What “90% of Strokes Are Preventable” Really Means

You may have seen the headline that 90% of strokes are preventable. It comes from INTERSTROKE, a large international study published in The Lancet in 2016 that compared 13,447 stroke patients with 13,472 matched people without stroke across 32 countries. Researchers found that 10 modifiable risk factors together accounted for 90.7% of the “population attributable risk” of stroke. That total held up across regions, age groups, and in both men and women.

Those 10 factors were high blood pressure, physical inactivity, unhealthy blood lipids, poor diet, abdominal obesity, psychosocial stress, smoking, heart conditions such as atrial fibrillation, alcohol, and diabetes.

A newer analysis, the Global Burden of Disease 2021 stroke study published in The Lancet Neurology in 2024, reached a similar conclusion. It found that 84% of the world’s stroke burden was attributable to 23 modifiable risk factors, led by high blood pressure, air pollution, smoking, and high LDL cholesterol.

Here is the plain-language nuance. These figures describe populations, not promises. They mean that if these risk factors could be removed across an entire community, most strokes would not happen. They do not mean anyone can push personal risk to zero, because age, genetics, and chance still play a part.

The honest message is this: up to 9 out of 10 strokes are linked to things we can change, and every improvement tilts the odds in your favor. Those changeable factors fall into two groups: the daily habits you control and the medical conditions you and your doctor manage together.

Branch 1: Lifestyle Modifiers

Follow a Mediterranean Eating Pattern

The strongest diet evidence comes from PREDIMED, a randomized trial of 7,447 Spanish adults at high cardiovascular risk, republished in the New England Journal of Medicine in 2018. People assigned to a Mediterranean diet supplemented with extra-virgin olive oil or mixed nuts had a 42% lower rate of stroke than those told to follow a reduced-fat diet. The 2024 American Heart Association and American Stroke Association (AHA/ASA) primary prevention guideline now recommends a Mediterranean pattern for adults.

This eating pattern centers on vegetables, legumes, whole grains, fish, olive oil, and nuts, with few refined carbohydrates or sugary drinks. Metabolically, it also steadies blood sugar and calms the chronic inflammation that quietly damages blood vessels.

Watch the salt and boost the potassium. In the Salt Substitute and Stroke Study of nearly 21,000 adults (NEJM, 2021), replacing regular salt with a potassium-enriched salt substitute lowered stroke risk by 14%. Please check with your doctor first if you have kidney disease or take medicines that raise potassium.

Aim for 150 Minutes of Activity Per Week

National guidelines call for at least 150 minutes of moderate activity, such as brisk walking, or 75 minutes of vigorous activity each week. In INTERSTROKE, physical inactivity was the second-largest contributor to stroke risk after high blood pressure.

The good news is that every bit counts. A 2024 meta-analysis of 15 studies following more than 750,000 adults for about 10 years found that moderate leisure-time activity cut stroke risk by 27-29% compared with no activity. Even activity below the recommended target still lowered risk by 18%. If 150 minutes feels out of reach, start with a 10-minute walk after meals and build from there.

Stop Smoking and Vaping

Current smoking raised the odds of stroke by about 67% in INTERSTROKE. Vaping is not a safe harbor. In a study of 161,529 American adults aged 18-44, people who both smoked and vaped had nearly three times the odds of stroke of people who used neither, and higher odds than people who only smoked cigarettes.

Long-term data on vaping alone are still limited, so the safest course is to quit both. Ask your doctor about counseling and cessation medications, which the 2024 guideline recommends.

Limit Alcohol (Less Is Better)

The old idea that a daily drink protects the brain has not held up when it comes to stroke. A 2023 INTERSTROKE analysis in Neurology found that heavier drinking was linked to higher stroke risk, especially bleeding strokes, while light drinking offered no protective benefit. Genetic data from more than 500,000 adults in the China Kadoorie Biobank showed stroke risk rising steadily as alcohol intake went up.

If you drink, keep it light and infrequent, and avoid binge drinking altogether.

Take Movement Breaks

Sitting for long stretches carries its own risk, separate from how much you exercise. A Canadian study of about 143,000 adults (Stroke, 2021) found that people under 60 with low activity who spent 8 or more hours a day sitting in their leisure time had roughly four times the stroke risk of those who sat less than 4 hours.

The 2024 AHA/ASA guideline added a new recommendation to screen for and counsel against sedentary behavior. A simple habit helps: stand, stretch, or walk for a few minutes every 30-60 minutes.

Other Factors That Matter

Your waistline is a window into your metabolism. The 2024 guideline notes that each 10-centimeter (about 4-inch) increase in waist size raises relative stroke risk by about 10%, and belly fat is a visible sign of insulin resistance.

