24 months per participant; enrollment February 2017, last visit January 2022 |
| Primary endpoint | Change in the Preclinical Alzheimer Cognitive Composite (PACC) score at 24 months |
| Secondary endpoints | NIH Toolbox Cognition Battery fluid composite and individual test scores |
| Registration | ClinicalTrials.gov NCT02913664 |
The exercise arm was not a token effort. According to the trial registration, participants started with supervised moderate to vigorous aerobic training 3 times a week for about 30 minutes, then built up over 4 to 5 months to 4 to 5 sessions a week of 40 to 50 minutes. They held that level for the rest of the two years. That is at or above the 150 minutes a week most public health guidelines recommend.
The risk reduction arm was aggressive too. The goal was a systolic blood pressure below 130 mm Hg, using losartan and amlodipine (with additional drugs if needed), plus atorvastatin 80 mg daily to lower LDL cholesterol. That is the top dose of one of the most widely used statins.
One detail matters a lot: the groups that did not get aerobic exercise were not sedentary controls. The registration describes home-based stretching for the IRVR group and the usual care group, building up to 4 to 5 times a week, with encouragement to attend monthly stretching classes. Usual care participants also kept seeing their own doctors for blood pressure and cholesterol management. In other words, the comparison group was getting attention, structure, regular contact and standard medical care.
What the Numbers Show
The PACC is a composite of memory and thinking tests built to pick up the earliest, subtle changes that precede Alzheimer’s disease. Higher is better. Here is what happened over 24 months, taken directly from the published abstract:
| Comparison | Change in PACC at 24 months | Difference |
|---|---|---|
| No exercise vs. exercise | +0.2 (95% CI 0.1 to 0.3) vs. +0.3 (95% CI 0.2 to 0.4) | 0.1 units (95% CI -0.1 to 0.2), P = .37 |
| No IRVR vs. IRVR | +0.3 (95% CI 0.2 to 0.4) vs. +0.2 (95% CI 0.1 to 0.3) | 0.1 units in favor of no IRVR (95% CI -0.3 to 0.03), P = .12 |
| Group by time interaction (all four arms) | Not statistically significant | P = .13 |
Three things stand out. First, scores went up in every group. Nobody declined on average. Part of that is a practice effect (people get better at tests they take repeatedly), and part is probably that everyone in the trial, including usual care, was being looked after. Second, the exercise group gained 0.1 units more than the non-exercise group, but the confidence interval crosses zero, so this could easily be chance. Third, the intensive risk reduction group actually gained slightly less, again without statistical significance.
The secondary outcomes told the same story. In the authors’ words, increases in the NIH Toolbox composite and individual test scores “showed similar results.” Their conclusion was blunt: exercise, IRVR, or both “did not result in statistically significant differences in improvements in cognitive function over 24 months.”
What This Means for You (And What It Doesn’t)
It would be easy to read this as “exercise doesn’t help your brain, and blood pressure pills are pointless for memory.” That is not what the trial showed. Here is a more careful reading.
1. A null result over two years is not the same as no effect over twenty. Dementia develops over decades. The participants had no dementia at the start, and their scores were rising. Detecting a protective effect in a group that is not declining is very hard. The PACC was designed to be sensitive, but two years in healthy-ish 68-year-olds may simply be too short a window.
2. The control group was not doing nothing. Stretching several times a week, monthly classes, regular study visits and standard medical care is a reasonable lifestyle in itself. The trial compared “very active plus intensive treatment” against “moderately looked after,” not against true inactivity. If you are currently sedentary with untreated high blood pressure, your starting point is different from that of anyone in this trial.
3. The reasons to exercise and control blood pressure do not depend on this trial. Aerobic training lowers cardiovascular risk, improves fitness and supports independence in older age. Blood pressure control lowers the risk of stroke and heart failure. Stroke itself is a major cause of cognitive decline. None of that is touched by a 24-month cognitive test result.
4. What the trial does argue against is the promise that a fixed program will make you measurably sharper within a year or two. If someone sells an exercise or supplement routine with a “boost your memory in weeks” claim, rrAD is a useful reality check.
Practically, the sensible move is the boring one: know your blood pressure, treat it if it is high, and keep moving most days. A home monitor makes the first part easy, because single readings in a doctor’s office are often misleading.
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If you are starting from a low base, you do not need a 50-minute session on day one. The rrAD program itself started at 3 sessions of about 30 minutes and built up over months. Walking is the easiest entry point; I covered how many daily steps the large cohort studies actually support in Do You Really Need 10,000 Steps a Day?, and for a time-efficient option there is the 4×4 HIIT approach after 65.
To keep aerobic sessions in the moderate to vigorous range the trial targeted, a heart rate reading helps more than guessing by feel, especially in the first months.
