Think dementia is only something to worry about when you’re older? Think again. While uncontrollable factors like age, genetics, and family history all play a role in the development of the neurodegenerative condition, new research shows there are some health factors you can control that reduce the likelihood of the illness—especially in your 40s.
Experts in This Article
a neurosurgeon at Northwell Staten Island University Hospital
It's true: What you do in midlife can have major effects on your brain health as you age. To understand why, we tapped a neurosurgeon, who also shared ten simple, science-backed ways to reduce your dementia risk and protect your brain, starting...now.
Why your 40s matter for brain health
The groundwork for your future cognitive function is laid decades before old age, and your 40s are a turning point. This is when risk factors like high blood pressure, diabetes, and poor lifestyle habits often begin to set in, says Jonathan Rasouli, MD, a neurosurgeon at Northwell Staten Island University Hospital. Plus, your brain’s ability to repair itself naturally declines with age, Dr. Rasouli adds. That’s why taking action now can go a long way in preserving memory, mental sharpness, and reducing the risk of dementia later on.
10 things to do in your 40s to lower your dementia risk
“Small, consistent lifestyle changes can drastically reduce your dementia risk and improve overall quality of life,” Dr. Rasouli says. Here are everyday, science-backed habits that can boost brain health and help lower your risk of cognitive decline and dementia. While many of these changes are often implemented in your 50s, getting a head start in your 40s is even better—for your brain and whole body.
1. Keep your blood pressure in check
High blood pressure isn’t just a heart concern—it’s a brain threat, too. It can damage blood vessels in the brain, reduce blood flow, and increase the risk of stroke and cognitive decline, Dr. Rasouli says.1 A landmark study by SPRINT MIND found that lowering systolic blood pressure (i.e., the top number) below 120 mmHg significantly reduced the risk of mild cognitive impairment (MCI), which often precedes dementia.
All this to say, if you have untreated high blood pressure, talk to your healthcare provider about ways to manage your levels. This may include taking medications, limiting sodium and alcohol intake, and increasing potassium intake (along with nutritious fruits and veggies, lean protein, and healthy fats).
2. Manage your cholesterol levels
What’s good for your arteries is also good for your brain. This is why alongside lowering blood pressure, keeping cholesterol in check is important for brain health, too. Research has shown that midlife high cholesterol midlife is linked to cognitive impairment later in life.2 More specifically, it can lead to plaque buildup (a sticky, fatty substance) in your arteries, which can restrict blood flow to the brain and increase your risk of stroke and dementia, Dr. Rasouli says.
Managing your cholesterol will look similar to lowering blood pressure, and involves eating a balanced diet (the DASH or Mediterranean diets are often recommended for heart and brain health), getting regular physical activity, and taking medication, if needed.
3. Treat your diabetes ASAP
Uncontrolled diabetes affects more than your blood sugar—it can affect your brain, too. High blood sugar damages blood vessels and nerves, including those in the brain, potentially raising your Alzheimer’s risk, Dr. Rasouli says. The Alzheimer’s Drug Discovery Foundation also notes that midlife onset of type 2 diabetes significantly increases dementia risk. But the good news is that diabetes can be managed through lifestyle changes and proper medical care.
For example, monitoring your blood sugar, taking any prescribed medications (such as GLP-1s or insulin), getting regular exercise, and eating balanced meals that include lean protein, healthy fats, and complex carbohydrates, can all help stabilize blood sugar. Be sure to always follow your healthcare provider's diabetes treatment plan to avoid any long-term complications, too.
4. Prioritize your mental health
Turns out, your cognitive and emotional health go hand in hand. Dr. Rasouli says that chronic depression and anxiety are associated with shrinkage in areas of the brain that are key to memory, including the hippocampus (i.e., a small inner portion of the brain that helps with learning).3 Studies have also found that depression may more than double dementia risk.4
While the exact connection between dementia risk and depression is not fully understood, experts have found that treating underlying depression can help mitigate some of these risks of cognitive decline. Treatment includes a combination of methods including talk therapy, psychiatric medication, regular movement, sleep, and social interaction with loved ones, friends, and community. All can contribute to a healthier, and happier, brain.
