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Around 6 million people have Alzheimer’s disease in the U.S., according to the Centers for Disease Control and Prevention, and this number is rapidly increasing. By 2060, it’s projected to hit 14 million.
Solutions are urgent. In some sense, research investment reflects that: Over the past 30 years, there’s been a flurry of funds and resources invested into research on aging, and in particular Alzheimer’s disease. For example, the U.S. Department of Health and Human Services’ National Plan to Address Alzheimer’s Disease, created in 2012, aims to prevent and effectively treat Alzheimer’s and related dementias by 2025—a very ambitious goal. The fiscal year 2022 budget of the National Institute on Aging, part of the National Institutes of Health, is more than $4 billion, a big increase from its 2016 budget of around $1.6 billion.
This research is crucial, but it also has a problem, if we hope to really prevent Alzheimer’s. The majority of funds are focused on research into later adulthood (65 and up), with less emphasis on early and middle adulthood. There’s a certain logic to this: Studies have shown that our brains shrink when we get older, and after we hit 65 our brains start to change structurally, and cognitive decline follows.
This belief is not wrong, but it also doesn’t reflect the whole picture. Research has also shown that our brains age much earlier than we tend to think. You don’t wake up at 65 or 70 with an aged brain: It’s a gradual process that starts much sooner.
In one study, for example, researchers investigated changes in the thickness of the cortex (the wrinkled outer layer of the brain) and in volume (overall number of brain cells) in adults age 23 to 87. They looked at these changes after an average interval of 3.6 years. Results showed gradual reductions in volume and thickness across the mixed age cohort—not just among the older adults. Similarly, in a study of 1,037 participants born in 1972 or 1973 who had not yet developed age-related diseases, researchers quantified the pace of aging by tracking declining function across the cardiovascular, metabolic, renal, immune, dental, and pulmonary systems. Results showed that before age 40, individuals who were aging more rapidly were less physically able, self-reported worse health, looked older, and showed cognitive decline and brain aging (e.g., thinner average cortical thickness). Another study with the same group of people found that at 45, the adults with a faster pace of aging had more cognitive difficulties, signs of advanced brain aging, diminished sensory-motor functions, older appearance, and more pessimistic perceptions of aging.
Taken together, these results suggest that just as we age physically, the brain starts to age in youth and midlife. This aging starts much earlier than we’ve long thought. A recent brain imaging study with a total of 101,457 participants showed that the volumes of both cerebrum grey matter and subcortical grey matter, the brain cell bodies involved in functions such as perception, cognition, emotions, and self-control, start to reduce after 7 and 17 years old, respectively. White matter—made up of the connections between neurons that allow for communication between brain regions—starts to decline at 40 years old.
The young brain is highly plastic—readily open to change—and sensitive to learning and training. Research has shown that mindfulness, exercise, nutrition, and cognitive training, among other activities, induce positive functional and structural brain changes. It doesn’t take as much work as you might think to make positive changes. For example, one form of mindfulness training, integrative body-mind training (which emphasizes awareness and acceptance of the body and mind in the moment), induces functional changes in young adult brains after only five 20- to 30-minute sessions. White matter and gray matter structural changes occur in the brain’s self-control and reward networks after 10 to 20 sessions of 30 minutes.
Our brains maintain this plasticity and can be shaped by learning and training even during midlife and later adulthood, though the process often takes longer. In a 10-year study, a midlife cohort (with a mean age of 54) received either mindfulness training or physical exercise. Results showed that mindfulness induced greater functional and structural changes in the brain’s self-control and reward networks. Moreover, the study showed that the mindfulness group also had reduced levels of stress hormone, improved immune function, and better quality of life. Another study showed that some older adults (60 to 80 years old) still maintain youthful memory and brains, and associated this preserved memory with preserved brain structure in the anterior and posterior cingulate cortex and prefrontal cortex, which are associated with attention and self-control processes. These results may suggest that brain self-control networks are crucial for slowing down aging and preventing cognitive decline.
Taken together, these studies suggest that early prevention and intervention in young and midlife adults may be crucial to prevent and ease the burden of age-related disorders like Alzheimer’s. We should especially focus on approaches that strengthen brain self-control and reward networks. In order to improve and build upon these interventions, research priorities need to reflect the fact that age-related diseases like Alzheimer’s and dementia involve gradual damage to the brain and body, beginning in early and mid-life.
Broadening our understanding of the window of action for prevention and treatment will save money, resources, and lives. We can start with raising awareness of early brain aging through social media and other conversations; federal agencies such as NIH and aging-related private agencies and organizations should also increase funding opportunities to support early prevention and intervention research. In its 2020–25 Strategic Directions for Research, the National Institute on Aging highlighted early prevention and lifespan-long interventions, which is a promising step—but more can certainly be done.
There’s a clear path forward, but no time to wait. By 2050, according to WHO, 22 percent of the world’s population will be over 60 (up from 12 percent in 2015). The window to reach them while their brains are still ripe for change is closing quickly.
State of Mind is a partnership of Slate and Arizona State University that offers a practical look at our mental health system—and how to make it better.