How keeping a healthy heart is key to ward off Alzheimer's, dementia risk

London, Sep 5 (IANS) Maintaining proper heart health will not only keep cardiovascular diseases at bay, but also preserve brain metabolism -- key to ward off the risk of Alzheimer’s and dementia, suggests a study.

The study by scientists at the Centro Nacional de Investigaciones Cardiovasculares (CNIC) in Madrid, Spain, confirm the importance of controlling traditional cardiovascular risk factors, such as hypertension, cholesterol, diabetes, smoking, and a sedentary lifestyle, which will preserve cardiovascular health, and also prevent Alzheimer’s disease and
other dementias. 

Published in The Lancet Healthy Longevity, the study shows that atherosclerosis -- the accumulation of fatty deposits in the arteries -- and its associated risk factors, in addition to being the main cause of cardiovascular disease, are also implicated in the cerebral alterations typically found in Alzheimer’s disease, the most frequent cause of dementia.

According to CNIC General Director Dr Valentín Fuster, the new findings are important because they open up the possibility of treating a modifiable disorder (cardiovascular disease) to prevent the development of a disease for which there is currently no curative treatment (dementia).

“The sooner we act to control cardiovascular risk factors, the better it is for our brain health. Everybody knows that a healthy lifestyle and controlling cardiovascular risk factors are important for preventing a heart attack.

“Nevertheless, the additional information linking the same risk factors to a decline in brain health could further increase awareness of the need to acquire healthy habits from the earliest life stages,” Dr Fuster said.

In the study, the team, using imaging techniques such as positron emission tomography (PET), detected a more pronounced reduction in cerebral glucose metabolism among more than 4,000 asymptomatic middle-aged individuals who maintained a high cardiovascular risk.

“In participants with a sustained high cardiovascular risk, the decline in cerebral metabolism was three times greater than in participants who maintained a low cardiovascular risk,” said Catarina Tristão-Pereira, a doctoral student.

Glucose is the main energy source for neurons and other brain cells. “If there is a sustained decline in cerebral glucose consumption over several years, this may limit the brain's ability to withstand neurodegenerative or cerebrovascular diseases in the future,” explained Dr.  Juan Domingo Gispert, an expert in neuroimaging at the CNIC.

The researchers discovered that the individuals showing this metabolic decline already show signs of neuronal injury. “This is a particularly important finding because neuronal death is irreversible,” said Dr Cortes Canteli, a neuroscientist at the CNIC.

The team also discovered that the progression of subclinical atherosclerosis in the carotid arteries over 5 years is linked to a metabolic decline in brain regions vulnerable to Alzheimer’s disease, in addition to the effect of cardiovascular risk factors.

The scientists conclude that in light of these results, “carotid screening has great potential to identify individuals at risk of cerebral alterations and cognitive decline in the future.”