The human brain is amazing. It contains about 86 billion (86,000,000,000!) neurons that are connected to each other. These neurons work together and make it possible for us to live and thrive.
Our neurons and the connections between them are always changing. Some connections fade away over time, and other ones are created or get stronger. This process in which the brain changes and adapts is called neuroplasticity. We can use our brain’s natural neuroplasticity to help fight against brain disease.
Dementia is a brain disease that causes our neurons and the connections between them to die. The most common cause of dementia is Alzheimer’s disease. About one in ten people will develop Alzheimer’s or dementia – which means you probably know someone who is affected.
There are many choices we make in our everyday lives that have an impact on our neurons and brain health over time. Some things – like exercise, lifelong education, and social connection – help keep our brains strong and resilient. Other things – like depression, smoking, high blood pressure, and diabetes – can be harmful to brain health, especially if they are not well managed.
Our landmark 2011 Lancet Neurology publication was the first study ever to estimate that up to half of Alzheimer’s and dementia may be preventable by living a healthy lifestyle. We found that relatively small reductions of 10% to 25% in these risk factors in society could potentially prevent millions of people from developing symptoms of dementia or Alzheimer’s.
We also have found that some risk factors matter more than others in different groups. In our 2022 JAMA Neurology publication, the most important risk factors were low education for Hispanic or Latino individuals, physical inactivity for Asian individuals, and obesity for other race/ethnicity groups.
The results of the Barnes & Yaffe study have been confirmed and extended by many other groups including the Lancet Commission and the World Health Organization and serve as the foundation for public health policy worldwide to reduce dementia risk.
There are now 14 recognized modifiable dementia risk factors: low education, physical inactivity, smoking, depression, high blood pressure, diabetes, obesity, hearing loss, high cholesterol, traumatic brain injury, high alcohol consumption, vision loss, social isolation, and air pollution.