Plus, the habit that comes in second—according to a neuropsychologist.
More than six million Americans are living with Alzheimer's Disease, the most common form of dementia, according to a 2023 Alzheimer's Association report. The report also notes that Alzheimer's starts about 20 years or more before a person develops memory loss or other hallmark symptoms of the devastating disease.
Damage to the brain cells causes dementia. Genetics can play a role, so it's not possible to prevent it 100 percent. But research discussed at the 2019 Alzheimer’s Association International Conference indicated that lifestyle choices can reduce the risk of cognitive decline and dementia.
"Research shows that keeping our mind sharp by continued learning and cognitive challenge can help our brains remain healthier as we age," says Dr. Jessica Caldwell, Ph.D., the director of the Women's Alzheimer's Movement Prevention Center at Cleveland Clinic.
It's like lifting weights—you do it to keep your muscles strong.
"Although the process of keeping your mind sharp is different from keeping your muscles strong, the phrase 'use it or lose it' can be applied to the brain as well as the body," Dr. Caldwell says. "The types of thinking-based activities involved in keeping your mind sharp—for example, attending classes, learning languages and debating topics—may also offer benefits for our mental health, as we feel a sense of accomplishment, and may offer opportunities to socialize, which is another way of reducing dementia risks."
But you may be surprised by her top daily tip for reducing dementia risk.
What Is the No. 1 Tip for Keeping the Mind Sharp?
You may have heard that exercises like crossword puzzles, word searches or Sudoku can help keep the mind sharp. And while they certainly won't hurt, the very best way to prevent cognitive decline is a different type of exercise: physical exercise.
"Some people are surprised to hear it, but we know that exercise has both immediate and long-term brain benefits, from increasing brain chemistry that supports the health of your brain cells to reducing factors such as chronic bodily inflammation, which can be harmful to the brain," Dr. Caldwell says.
Physical activity also has some sneaky perks for cognition.
"Exercise also has benefits for the brain that are indirect—for example, improving mood and sleep, reducing stress, supporting heart health and increasing chances to socialize, all of which, in turn, reduces risks for poor memory with age," Dr. Caldwell says.
Beyond prevention, a 2020 study conducted on mice indicated that exercise may even reverse age-related cognitive decline, but more research is needed on duration, frequency and exercise types to fully understand how this applies to humans. A review of previous research from the same year also suggested that physical activity could reduce cognitive decline and lower behavioral issues in individuals with mild cognitive impairment (MCI) or dementia. The authors suggested moderate-intensity (or greater) aerobic exercise would have the most significant effect on cognition.
How Can I Get More Exercise To Keep My Mind Sharp?
Though more research is needed on exercise and cognition, Dr. Caldwell says the American Heart Association's guidelines provide a good baseline.
"The goal for exercise for brain health for life is at least 150 minutes of moderate-intensity exercise [per week], and for healthy adults, more is better," Dr. Caldwell says.
If you aren't currently exercising, talk to your doctor first. From there, Dr. Caldwell says you can increase your physical activity—and your chances of making it a habit—with two big tips.
"First, pair exercise with something you like or already do. Think stationary biking while watching a favorite program or walking while listening to a podcast episode," Dr. Caldwell says. "Second, find a partner for accountability and motivation."
Your accountability partner can motivate you from afar. "Even if you can't find an in-person partner for runs or visits to the gym, checking in with a long-distance friend regularly about fitness goals can offer support and make it more likely that you will stick with your goals," Dr. Caldwell says.
What Are Other Ways To Reduce Cognitive Decline Risk?
Regular physical activity is important, but Dr. Caldwell says fighting cognitive decline requires a multi-prong approach.
She says it's also important to prioritize getting seven to eight hours of continuous sleep. "Sleep is when we cement new memories into long-term storage, and also when our brains have a chance to clear debris, including the types of proteins that build up in Alzheimer's disease," Dr. Caldwell says.
Research published in 2021 underscores the importance of sleep for brain health. The study, which was conducted on 8,000 British people aged 50 and over, indicated that people in their 50s and 60s who got six hours of shuteye or less per night were 30 percent more likely to be diagnosed with dementia than their peers, who were getting a least seven hours of sleep nightly.
Alcohol intake is another lifestyle habit to evaluate. "Our bodies process alcohol differently as we age, and drinking more than seven drinks per week has been linked to risk for dementia," Dr. Caldwell says.
Finally, don't put your mental health on the back burner. "Depression is a risk factor for dementia, and those feelings of sadness and lack of interest that can come with depression can also make it difficult to engage in other brain-healthy behaviors," Dr. Caldwell says.
What Are Signs of Cognitive Decline?
You can't remember if you brushed your teeth today. Should you be concerned? Probably not.
"Anyone can make a memory mistake at any age—some forgetfulness is normal," Dr. Caldwell says. "Signs of memory decline would include forgetting what happens frequently, such as needing several reminders throughout the day about a conversation you had that morning. Another sign would be forgetting essential information, such as forgetting the name of a loved one or an event you looked forward to."
If you notice these signs, Dr. Caldwell suggests seeing a doctor. "A primary care doctor may give you or your loved one a short memory test—one that takes about five minutes," Dr. Caldwell says.
From there, your doctor may suggest additional testing or appointments. Dr. Caldwell says this workup may include bloodwork, a brain scan, a referral to a neurologist who specializes in memory problems, or a referral to a neuropsychologist, like Dr. Caldwell.
"This is a specialist in memory and other thinking skills, who will administer several hours of paper or computer tests to better understand if you or your loved one are having a change in your thinking compared to others your age," Dr. Caldwell explains.
No matter what type of appointments and tests you or your loved one get, the goal is to get to a diagnosis—whether that is normal memory, some mild changes called mild cognitive impairment, or more significant changes, called dementia.
"Memory changes can appear for many reasons, and your doctor will talk with you about possible reasons for your diagnosis, though figuring that all out may take time," Dr. Caldwell says.
Dr. Jessica Caldwell, Ph.D., director of the Women's Alzheimer's Movement Prevention Center at Cleveland Clinic.