Obstructive sleep apnea is an independent stroke risk factor as well. If you snore loudly or wake up unrefreshed, ask about testing, since treatment may help lower your risk.

Finally, stress counts. Psychosocial stress accounted for about 17% of stroke risk in INTERSTROKE. Restful sleep, close relationships, and time set apart for peace and prayer all help protect your brain.

Branch 2: Clinical Management

High Blood Pressure: The Number One Target

High blood pressure is the single largest changeable cause of stroke. It accounted for nearly half of stroke risk in INTERSTROKE and 57% of the global stroke burden in the 2021 Global Burden of Disease analysis.

The 2025 AHA/ACC high blood pressure guideline sets a goal below 130/80 mm Hg for most adults. A large 2016 meta-analysis in The Lancet, covering more than 600,000 participants, found that every 10-point drop in systolic pressure (the top number) lowered stroke risk by about 27%. The 2024 stroke guideline adds that most people who need medication do best on two or more blood pressure drugs.

Here is your action step: check your blood pressure at home with a validated upper-arm cuff, seated and rested, and bring your log to every appointment.

High Cholesterol: Know Your LDL

High LDL cholesterol ranks among the top five global stroke risk factors. In the SPARCL trial (NEJM, 2006), 4,731 people with a recent stroke or mini-stroke who took high-dose atorvastatin had a 16% lower risk of another stroke.

The later Treat Stroke to Target trial (NEJM, 2020) showed that aiming for an LDL below 70 mg/dL after a stroke cut major cardiovascular events compared with a looser target. The 2024 guideline recommends statins for adults who qualify based on overall cardiovascular risk, so ask your doctor what your personal LDL goal should be.

Diabetes, Prediabetes, and Insulin Resistance

Diabetes is a well-established stroke risk factor, but risk starts climbing earlier than many people realize. A 2012 meta-analysis in the BMJ linked prediabetes to a modestly higher future risk of stroke. In people who have already had a stroke, a 2024 review in Cardiovascular Diabetology found insulin resistance tied to a 56% higher risk of having another one.

The 2024 guideline strongly recommends GLP-1 medications for people with type 2 diabetes who also carry high cardiovascular risk. In my practice, I look beyond fasting glucose to HbA1c, fasting insulin, triglycerides, and waist size, because catching insulin resistance early is one of the most powerful prevention tools we have.

Atrial Fibrillation: The Hidden Risk Multiplier

Atrial fibrillation (AFib) is an irregular heartbeat that allows clots to form inside the heart. According to the CDC, AFib raises stroke risk about fivefold and causes about 1 in 7 strokes, and those strokes tend to be more severe.

The good news is that treatment works. In a 2007 meta-analysis of six trials with 2,900 participants, the blood thinner warfarin reduced stroke by 64% compared with placebo or no treatment, and newer blood thinners are at least as effective. Doctors use a simple scoring tool called CHA2DS2-VASc, which counts factors such as age, high blood pressure, diabetes, and prior stroke, to decide who benefits most.

Here is your action step: check your pulse for irregular beats, and take smartwatch alerts seriously. In the Apple Heart Study of 419,297 people, only about half of 1% received an irregular-pulse alert, but 84% of those alerts matched AFib on a simultaneous heart monitor. A watch alert is not a diagnosis, but it is a good reason to see your doctor.

Know the Warning Signs: BE FAST

Prevention also means acting quickly if a stroke happens, because clot-dissolving treatment works best within the first few hours. The American Stroke Association teaches the letters BE FAST so you can recognize the signs.

B stands for balance, a sudden loss of balance or coordination. E stands for eyes, a sudden loss or change in vision. F stands for face, one side of the face drooping. A stands for arm, weakness or numbness on one side of the body. S stands for speech, slurred or strange speech. T stands for time, meaning call 911 right away, even if the symptoms fade.

Don’t drive yourself to the hospital, and note when the symptoms began. That one detail helps the emergency team decide which treatments are still possible.

Your Stroke Prevention Action Steps

Start by knowing your numbers: blood pressure, LDL cholesterol, HbA1c, fasting insulin, and waist size. Check your blood pressure at home and aim for below 130/80 unless your doctor advises a different goal.

Build your meals around vegetables, legumes, fish, olive oil, and nuts, and use a potassium-enriched salt substitute if your doctor agrees. Move for at least 150 minutes each week, and stand up every 30-60 minutes during long stretches of sitting.

Quit smoking and vaping, and ask for help doing it. Keep alcohol to a minimum and never binge. Check your pulse now and then, and follow up on any smartwatch AFib alert.

Ask about sleep apnea if you snore or wake up tired. Take prescribed medications consistently, even when you feel fine. Finally, memorize BE FAST and share it with the people you love.

