This Lifestyle Factor Predicts Brain Aging Better Than Genetics, According to Neurologists

The statistics surrounding dementia and Alzheimer’s are alarming. According to the Alzheimer’s Association, more than 7 million Americans are living with Alzheimer’s, a disease that is a form of dementia, which is an umbrella term for a range of symptoms involving cognitive decline.

Since dementia and Alzheimer’s touch so many lives, you can likely think of at least one person who has it. If someone in your family was diagnosed with Alzheimer’s, you may wonder if this means that a diagnosis is in your future too. 

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According to Dr. Majid Fotuhi, MD, PhD, a neurologist and the author of The Invincible Brain, having a family history of dementia or Alzheimer’s doesn’t mean you will get it too. He says it’s even more unlikely if your family member developed dementia later in life. “Late-life cognitive decline has a very small genetic component.”

Dr. Fotuhi says that the same is true for dementia in general. “There is an important difference between early-onset Alzheimer’s disease, which is rare and driven by specific gene mutations, and late-onset Alzheimer’s disease, which represents more than 95% of cases and is strongly shaped by lifestyle, vascular health and daily habits,” he explains.

In fact, all four neurologists we spoke with say that diet and lifestyle predict how one’s brain will age more strongly than genetics, especially when it comes to one specific habit.

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How Much Does Diet and Lifestyle Impact Brain Health as We Age?

Neurologist Dr. Doug Strobel, MD, says that diet and lifestyle almost entirely control brain health related to aging, not genetics. While genetics isn’t a primary driver of dementia, Dr. Strobel says that the mere act of getting older is a risk factor. This is because cumulative biological changes can make the brain more vulnerable to damage. It’s similar to why age is a risk factor for heart disease; the body becomes less resilient over time. The same is true for the brain. For this reason, the probability of developing dementia doubles roughly every five years.

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You can’t control getting older, but you can control your diet and lifestyle habits, something all four neurologists we talked to say is crucial for supporting an aging brain. “Diet and lifestyle play equally important roles in healthy brain aging,” says neurologist Dr. Jon Stewart Hao Dy, MD. 

Dr. Dy explains that this includes eating a variety of nutrient-rich foods, exercising regularly, getting enough sleep and regularly participating in stimulating activities, such as playing music, dancing or going to cultural events. “If these diet and lifestyle habits are combined, cognitive health and function can be preserved, at the very least, as one ages,” Dr. Dy says.

Dr. Fotuhi also says that healthy diet and lifestyle habits can control how healthy their brain will age almost entirely. “Your choices about diet, exercise, stress management, sleep and how much you challenge your brain daily have a profound impact on how well you preserve and grow your brain capacity with aging,” he notes.

He believes in five pillars of brain health: exercise, sleep, brain-healthy nutrition, positive mindset and brain training (targeted games, exercises and activities aimed at supporting cognitive health). “All five pillars matter and they work together to maintain and boost our cognitive capacity with aging,” Dr. Fotuhi says.

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While having brain-healthy habits in place can go a long way in protecting cognitive health as we age, Dr. Charalampos Tzoulis, MD, PhD, a neurology professor at the University of Bergen, says that we can’t control how our brain will age completely.

“We can influence risk, but we cannot fully control it. If we had complete control, we would already have solved much of the growing global burden of brain aging and neurodegenerative disease. But we do know that the same factors linked to good general health are also associated with healthier brain aging and a lower risk of dementia,” Dr. Tzoulis says. 

The Habit That Matters Most When It Comes to the Aging Brain, According to Neurologists

While all of the aforementioned habits are important for supporting brain health as we age, Dr. Hy and Dr. Strobel believe that following a brain-healthy diet is most important. Three eating plans scientifically linked to reducing the risk of dementia are the Mediterranean diet, the DASH diet and the MIND diet. In fact, the MIND diet was created specifically for lowering the risk of dementia. 

All three of these eating plans emphasize eating a wide range of fruits, vegetables, plant-based proteins, whole grains and foods high in omega-3 fatty acids such as seafood, nuts and olive oil. “You need a whole food, plant-based diet if you want to overcome your memory loss or your potential for memory loss,” Dr. Strobel says. 