Note: If you or someone you know is experiencing difficulties with their mental health, call SAMHSA’s National Helpline at 1-800-662-HELP (4357) or go to FindTreatment.gov for resources and treatment options. If you’re having thoughts of harming yourself or others, call or text 988 for the Suicide & Crisis Lifeline.
5. Quit smoking for good
Smoking, especially if you started smoking in midlife, is associated with a 79 percent higher risk of Alzheimer's disease. Dr. Rasouli says this is because smoking restricts the flow of oxygen to the brain, increases overall inflammation in the body, and accelerates cognitive decline.5,6,7 In other words, quitting as soon as possible can improve your blood circulation and oxygen flow, and slash your risk of dementia, he adds.
Need help kicking the habit? Reach out to your healthcare provider or call 1-800-QUIT-NOW for more resources.
6. Rethink your drinking habits
Moderation is key when it comes to alcohol and brain health. Heavy drinking “shrinks brain volume and damages neurons,” Dr. Rasouli says. On the flip side, studies have found that light to moderate drinking is associated with a lowered cognitive risk—but only if it stays within certain limits.8 For most people, that equates to less than one to two drinks per day maximum.
7. Maintain a healthy weight for your body size
Not everyone needs to lose weight to protect their brain. If you and your provider determine that you have overweight—and that some of your health markers (i.e., blood pressure, cholesterol, etc.) would improve if you lost weight—you may consider starting a weight-loss regimen that keeps proper nutrition, mental safety, and overall health in mind.
The reason some providers recommend weight loss? Obesity in midlife is associated with a roughly 30 percent higher risk of dementia. And sometimes, having overweight is associated with higher levels of inflammation, insulin resistance, and poor cardiovascular health, all of which can negatively affect the brain, Dr. Rasouli says.9
Ultimately, managing a healthy weight for your height and body size—through eating nutritious foods, getting regular exercise, logging quality sleep, and getting support from your provider—can help you brain long term. Just remember: Health looks different for everyone. If you’re concerned about weight or your relationship with food, the National Eating Disorders Association (NEDA) has resources to help.
8. Move your body more
Exercise isn’t just for physical fitness—it’s also great brain fuel. Dr. Rasouli says that regular movement increases blood flow to the brain, reduces inflammation, and supports memory and cognitive function through the release of a protein called brain-derived neurotrophic factor (BDNF), which helps grow and maintain nerve cells.
While committing to a workout routine in your 40s is amazing (go for it!), you don't have to go hard in the gym every day to reap the brain benefits of exercise. Even short walks, dancing in your kitchen, or taking the stairs add up, as long as you're reaching about 150 minutes of exercise per week.
9. Keep your vision and hearing sharp
Your sense of sight and sound can dull in your 40s and contribute to cognitive decline. For example, Dr. Rasouli says that even mild hearing loss can double your risk of dementia. That's because the inability to tune into your surroundings and nearby people can contribute to social isolation and depression, which are tied to cognitive decline. Vision loss can have the same effect, unfortunately.
To keep your brain in tip-top shape, it's important to get regular vision and hearing screenings from your healthcare provider, who can refer you to a specialist if needed. If hearing or vision loss is detected, you may be prescribed hearing aids or glasses, which can help keep your brain active and engaged, Dr. Rasouli adds.
10. Protect yourself from air pollution
You can't entirely avoid this one, but research shows that long-term exposure to air pollution is linked to increased brain inflammation and accelerated cognitive decline.10 So, if you live in a place with high levels of air pollution (aka smog), try using air purifiers indoors, wearing masks on high-smog days, and limiting exposure to traffic fumes (think: close your windows while sitting in gridlock), Dr. Rasouli says You can also check air quality apps and stay indoors when levels are high.
