How Can We Age Better? Neuroscience Insights for Preventing Alzheimer’s

Neuroscientist Eider Arenaza-Urquijo (ISGlobal) explains which factors increase or reduce the risk of Alzheimer’s and how gender, stress, and physical activity play a role.

Why are 2 out of 3 people with Alzheimer’s women? What role do physical activity, education level, or stress play in our brain health? We spoke with neuroscientist Eider Arenaza-Urquijo (ISGlobal) about the latest findings in Alzheimer’s prevention: from the impact of inequality to how midlife exercise can protect us.

You can watch the full interview here:

14 modifiable risk factors for dementia

Science has identified 14 modifiable risk factors that could explain up to 45% of dementia cases. Therefore, there is enormous prevention potential. Among them are low education levels, physical inactivity in midlife, vascular risk factors, or exposure to air pollution.

Women and Alzheimer’s: inequality and brain health

For years it was thought that the fact that two out of three people with Alzheimer’s are women was simply due to their greater longevity, since age is the biggest risk factor for developing Alzheimer’s. But studies suggest there is more to it. Research is starting to explore whether men and women may develop the disease through different biological mechanisms. The menopausal transition may play a role, with brain and vascular changes, but more studies are needed.

Gender inequalities also matter. For example, women have historically had less access to education and physical activity, and face a higher risk of mental health issues. In addition, most caregivers of people with Alzheimer’s are women, which exposes them to depression and social isolation—both risk factors for developing the disease.

Physical activity: a protective factor

Changes associated with Alzheimer’s can begin up to 20 years before symptoms appear. That is why physical activity in midlife is key.

A study of more than 300 people with a family history showed that those who went from sedentary to active accumulated less amyloid protein in the brain, the first to appear in the disease. Those who remained sedentary during those four years showed reduced cortical thickness in memory-related areas. And vigorous exercise is not necessary: walking, swimming, or climbing stairs all count.

Life stress and Alzheimer’s risk

Depression is a risk factor for dementia. That is why the idea is to try to prevent it. We know that living stressful life events, such as losing a partner, facing financial problems, or being a victim of abuse, increases the risk of depression and, therefore, Alzheimer’s.

A recent study found that the accumulation of stressful events throughout life was associated with pathological changes linked to Alzheimer’s in people who developed anxiety or depression. Another study found that grieving the loss of a partner is associated with pathological changes linked to Alzheimer’s, while unemployment and financial loss were linked to brain atrophy in regions related to emotional or stress response.

Education and cognitive reserve

A higher level of education is associated with better-preserved brains in old age: improved connectivity and greater ability to compensate for the buildup of pathological proteins. Studies show that some people can die with Alzheimer’s pathology in their brains without ever developing clinical symptoms. These individuals have greater cognitive reserve, and higher education is one factor that promotes this reserve, allowing the brain to compensate for pathological changes and maintain normal function.

The ‘superagers’: exceptional memory at 80

There are people over 80 with memory comparable to that of much younger individuals. They are called superagers, and many studies are now focused on them. They represent a small percentage of the population, but they help us understand the different ways of aging. Beyond genetics, maintaining cognitive, physical, and social activity has been shown to help preserve the brain. As the saying goes: what’s good for the heart is good for the brain.

Ongoing studies: urban environment and dementia

The team led by Eider Arenaza-Urquijo is studying how the urban environment influences brain health. Walking more thanks to pedestrian-friendly neighborhoods, having more social contact, or enjoying quality sleep (without excess noise) can make a difference in brain aging.

In short, preventing Alzheimer’s is partly in our hands, but also depends on the social and environmental conditions around us. Science is advancing to identify what we can change—both individually and collectively—to age in the best possible way.