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How This Fits With the Broader Evidence
rrAD is not the first trial to find that intensive blood pressure lowering does not clearly protect against dementia in a short window. The best-known comparison is SPRINT MIND, published in JAMA in 2019. It randomized 9,361 adults with hypertension (mean age 67.9, 35.6% women) to a systolic target below 120 mm Hg or below 140 mm Hg. Over a median follow-up of 5.11 years, probable dementia occurred in 149 people in the intensive group and 176 in the standard group (7.2 vs. 8.6 cases per 1,000 person-years; hazard ratio 0.83, 95% CI 0.67 to 1.04), which was not statistically significant.
But SPRINT MIND did find something rrAD could not: intensive control significantly reduced mild cognitive impairment (14.6 vs. 18.3 cases per 1,000 person-years; hazard ratio 0.81, 95% CI 0.69 to 0.95) and the combined outcome of mild cognitive impairment or probable dementia (hazard ratio 0.85, 95% CI 0.74 to 0.97). The authors noted that early termination and fewer dementia cases than expected meant the trial may have been underpowered for dementia itself.
Put the two together and a pattern emerges. SPRINT MIND was about 18 times larger, followed people more than twice as long, and counted clinical diagnoses rather than small score changes. It found a modest benefit on mild cognitive impairment. rrAD, smaller and shorter, measuring test scores in people who were not declining, found nothing significant. That is consistent with a real but slow-acting benefit of blood pressure control that needs years and large numbers to show up, and it is consistent with rrAD being too small to detect it.
For exercise, the picture is similar. Observational studies link regular walking to lower dementia risk (see how walking 3x a week may protect your brain), but randomized trials with cognitive endpoints have repeatedly struggled to show large, fast effects. rrAD adds one more well-run trial to that list. It also fits a broader lesson I keep returning to on this site: interventions that look powerful in cohort data often shrink when tested head to head, as with the shingles vaccine and dementia evidence, where randomized data are only now arriving.
Funding and conflicts. rrAD was led by UT Southwestern Medical Center. The authors’ disclosures list grants from the US National Institutes of Health, the National Institute on Aging and the Josephine Hughes Sterling Foundation during the study. Some co-authors reported personal fees or contracted research from pharmaceutical companies (including AstraZeneca and Eli Lilly) outside the submitted work; no industry funding of the trial itself was listed. For SPRINT MIND, several authors likewise reported industry fees or grants unrelated to the study.
FAQ
Does this trial mean exercise does not help prevent dementia?
No. It means that two years of supervised aerobic exercise did not produce a statistically significant extra improvement in cognitive test scores compared with a stretching control in older adults without dementia. Effects on long-term dementia risk were not measured.
Should I stop worrying about my blood pressure?
No. Blood pressure control prevents strokes and heart failure, and the larger SPRINT MIND trial linked intensive control to fewer cases of mild cognitive impairment. Any change to blood pressure or statin treatment should be made with your doctor.
How much exercise did the rrAD participants do?
They started with about 30 minutes 3 times a week and built up over 4 to 5 months to 40 to 50 minutes 4 to 5 times a week of supervised moderate to vigorous aerobic training, then kept that up for the rest of the two years.
Why did everyone’s scores go up?
Repeated testing produces practice effects, and all participants, including the usual care group, received structured contact, stretching and standard medical care. The trial was designed to detect differences between groups, and those differences were small and not significant.
Conclusion
The rrAD trial is an honest, well-designed test of a popular idea, and it came back null. Two years of serious aerobic training, aggressive blood pressure lowering and high-dose atorvastatin did not make 513 older adults measurably sharper than a group doing stretching and getting usual care. The right takeaway is not to abandon exercise or blood pressure control, which have strong reasons of their own and longer-term evidence behind them. It is to distrust anyone promising quick, measurable memory gains from a lifestyle program, and to treat brain protection as a decades-long project. For more on building activity into that long game, see resistance training and brain age.
If you want the full system behind the choices I make for my own health, including how I track blood pressure and training, I wrote it all down in The MVHK Protocol.
References
- Zhang R, Vidoni E, Vongpatanasin W, et al. Effects of Exercise and Intensive Vascular Risk Reduction on Cognitive Function in Older Adults: A Randomized Clinical Trial. JAMA Neurol. 2026;83(5):424-434. doi:10.1001/jamaneurol.2026.0359. PMID 41870419.
- ClinicalTrials.gov. Exercise and Intensive Vascular Risk Reduction in Preventing Dementia (rrAD). NCT02913664. Arms and interventions description.
- SPRINT MIND Investigators for the SPRINT Research Group; Williamson JD, Pajewski NM, et al. Effect of Intensive vs Standard Blood Pressure Control on Probable Dementia: A Randomized Clinical Trial. JAMA. 2019;321(6):553-561. PMID 30688979.