Dr. Hy agrees, saying that this is especially the case for a stroke-related type of dementia called vascular dementia, which is the second most common form of dementia in the U.S. “Vascular risk factor prevention and control through proper diet and nutrition is probably the single most important factor in preventing accelerated brain atrophy, brain aging and dementia,” he explains.

One of the reasons why primarily plant-based eating plans are scientifically linked to reducing the risk of dementia is that foods like fruit, vegetables, legumes, nuts, seeds, spices and herbs are all high in antioxidants. Antioxidants help reduce inflammation in the brain and protect it from neurodegenerative diseases. 

This Lifestyle Factor Should Be Prioritized Too

While Dr. Sy and Dr. Strobel believe that diet is most important when it comes to brain health, Dr. Fotuhi believes that exercise plays a more prominent role. “Exercise is the cornerstone of brain vitality. It is the most powerful and consistently supported strategy we have for protecting cognitive function as we age.  When it comes to brain health, I believe exercise is the fountain of youth,” he says.

Dr. Fotuhi explains that exercise impacts the brain on a cellular level by increasing the number and efficiency of mitochondria, the energy factories inside neurons. “It stimulates the birth of new neurons in the hippocampus, the thumb-size brain structure for learning and memory that can shrink with aging,” he says. 

Scientific research shows that exercise can literally make the hippocampus bigger. In one study, aerobic activity was shown to increase the hippocampus. Considering the fact that the brain naturally shrinks with age, this is pretty incredible. 

“Even moderate activity makes a difference. Research shows that people who walk about 5,000 steps a day or more tend to have lower levels of amyloid, the toxic protein that accumulates and contributes to brain atrophy in patients with Alzheimer’s disease,” Dr. Fotuhi says. 

Mitigating the risk of dementia doesn’t just come down to one factor. The truth is, every part of how you live impacts the brain, not just one habit. “Rather than looking for a single ‘magic bullet,’ the strongest message is that brain health is built over time through multiple habits and relationships,” Dr. Tzoulis says.

With this in mind, the more brain-healthy habits you have in place, the better. Start with following a brain-healthy diet, but don’t stop there. Your cognitive health depends on it.

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Sources:

• Alzheimer’s Disease Facts and Figures. Alzheimer’s Association
• Dementia vs. Alzheimer’s Disease: What Is the Difference? Alzheimer’s Association
• Dr. Majid Fotuhi, MD, PhD, neurologist and the author of The Invincible Brain
• Dr. Doug Strobel, MD, neurologist and founder of Healthy Brain Doc
• What Causes Alzheimer’s Disease? National Institute on Aging
• Dr. Jon Stewart Hao Dy, MD, neurologist specializing in neuroimmunology, neuromuscular diseases and neuroarts
• Dr. Charalampos Tzoulis, MD, PhD, neurology professor at the University of Bergen
• Fekete, M., Varga, P., Ungvari, Z., et al. (2025). The role of the Mediterranean diet in reducing the risk of cognitive impairment, dementia, and Alzheimer’s disease: a meta-analysis. Geroscience. 47(3):3111-3130 
• Mehdi Abbasi, M., Khandae, S., Shahabi, M., et al. (2025). Association between the DASH diet and Alzheimer’s disease in a case-control study.Scientific Reports. 15:23312. doi: 10.1038/s41598-025-05416-z 
• Morris, M. C., Tangney, C. C., Wang, Y. (2015). MIND Diet Associated with Reduced Incidence of Alzheimer’s Disease.Alzheimer’s & Dementia. 11(9):1007-1014
• Top Things to Know: Vascular Contributions to Cognitive Impairment and Dementia in the United States: Prevalence and Incidence. American Heart Association
• Hee Lee, K., Cha, M., and Hwan Lee, B. (2020). Neuroprotective Effect of Antioxidants in the Brain. International Journal of Molecular Sciences. 21(19):7152 
• Erickson, K. I., Voss, M. W., Shaurya Prakash, R., et al. (2011). Exercise training increases size of hippocampus and improves memory.Proceedings of the National Academy of Sciences. 108(7):3017-22
• Wendy Y., W. Y., Kirn, D. R., Rabin, J. S., et al. (2025). Physical activity as a modifiable risk factor in preclinical Alzheimer’s disease. Nature Medicine. 31, 4075-4083