When to see a healthcare provider
It's easy to chalk up forgetfulness or mental fog to normal aging. And yes, some cognitive decline is a natural part of getting older. But if memory issues start to affect your daily life, it’s time to talk to a healthcare provider.
Keep in mind that memory loss isn’t the only sign of dementia. There are other red flags, too. Other early symptoms of Alzheimer’s and similar conditions can include:
- Trouble planning or solving problems
- Difficulty completing routine tasks
- Getting confused about time or place
- Struggling to understand visual or spatial cues
- Trouble finding the right words when speaking or writing
- Misplacing things and not being able to retrace your steps
- Poor judgment or decision-making
- Pulling away from work or social activities
- Noticeable mood or personality changes
Having one or two of these doesn’t automatically mean you or a loved one has dementia—but they are worth getting checked out. The sooner you get clarity, the sooner you can take steps to support brain health.
Final thoughts
“Brain health is a lifelong investment, and your 40s are a prime time to take action,” Dr. Rasouli says. “The key is prevention—once neurodegenerative changes start, they’re difficult to reverse. Prioritize your brain now, and it will thank you later.”
- Pacholko, A., & Iadecola, C. (2024). Hypertension, neurodegeneration, and cognitive decline. Hypertension, 81(5), 991–1007. https://doi.org/10.1161/hypertensionaha.123.21356
↩︎ - Wee, Jason et al. “The relationship between midlife dyslipidemia and lifetime incidence of dementia: A systematic review and meta-analysis of cohort studies.” Alzheimer's & dementia (Amsterdam, Netherlands) vol. 15,1 e12395. 8 Mar. 2023, doi:10.1002/dad2.12395 ↩︎
- Geraets, Anouk F J et al. “The relation of depression with structural brain abnormalities and cognitive functioning: the Maastricht study.” Psychological medicine, vol. 52,15 1-10. 26 Feb. 2021, doi:10.1017/S0033291721000222 ↩︎
- Elser H, Horváth-Puhó E, Gradus JL, et al. Association of Early-, Middle-, and Late-Life Depression With Incident Dementia in a Danish Cohort. JAMA Neurol. 2023;80(9):949–958. doi:10.1001/jamaneurol.2023.2309 ↩︎
- Toda, N., & Okamura, T. (2016). Cigarette smoking impairs nitric oxide-mediated cerebral blood flow increase: Implications for alzheimer’s disease. Journal of Pharmacological Sciences, 131(4), 223–232. https://doi.org/10.1016/j.jphs.2016.07.001
↩︎ - Elisia, I., Lam, V., Cho, B. et al. The effect of smoking on chronic inflammation, immune function and blood cell composition. Sci Rep 10, 19480 (2020). https://doi.org/10.1038/s41598-020-76556-7 ↩︎
- Benito-León, J., Ghosh, R., Lapeña-Motilva, J. et al. Association between cumulative smoking exposure and cognitive decline in non-demented older adults: NEDICES study. Sci Rep 13, 5754 (2023). https://doi.org/10.1038/s41598-023-32663-9 ↩︎
- Rehm, Jürgen et al. “Alcohol use and dementia: a systematic scoping review.” Alzheimer's research & therapy vol. 11,1 1. 5 Jan. 2019, doi:10.1186/s13195-018-0453-0 ↩︎
- Ellulu, Mohammed S et al. “Obesity and inflammation: the linking mechanism and the complications.” Archives of medical science : AMS vol. 13,4 (2017): 851-863. doi:10.5114/aoms.2016.58928 ↩︎
- Huang, L., Hu, X., Liu, J. et al. Air pollution is linked to cognitive decline independent of hypersensitive C-reactive protein: insights from middle-aged and older Chinese. Environ Health 23, 111 (2024). https://doi.org/10.1186/s12940-024-01148-1 ↩︎
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