Metabolic syndrome, or insulin resistance syndrome as it is also called, means that you have at least three of five risk factors: too much fat around the waist, high blood pressure, high blood sugar, high levels of the body's most common blood fat triglycerides and low levels of the good HDL cholesterol. Approximately 25 percent of all adults are affected, says Abigail Dove, postdoctoral fellow at the Aging Research Center at Karolinska Institutet:
"It's enough to have slightly elevated values, for example in terms of blood sugar, for it to contribute to the syndrome. So you don't have to have full-blown diabetes for it to accelerate brain aging," she says.
The study - which looked at brain scans and blood samples from over 27,000 people - found that people with three of the risk factors had brains that were about a year older than their actual age.
With four of the factors, the brain was 1.7 years older and with all five, 2.3 years older.
Each individual factor by itself was also linked to premature brain aging.
"We believe this contributes to chronic inflammation that drives brain aging. In the long term, it may increase the risk of dementia," says Abigail Dove.
She says that the inflammation is suspected of damaging blood vessels and triggering harmful proteins in the brain.
Just by removing just one of these factors, you can slow down premature brain aging. The more you remove, the better, but all are valuable for brain health, says Abigail Dove.
The study is published in the journal Alzheimer's & Dementia.
Metabolic syndrome is not a disease but a group of risk factors such as high blood sugar, high blood pressure, belly fat, low levels of the “good” HDL cholesterol, and high triglycerides (blood fats).
The “diagnosis” is made if you have at least three of the five risk factors.
Each of them has health risks in itself, but together they exacerbate each other.
All five factors can be improved with healthy habits such as regular exercise, good nutrition and good sleep.
There are several explanations for why the syndrome accelerates brain aging. One is that it contributes to atherosclerosis and chronic inflammation in the body.
The fact that the brain is a couple of years older may not sound that serious, but having a higher brain age in relation to chronological age can increase the risk of cognitive decline and dementia.
Source: Abigail Dove, Karolinska Institutet.
