It’s natural for people to worry about their health as they age. A decline in physical abilities is inevitable, but that inevitability makes it possible for people to anticipate and prepare for lifestyle changes that accompany the loss of muscle mass.
A decline of cognitive ability is less easy to predict. A degree of cognitive impairment is natural but not inevitable. Most people lose some ability to form new memories — “where did I put my keys?” — as they age, thanks largely to biomechanical processes that researchers are only beginning to understand. Yet SuperAgers remain cognitively sharp into their 80s and 90s.
Normal memory loss accompanying aging may prompt older adults to fear the onset of dementia. Fortunately, dementia is significantly less common (albeit more disabling) than typical age-related memory loss. About 11% of Americans age 65 or older have Alzheimer’s disease, the most common form of dementia. About a third of Americans who are 85 or older suffer from the disease. While those statistics are concerning, they reveal that most people will not suffer from a form of dementia as they grow older.
Dementia Risk Factors
Although researchers have studied dementia for decades, they have not identified a definitive cause of Alzheimer’s disease. Scientists know that dementia results from damage to nerve cells and their connections in the brain, but why some brains experience that damage while others do not is unclear. Genetic makeup seems to play a role in the development of dementia in some patients, but a combination of age-related changes in the body, environmental factors, and lifestyle choices may all determine whether an older adult acquires dementia.
Aging is a risk factor associated with the development of Alzheimer’s, but as people age, they can avoid other risk factors that might spell the difference between developing and avoiding the disease. To the extent that environmental and lifestyle choices determine whether an older adult develops Alzheimer’s, making healthy choices might act as a safeguard against the disease.
Reducing the Risk
Since the causes of Alzheimer’s disease are unclear, it is impossible to know whether preventive steps to avoid the disease will be effective. The best current medical information nevertheless suggests that there are steps an older adult can take to reduce the risk of developing dementia.
- Exercise your body.
Physical activity helps keep bodies and minds healthy. While most people understand that a lack of exercise impairs the body’s ability to function, evidence also demonstrates a relationship between physical inactivity and cognitive decline. Inactivity has long been seen as a risk factor for the development of Alzheimer’s disease.
A 2025 study by the Johns Hopkins Bloomberg School of Public Health “found that engaging in as little as 35 minutes of moderate to vigorous physical activity per week, compared to zero minutes per week, was associated with a 41% lower risk of developing dementia over an average four-year follow-up period.” Greater amounts of physical activity correlated with greater reductions of dementia risk, but even five minutes of exercise a day can reduce dementia risk in older adults.
- Exercise your brain.
Whether brain exercises (also known as brain training) can reduce the risk of dementia is unclear. Recent evidence nevertheless suggests that a specific type of brain training has the potential to delay the onset of Alzheimer’s disease.
A component of the nervous system known as the cholinergic system generates neurotransmitters to regulate memory, cognition, and other brain functions. The function of the cholinergic system declines with age. A 2025 study found that cognitive training can help counteract age-related decline in the cholinergic system and slow the deterioration of memory. The study reported that cognitive speed training (also known as “speed of processing” training) was particularly effective.
Cognitive speed training encourages people to locate visual information quickly on a computer screen. As the training continues, individuals are asked to perform increasingly complex tasks in a shorter time. The exercises offered by brainHQ are examples of cognitive speed training.
The results of the 2025 study appear to be confirmed by a study published in 2026. Study participants who were 65 or older completed five to six weeks of cognitive speed training, followed by additional sessions one to three years later. Twenty years later, those participants had significantly lower rates of dementia than participants who did not complete the training.
Some participants in both groups developed dementia, so brain exercises cannot be said to eliminate the risk of acquiring Alzheimer’s disease. Still, the study adds to a growing body of evidence that some kinds of cognitive training may at least delay the onset of dementia.
- Stop smoking.
A 2015 review of 17 studies found that smokers are 30% more likely than nonsmokers to develop some form of dementia and 40% more likely to develop Alzheimer’s disease. The number of cigarettes a smoker consumes each day is correlated with an increasing risk of developing dementia. On the other hand, a person who stops smoking at age 60 can significantly reduce the risk of dementia within 5 to 10 years.
- Curb alcohol consumption.
Significant evidence links the excessive consumption of alcohol to an increased risk of dementia. Apart from other brain damage that alcohol may cause, heavy drinking over an extended period can result in a shortage of vitamin B1 (thiamine). Thiamine is crucial for memory formation and thiamine deficiency has been linked to Alzheimer’s disease.
Moderate drinking (a daily glass of wine or pint of beer) does not appear to be a risk factor for dementia. On the other hand, claims that moderate alcohol consumption protects the brain from dementia appear to be unfounded.
- Eat a brain-healthy diet.
The medical and scientific communities generally agree that healthy eating patterns improve physical and mental health. Recent research has explored whether a specific diet can prevent or delay the onset of Alzheimer’s and other forms of dementia.
Food selections that seem to hold the most promise are the Mediterranean diet (heavy on fruits, vegetables, whole grains, legumes, fish and seafood, and unsaturated fats, but not red meat, eggs, and sweets) and the MIND (Mediterranean–DASH Intervention for Neurodegenerative Delay) diet (a modified version of the Mediterranean diet that prioritizes berries over other fruits and leafy greens over other vegetables). The MIND diet appears to slow cognitive decline after a stroke, while a 2023 study found “fewer signs of Alzheimer’s disease in the brains of older adults” who followed a Mediterranean or MIND diet.