Dementia Risk May Be Doubling, New Study Suggests

We all forget things now and then—people’s names, where you put your car keys, that dentist appointment that was scheduled before you got your new calendar. As we age, forgetfulness may worsen and begin to disrupt thinking abilities. This is referred to as mild cognitive impairment (MCI). While MCI can be annoying, it typically doesn’t interfere with being able to complete everyday tasks. With that said, MCI can also be an early warning sign of future dementia—more serious memory and cognitive impairments that interfere with everyday life. 

Several factors besides age can cause MCI, including a lack of quality sleep, medications, family history of Alzheimer’s and other types of dementia and conditions that raise the risk of heart disease—like high blood pressure and high cholesterol.

Historically, research has suggested 11% to 14% of men and 19% to 23% of women in the U.S. will develop dementia during their lifetimes. But researchers from several institutions, including NYU Langone Health, Johns Hopkins University and the Mayo Clinic, teamed up for a new study to challenge these numbers. Their findings, published in January 2025 in Nature Medicine, may surprise you.

How Was This Study Conducted?

Researchers pulled participant data from the Atherosclerosis Risk in Communities (ARIC) study, a long-running study from 1987 to 2020. There were just over 15,000 participants included in the study with an average age of 55 when the study began. All were free of dementia. About 27% of the participants were black, 55% were women, and approximately 31% of the participants carried at least one type of APOE4 gene—a gene variant that increases one’s genetic risk of developing Alzheimer’s disease.

Participants were followed for an average of 23 years. During that time, there were 3,252 cases of dementia. Dementia was diagnosed via several avenues, including in-person visits with cognitive testing (783 cases), through phone interviews (1,589 cases) and by reviewing hospital and death records (880 cases). 

What Did This Study Find?

After running several statistical analyses, key findings stood out to these researchers. 

• At age 55, the lifetime risk of dementia—up to age 95—was 42%. This risk remained low from ages 55 to 75 (about 4%) but dramatically increased after age 75. 
• Women had a higher lifetime risk of dementia compared to men (48% vs. 35%). 
• Black adults had a higher lifetime risk of dementia compared to white adults (44% vs. 41%).
• About 50% of the study participants who carried one APOE4 gene and 60% who had two copies of the gene developed dementia after midlife. They also developed dementia earlier than those without the gene variants—typically by age 70.

Based on these numbers, researchers predict that the current rate of dementia—514,000 cases of dementia per year—will nearly double to 1 million new cases per year by 2060. 

But why?

For starters, these researchers note that previous studies may not have accurately recorded the number of dementia cases. This is because, according to them, researchers previously relied on cognitive testing at study visits and medical and death records to identify dementia cases. But, they point out, people with cognitive impairments are less likely to attend in-person assessments, which means that many cases may have been missed, resulting in under-reporting.

Another reason is that the U.S. population is aging. The Baby Boomer generation, born from 1946 to 1964, is now in their 60s and 70s, with some entering their eighth decade. And there’s a reason they’re called Baby Boomers—there were a lot of babies born during that time, and now they are now in the final decades of life.

The researchers also surmise that Black people may have higher rates of dementia compared to white people due to comparatively lower socioeconomic conditions in which less education and lack of proper nutrition earlier in life may predispose them to higher rates of dementia later in life. As for women, they may have higher rates of dementia than men simply because women tend to live longer. The older you are, the higher your risk for dementia, so some men simply aren’t living long enough to develop dementia. 

How Does This Apply to Real Life?

Brain health is important at every age. We know that changes in the brain begin decades before symptoms of dementia show up. This means that prevention is a great, approachable goal—and it’s never too early to begin. 

There are also certain heart conditions that raise the risk of dementia—including atrial fibrillation, coronary heart disease and heart failure (a weakening of the heart muscle). So it makes sense that conditions that increase your risk of heart disease—high cholesterol, high blood pressure, obesity, diabetes—would also increase your risk of dementia. 

Another common denominator between heart and brain health is inflammation. Chronic inflammation is a culprit behind many diseases, including heart disease, cancer, diabetes, arthritis and, yes, dementia. 

Because of the heart-brain connection, it also makes sense that what’s good for one would be good for the other. For example, it’s been suggested that an anti-inflammatory diet is associated with a lower risk of cognitive impairment. One study has suggested that if you already have diabetes, heart disease or had a stroke, you may be able to lower your risk of dementia by a third if you eat an anti-inflammatory diet. 

What does an anti-inflammatory diet include? Put simply—lots of whole foods that provide fiber, healthy fats, lean protein and a wide spectrum of antioxidants, vitamins and minerals. More specifically, this includes whole grains, nuts, seeds, sources of lean protein, fruits, vegetables, legumes and healthy oils, like olive oil. This also includes sources of omega-3s, including seafood—salmon, tuna and shrimp—and plant-based sources—walnuts, flaxseeds and chia seeds. Fermented dairy, like yogurt and kefir, also fit into an anti-inflammatory meal pattern, as do herbs and spices.

Foods that tend to be inflammatory and should be limited or avoided include excessive added sugar, highly processed foods, processed meats and foods with artificial additives. And while the evidence is mixed, there is plenty to suggest alcohol increases dementia risk, too. 

The Mediterranean diet, DASH diet and MIND diet are all examples of anti-inflammatory diets. The MIND diet is a fusion of the Mediterranean and DASH diets and is specifically designed for brain health. If this all seems overwhelming, we’ve got plenty of recipes to help you get started on your brain health journey.

The Bottom Line

Researchers predict that dementia cases in the U.S. will double over the next 35 years. Healthy habits now can help stave off dementia and other cognitive issues later on. This includes eating a healthy diet with a variety of foods, engaging in regular physical activity, getting plenty of quality sleep, managing your stressors and spending time with people you love.