We all forget things from time to time: 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 can worsen and begin to disrupt thinking skills. This is called mild cognitive impairment (MCI). Although MCI can be annoying, it usually does not interfere with the ability to perform daily tasks. That said, MCI can also be a warning sign of future dementia – more serious memory and cognitive impairments that interfere with daily life.
Besides age, several factors can cause MCI, including lack of quality sleep, medications, family history of Alzheimer’s disease and other types of dementia, and conditions that increase the risk of heart disease. such as high blood pressure and high cholesterol.
Historically, research suggests that 11 to 14 percent of men and 19 to 23 percent of women in the United States will develop dementia during their lifetime. But researchers from several institutions, including NYU Langone Health, Johns Hopkins University and the Mayo Clinic, teamed up for a new study aimed at disputing those numbers. Their conclusions, published in January 2025 in Natural medicinemight surprise you.
How was this study carried out?
Researchers extracted data from participants in the Atherosclerosis Risk in Communities (ARIC) study, a long-term study from 1987 to 2020. Just over 15,000 participants were included in the study, with an average age of 55 years old at the start of the study. Not everyone had dementia. About 27% of participants were black, 55% were women, and about 31% of participants carried at least one type of APOE4 gene, a genetic variant that increases the genetic risk of developing Alzheimer’s disease.
Participants were followed for an average of 23 years. During this period, there were 3,252 cases of dementia. Dementia was diagnosed by several means, including in-person visits with cognitive testing (783 cases), telephone interviews (1,589 cases), and review of hospital and death records (880 cases).
What did this study reveal?
After carrying out several statistical analyses, the main results caught the attention of these researchers.
- At age 55, the lifetime risk of dementia – up to age 95 – was 42%. This risk remains low between the ages of 55 and 75 (around 4%) but increases considerably after the age of 75.
- Women had a higher lifetime risk of dementia than men (48% versus 35%).
- Black adults had a higher lifetime risk of dementia than white adults (44% versus 41%).
- About 50% of 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 genetic variants, usually around age 70.
Based on these figures, researchers predict that the current rate of dementia – 514,000 cases of dementia per year – will almost double to 1 million new cases per year by 2060.
But why?
To begin, these researchers note that previous studies may not have accurately recorded the number of dementia cases. Indeed, they say, researchers previously relied on cognitive tests during study visits and medical and death records to identify cases of dementia. But, they point out, people with cognitive disabilities are less likely to show up for in-person assessments, meaning many cases may have been missed, leading to underreporting.
Another reason is the aging of the American population. The baby boomer generation, born between 1946 and 1964, is now between 60 and 70 years old, and some are entering their eighth decade. And there’s a reason they’re called baby boomers: Many babies were born during this time, and they are now in the final decades of their lives.
Researchers also hypothesize that blacks may have higher rates of dementia than whites due to comparatively lower socioeconomic conditions in which less education and a lack of adequate nutrition earlier in life may predispose them to severe higher rates of dementia later in life. As for women, they may have higher rates of dementia than men simply because they tend to live longer. The older you are, the higher your risk of dementia, so some men simply don’t live long enough to develop dementia.
How does this apply to real life?
Brain health is important at any age. We know that changes in the brain begin decades before symptoms of dementia appear. This means that prevention is an ambitious and attainable goal, and it is never too early to start.
Certain heart conditions also increase 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—also increase your risk of dementia.
Inflammation is another common denominator between heart and brain health. Chronic inflammation is the root cause of many diseases, including heart disease, cancer, diabetes, arthritis and, of course, dementia.
Because of the heart-brain connection, it also makes sense that what is good for one is good for the other. For example, it has been suggested that an anti-inflammatory diet may be associated with a lower risk of cognitive impairment. One study suggested that if you already have diabetes, heart disease or have suffered a stroke, you could reduce your risk of dementia by a third if you follow an anti-inflammatory diet.
What does an anti-inflammatory diet include? Simply put, many whole foods provide fiber, healthy fats, lean protein, and a broad spectrum of antioxidants, vitamins, and minerals. Specifically, this includes whole grains, nuts, seeds, lean protein sources, fruits, vegetables, legumes, and healthy oils, like olive oil. This also includes sources of omega-3, including seafood (salmon, tuna and shrimp) and plant sources (walnuts, flax seeds and chia seeds). Fermented dairy products, like yogurt and kefir, also fit into an anti-inflammatory diet, 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 although the evidence is mixed, there is plenty of evidence to suggest that alcohol also increases the risk of dementia.
The Mediterranean diet, the DASH diet, and the 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 have plenty of recipes to help you start your brain health journey.
The essentials
Researchers predict that dementia cases in the United States will double over the next 35 years. Healthy habits now can help prevent dementia and other cognitive problems later. This involves eating a healthy diet with a variety of foods, engaging in regular physical activity, getting enough quality sleep, managing your stressors, and spending time with the people you love.