Conclusion

Stroke is common, but it is not inevitable. The research is remarkably consistent: most stroke risk traces back to blood pressure, cholesterol, blood sugar, heart rhythm, and everyday habits that we can change.

You do not have to fix everything at once. Pick one step this week, learn your numbers, and partner with your physician. Small, faithful changes add up, and caring well for the body you have been given is an investment in many more good years with the people you love.

References

1. Amarenco P, Bogousslavsky J, Callahan A 3rd, et al. High-dose atorvastatin after stroke or transient ischemic attack. N Engl J Med. 2006;355(6):549-559.
2. Amarenco P, Kim JS, Labreuche J, et al. A comparison of two LDL cholesterol targets after ischemic stroke. N Engl J Med. 2020;382(1):9-19.
3. American Stroke Association. B.E. F.A.S.T. materials.
4. Bushnell C, Kernan WN, Sharrief AZ, et al. 2024 Guideline for the primary prevention of stroke: a guideline from the American Heart Association/American Stroke Association. Stroke. 2024;55(12):e344-e424.
5. Centers for Disease Control and Prevention. About atrial fibrillation.
6. Centers for Disease Control and Prevention. Stroke facts.
7. De Santis F, Romoli M, Foschi M, et al. Risk of stroke with different levels of leisure-time physical activity: a systematic review and meta-analysis of prospective cohort studies. J Neurol Neurosurg Psychiatry. 2024;95(6):504-514.
8. Estruch R, Ros E, Salas-Salvadó J, et al. Primary prevention of cardiovascular disease with a Mediterranean diet supplemented with extra-virgin olive oil or nuts. N Engl J Med. 2018;378(25):e34.
9. Ettehad D, Emdin CA, Kiran A, et al. Blood pressure lowering for prevention of cardiovascular disease and death: a systematic review and meta-analysis. Lancet. 2016;387(10022):957-967.
10. GBD 2021 Stroke Risk Factor Collaborators. Global, regional, and national burden of stroke and its risk factors, 1990-2021: a systematic analysis for the Global Burden of Disease Study 2021. Lancet Neurol. 2024;23(10):973-1003.
11. Hart RG, Pearce LA, Aguilar MI. Meta-analysis: antithrombotic therapy to prevent stroke in patients who have nonvalvular atrial fibrillation. Ann Intern Med. 2007;146(12):857-867.
12. Institute for Health Metrics and Evaluation. The Lancet Neurology: air pollution, high temperatures, and metabolic risk factors driving global increases in stroke, with latest figures estimating 12 million cases and over 7 million deaths from stroke each year. Published September 18, 2024.
13. Jones DW, Ferdinand KC, Taler SJ, et al. 2025 AHA/ACC/AANP/AAPA/ABC/ACCP/ACPM/AGS/AMA/ASPC/NMA/PCNA/SGIM guideline for the prevention, detection, evaluation and management of high blood pressure in adults: a report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. Hypertension. 2025;82(10):e212-e316.
14. Joundi RA, Patten SB, Williams JVA, Smith EE. Association between excess leisure sedentary time and risk of stroke in young individuals. Stroke. 2021;52(11):3562-3568.
15. Kaynak N, Kennel V, Rackoll T, Schulze D, Endres M, Nave AH. Impaired glucose metabolism and the risk of vascular events and mortality after ischemic stroke: a systematic review and meta-analysis. Cardiovasc Diabetol. 2024;23(1):323.
16. Lee M, Saver JL, Hong KS, Song S, Chang KH, Ovbiagele B. Effect of pre-diabetes on future risk of stroke: meta-analysis. BMJ. 2012;344:e3564.
17. Millwood IY, Walters RG, Mei XW, et al. Conventional and genetic evidence on alcohol and vascular disease aetiology: a prospective study of 500 000 men and women in China. Lancet. 2019;393(10183):1831-1842.
18. Neal B, Wu Y, Feng X, et al. Effect of salt substitution on cardiovascular events and death. N Engl J Med. 2021;385(12):1067-1077.
19. O’Donnell MJ, Chin SL, Rangarajan S, et al. Global and regional effects of potentially modifiable risk factors associated with acute stroke in 32 countries (INTERSTROKE): a case-control study. Lancet. 2016;388(10046):761-775.
20. Parekh T, Pemmasani S, Desai R. Risk of stroke with e-cigarette and combustible cigarette use in young adults. Am J Prev Med. 2020;58(3):446-452.
21. Perez MV, Mahaffey KW, Hedlin H, et al. Large-scale assessment of a smartwatch to identify atrial fibrillation. N Engl J Med. 2019;381(20):1909-1917.
22. Smyth A, O’Donnell M, Rangarajan S, et al. Alcohol intake as a risk factor for acute stroke: the INTERSTROKE study. Neurology. 2023;100(2):e142-e153.