Alzheimer’s disease (AD) is on track to become one of the defining public health challenges of our time. Every three seconds, somewhere in the world, someone is diagnosed with dementia, and it’s usually Alzheimer’s disease.
Currently, approximately 50 million people worldwide have AD. By 2050, this number will exceed 130 million.
The human health and socioeconomic consequences of this are going to be immense. But perhaps it doesn’t have to be this way.
Preventing Alzheimer’s disease:A 2024 report from the influential Lancet Commission suggests that up to one-third of AD cases could be prevented simply by avoiding certain risk factors.
These 14 modifiable risk factors encompass: traumatic brain injury, hypertension, depression, diabetes, smoking, obesity, high cholesterol levels, low physical activity levels, too much alcohol consumption, too little education, vision loss, hearing loss, social isolation and air pollution.
While this comprehensive list is rooted soundly in science, it’s not easy for members of the general public to monitor and manage 14 separate health targets – especially when prevention efforts need to start decades before symptoms appear.
This is a problem that needs addressing. Tackling this problem requires a prevention model that is simple and memorable – something the public can easily embrace, understand and follow.
There are successful examples that can serve as a template. Stroke prevention associations, for instance, have successfully adopted the FAST (Face, Arm, Speech, Time) mnemonic to teach stroke warning signs. AD prevention needs a FAST equivalent.
SHIELD (Sleep, Head Injury prevention, Exercise, Learning and Diet) may fill that role. SHIELD brings together the most significant, overlapping dementia risk factors into five core pillars, offering a clear and effective strategy for prevention.
Sleep:Sleep is a foundational element of SHIELD. Maintaining healthy sleep habits is a key protective factor against dementia. Adequate sleep supports brain function, memory, mood and learning.
Insufficient (less than five hours per night) or poor-quality sleep (frequent awakenings), especially in midlife, increases the risk of cognitive decline and dementia. Chronic poor sleep leads to build-up in the brain of amyloid-beta protein, which is implicated in the development of AD.
Poor sleep also increases the likelihood of obesity, high blood pressure and depression, all risk factors for AD. If you’re currently sleeping four to five hours per night, consider changing this habit to avoid increasing your risk for developing dementia in later life. Sleep is a vital tool for brain protection and AD prevention.
Head injury:Head injury prevention is, rather surprisingly, often overlooked in conversations about dementia. There are strong links between traumatic brain injuries, including concussions, and higher AD risk. Such head injuries can occur in a wide variety of settings, not just professional sports. Intimate partner violence, for example, is unfortunately common in our society and is a frequent, but neglected, cause of head trauma.
Exercise: Exercise is perhaps the most powerful lifestyle habit for reducing the risk of AD. Exercise directly addresses multiple major risk factors, including obesity, high blood pressure, high cholesterol and depression. It also supports the growth of brain cells, memory and emotional health.
Exercise is not just “heart medicine,” but “brain medicine” too. Regular movement, even in small amounts, enables better brain aging and can help avoid AD.
Learning:Learning, both in and out of school, remains one of the strongest protective factors against dementia. Lower educational levels, such as not finishing secondary school, are linked to a significantly increased risk for dementia. Learning contributes to the brain’s “cognitive reserve,” which is the brain’s ability to function well despite damage or disease.
Individuals with AD maintained better mental function if they had continued learning throughout life. Public health messaging should promote life-long learning in all forms – from reading and language learning to engaging hobbies that keep the brain active. It’s never too early (or too late) to learn another language or to challenge your brain. Boosting your cognitive reserve boosts your brain against AD.
Diet:Diet also plays a major role in brain health and dementia prevention. No single food prevents dementia. Rather, a combination of nutrient-rich foods supports overall brain health. A healthy diet can lower dementia risk by emphasizing whole foods like fruits, vegetables, whole grains, nuts and fish, while restricting processed foods, red meat and sweets.
By simplifying the science, the SHIELD framework offers a realistic and research-backed approach to brain health. Until a cure is discovered, prevention is the strongest tool. Concepts like SHIELD provide a starting point for achievable prevention. (The Conversation)
