Smoking is linked to a higher risk of dementia, and overall dementia is more common in people who smoke than in people who never smoked, especially among current smokers.
What dementia is and why risk matters
Dementia is a general term for conditions that slowly damage the brain and affect memory, thinking, and daily activities. The most common types are Alzheimer’s disease and vascular dementia. Since there is no cure yet, understanding risk factors like smoking is very important.
Evidence that smokers have a higher risk of dementia
Large research studies have followed thousands of adults for many years to see who develops dementia. A recent analysis of long term data found that people who were **current smokers** had about a **31 percent higher risk of dementia** compared with people who did not smoke.[1] This means that, in groups of similar age and health, dementia shows up more often among smokers.
In that same research, women who smoked and were under 85 at follow up had an even higher increase in risk, about 54 percent.[1] Results like these suggest that smoking does not just harm the heart and lungs. It also appears to speed up brain problems that can lead to dementia.
An accessible overview of this link is given in an article on smoking and dementia risk, which explains how smoking affects the brain’s blood vessels and cells and stresses that many smokers underestimate this brain risk.[2] You can read it here: https://doralhw.org/smoking-and-dementia-the-brain-risk-most-smokers-seriously-underestimate/.[2]
How smoking may raise dementia risk
Researchers point to several ways smoking may make dementia more common among smokers:
1. Damage to blood vessels
Cigarette smoke harms blood vessels throughout the body, including those that feed the brain. Over time this can cause:
– Narrowed or blocked arteries
– Small strokes or “silent” brain injuries
– Reduced blood flow and oxygen delivery to brain tissue
These changes are closely linked to vascular dementia and also make Alzheimer’s disease more likely or more severe.[2]
2. Inflammation and oxidative stress
Chemicals in tobacco smoke increase inflammation and “oxidative stress,” which is a type of damage to cells and DNA caused by unstable molecules called free radicals.[2] When this happens in the brain, it can injure neurons and support cells, weaken connections between brain cells, and speed up the buildup of abnormal proteins associated with dementia.
3. Effects on heart and metabolic health
Smoking is a major risk factor for:
– High blood pressure
– High LDL cholesterol and low HDL cholesterol
– Stroke and heart disease
– Type 2 diabetes
All of these are known risk factors for dementia later in life.[4][5] When they are present together, they greatly increase the chance that a smoker will develop dementia in older age.
4. Early life and midlife brain effects
Some research has followed people from young adulthood into midlife. In one study, smoking in young adulthood predicted poorer thinking and memory performance by midlife, even after accounting for other health factors.[3] This suggests that smoking may start harming brain health long before dementia is diagnosed. You can view that study summary at PubMed: https://pubmed.ncbi.nlm.nih.gov/41493877/.[3]
Is every smoker certain to get dementia?
No. Not every person who smokes will develop dementia, and some people who never smoke still get dementia. Age, genes, education level, other illnesses, and environment all play roles.[4][5] However, smoking is considered a **modifiable** risk factor, which means it is something a person can change to lower their odds.
Experts describe dementia as the result of many hits over a lifetime: injuries, unhealthy habits, medical conditions, and sometimes inherited risk. Smoking is one of those hits. The more a person smokes and the longer they smoke, the higher the total damage tends to be.
What happens if someone quits smoking?
Many studies that compare current smokers, former smokers, and never smokers find that current smokers usually have the highest risk. Former smokers tend to fall somewhere in between or closer to never smokers, depending on how long ago they quit and how heavily they once smoked. This pattern suggests that stopping smoking can lower risk over time.
While the exact numbers differ across studies, dementia researchers and public health groups often list quitting smoking among the key steps that may help protect brain health, along with:
– Staying physically active
– Managing blood pressure, cholesterol, and diabetes
– Avoiding excessive drinking
– Staying socially and mentally active
These steps work together to support both heart and brain health.[4][5]
Smoking as part of a bigger risk picture
Dementia risk is shaped by many factors across the entire life span. A recent overview in The Lancet: Healthy Longevity, explained in popular form by ScienceAlert, described lifestyle risks like smoking, heavy drinking, inactivity, and social isolation alongside other influences such as pollution, head injuries, obesity, and depression.[5] That article, which you can read here https://www.sciencealert.com/the-roots-of-dementia-trace-back-all-the-way-to-childhood-experts-find, argues that protecting brain health should be viewed as a lifelong goal, starting in childhood and young adulthood.[5]
Other resources on dementia risk also mention smoking among the key risk factors, along with age, diabetes, high blood pressure, lower levels of education, depression, loneliness, poor sleep, and food insecurity.[4] For a clear summary of several of these risks, see: https://www.elderlawanswers.com/new-research-on-dementia-risk-factors-screenings-21360.[4]
What this means for smokers and families
For someone who smokes, the research does not guarantee dementia, but it does show that dementia is more common in smokers and that smoking adds to other brain and heart risks over time.[1][2][5] Quitting smoking, even later in life, is likely to benefit overall health and may help lower the chance or delay the onset of dementia.
If a person already has memory changes, stopping smoking may still improve blood flow, lung function, and quality of life, which can make it easier to stay active and engaged. For families, understanding that smoking affects the brain as well as the heart can make conversations about quitting feel more urgent and meaningful.
If you or someone you know is concerned about dementia risk and smoking, it can help to speak with a health care professional about:
– Safe
