People who have gene variants that predispose them to dementia can reduce their risk significantly by maintaining good cardiovascular health, suggests research from Boston University.
As reported in the journal in the journal Neurology, the researchers assessed the cardiovascular health of 1211 participants of the Framingham Heart Study offspring cohort, a long-term epidemiological study set up in the 70’s, at an average age of 55 years. Ideal cardiovascular health was defined by the American Heart Association guidelines, which requires people to be nonsmokers, have a healthy body mass index, a good diet and exercise regularly, as well as having healthy blood pressure, cholesterol and glucose levels.
The participants of the cohort had previously been genotyped for 23 genetic variants that are known to increase a person’s risk for Alzheimer’s disease and other forms of dementia, as well as the APOE e4 variant that is also linked to increased risk for Alzheimer’s disease and found in 10-15% of the population.
The cohort was checked for symptoms of dementia approximately 7 years after their cardiovascular health was assessed. Those with a high genetic risk score (80th percentile or higher) for dementia were 2.6-times more likely to develop dementia than individuals with low risk (20th percentile or lower). Similarly, if people had one copy of the APOE e4 variant they were more than twice as likely to develop dementia than those with no copies.
However, if participants in the cohort had good cardiovascular health it reduced their risk for developing dementia by 55% compared with those with poor heart health regardless of whether they had a high genetic risk or not. The effects of the genes and cardiovascular health did not appear to be linked, although the researchers cautioned in the paper that the analysis was underpowered to detect such associations.
“Just because you have a high genetic risk of dementia doesn’t mean that you can’t lower your risk by adopting a healthier lifestyle,” commented lead author Gina Peloso, PhD, assistant professor of biostatistics at the Boston University School of Public Health.
It’s thought that around 35% of dementia cases could potentially be avoided by changing risk factors such as an unhealthy lifestyle. Several previous studies have shown a link between poor heart health and dementia, but the impact of genetics in addition to cardiovascular health was less clear.
“Our data suggests that persons with high genetic risk, that is individuals with either an APOE e4 allele or a high genetic risk score, may gain by adopting healthy cardiovascular health behaviors,” write the researchers.