More than seven million Americans are living with Alzheimer’s disease today, according to a 2025 Alzheimer’s Association report. That number can feel frightening. But here is something worth holding onto: getting dementia is not inevitable, even if you live to a very old age.
In fact, neurologists say that 40 to 45 percent of dementia risk comes from lifestyle and health factors you can actually change. That figure comes from both the 2024 Lancet Commission and 2026 World Health Organization guidelines on dementia risk reduction.
Dr. Kaitlin Seibert, MD, a behavioral neurologist with Cleveland Clinic’s Center for Brain Health, puts it plainly. A person’s dementia risk comes from a mix of genetics, environment, and lifestyle. “We cannot control all of it, but lifestyle habits do matter,” she says.
It Is Never Too Late to Start
If you have not thought much about brain health until now, do not worry. Both Dr. Seibert and Dr. Hurmina Muqtadar, MD, a neurologist with Endeavor Health Neurosciences, say it is never too late to make a difference.
Dr. Muqtadar points to scientific evidence showing that diet and lifestyle changes made after age 60 to 65 can still help. The earlier and longer those habits are in place, the greater the benefit, but starting now still counts.
Two major studies back this up. The U.S. POINTER study followed more than 2,000 adults between ages 60 and 79. After two years of diet and lifestyle changes, participants showed improved cognition. A 2024 study published in Nature Medicine followed more than 6,000 adults between ages 55 and 77. After three years, those who made healthy changes scored significantly better on cognitive tests than those who did not.
The Habit Neurologists Most Want You to Drop
If you can only make one change, Dr. Muqtadar says to start with your diet. Specifically, cut back on ultra-processed foods. “The strongest dietary predictor of dementia is high consumption of ultra-processed foods,” she says.
A 2026 study published in the American Journal of Public Health found that high intake of ultra-processed foods is associated with a higher risk of cognitive impairment. Dr. Muqtadar explains why: these foods disrupt the gut microbiome, which affects the brain through the brain-gut connection. They can also promote inflammation, insulin resistance, and vascular dysfunction.
5 Habits to Avoid for a Healthier Brain
Beyond diet, both neurologists point to five specific habits that raise dementia risk. Here is what they say to watch out for.
1. Smoking or Vaping
Most of us already know smoking is hard on the heart. But it is hard on the brain, too. A 2025 study published in BMC Public Health found that smoking can increase the risk of dementia by between 31 and 54 percent.
Dr. Seibert explains that smoking damages blood vessels throughout the body, including the small ones in the brain. Over time, that damage can increase the risk of stroke and other changes that affect memory and thinking.
2. Sitting Too Much
A sedentary lifestyle raises Alzheimer’s risk, both neurologists agree. Dr. Muqtadar explains that movement keeps blood flowing to the brain, which means a steady supply of oxygen and nutrients. Dr. Seibert adds that regular physical activity also helps control blood pressure, cholesterol, blood sugar, and weight, all of which affect brain health.
3. Skimping on Sleep
Dr. Seibert describes sleep as “the brain’s overnight cleaning system.” During sleep, the brain clears away waste products, including proteins linked to Alzheimer’s disease. Poor sleep also affects attention, memory, and cardiovascular health.
She recommends that most adults aim for seven to nine hours of good-quality sleep each night. Conditions like sleep apnea, she says, should be treated when present.
4. Drinking Too Much Alcohol
Heavy alcohol use can lead to brain cell damage and tissue shrinkage, according to research. Dr. Seibert says the biggest concern is excessive use, which over time can cause cognitive impairment severe enough to interfere with daily life. “When it comes to brain health, moderation matters,” she says.
5. Skipping Vision and Hearing Checkups
This one surprises many people. But Dr. Seibert makes the connection clear. “Information has to get into the brain before we can remember it later,” she says. That is why keeping vision and hearing checked and treated as we age matters so much for brain health.
Research shows that hearing loss is linked to doubling the risk of dementia and is considered a major, potentially modifiable risk factor. Vision impairment is also associated with dementia, according to the National Institute on Aging.
Brain Health Is Built Over Time
Neither doctor suggests that one habit alone will protect your brain. “Brain health is really the result of many habits over time,” Dr. Seibert says. But if you are not sure where to begin, this list is a solid place to start.
Small changes, made now, can still make a real difference.
