Dementia can be prevented in part because some risk factors that can be acted upon. Others, however, cannot be changed. The main one is age. After the age of 65, the risk of dementia increases. Another important factor is sex: women are more at risk of suffering from Alzheimer’s. And then there are the genetic factors that we cannot change either: it is known, for example, that people who carry the 4 allele of the apolipoprotein E (ApoE) gene are between two and three times more at risk of suffering from Alzheimer’s. There are other genetic factors associated with early onset dementia, such as the so-called “familial Alzheimer’s,” which appears in younger people and represents approximately 1% of all dementia patients.
We cannot change our age, sex and genetics, but there are other factors that we can do something about. These are modifiable factors, and we know more and more about them.
For example, a low educational level is a risk factor for dementia. For this reason, educating oneself and keeping the brain active provides a protection that we call “cognitive reserve.” When it comes to preventing dementia, the advice is to continue to learn new things, such as a language.
Vascular risk factors, such as hypertension, are also linked to dementia. Middle-aged adults who have hypertension have a higher risk of suffering from dementia in the future. And the same goes for obesity; obese adults in midlife are also at higher risk of having dementia later in life. Diabetes is another very important risk factor. People with type 2 diabetes are two to three times more at risk than non-diabetics. Smoking and alcohol consumption also increase the risk of Alzheimer’s.
But some vascular risk factors can be addressed. For example, maintaining a Mediterranean diet has been found to reduce the risk of dementia, as it reduces the vascular risk factors. In other words, if you prevent high blood pressure, obesity and diabetes via your diet, you will also reduce the risk of dementia. The other protective factor is physical exercise, because it also reduces those vascular risk factors.
Other factors can also affect dementia, such as depression. It is not known whether depression is the cause or effect of dementia. But studies show that it is common for dementia patients to suffer depression even before the onset of their symptoms. While it’s a complex relationship, depression is also identified as a risk factor.
And then there are other factors such as social isolation, which is also a proven risk factor. That is why older people are advised to remain socially engaged. People who suffer from hearing loss are also at greater risk of dementia, as this condition can lead to social isolation.
Natalia García Casares is a neurologist, tenured professor and researcher at the Faculty of Medicine of the University of Malaga, an expert in cognitive neurology and dementia.