Nature vs nurture: Which matters most when it comes to heart and brain health?

While the link between good cardiovascular health and brain health is well known, two studies have now taken a closer look at the link between a healthy heart and cognitive function as we age – and the findings are fascinating.

For the majority of people, the condition of their heart is not often something that crosses their mind until they either encounter a problem, or enter middle or later life. However the first study revealed that the condition our heart is in as early as our 30s can impact our risk of developing dementia in our 60s and 70s.

A team of researchers, whose work was published in the JAMA Neurology and reported by MedPage Today, looked at whether the Framingham risk score – a formula used to estimate cardiovascular risk – could predict brain issues in later life.

The study of almost 500 people showed that, while vascular risk increased with age, higher vascular risk scores were associated with smaller whole-brain volumes and higher white matter-hyperintensity volume (which are lesions in the brain) at all ages, with the largest effect sizes at age 36.

According to author Sudha Seshadri, the study makes a strong case for addressing vascular risk as early as our 30s, as well as looking at the effect that perinatal, early-childhood and adolescent factors could have on an individual’s dementia risk.

But while it’s clear that there is a link between our tickers and brain matter, another recent study delved further into the issue to determine whether a person’s genetics, aka their nature, plays more of a role in heart and brain health, or whether it’s more attributable to the way we’re brought up and behave.

Academics from Emory University studied pairs of twin brothers in a bid to see whether human nature or nurture had a greater influence on cardiovascular health and a person’s cognitive performance. Twins were chosen as the subjects of the study as researchers can better examine the role of genes and environment, due to the fact that identical twins share 100 per cent of their genetic material, while fraternal twins on average share only half. This makes twin studies perfect for studying ‘nature versus nurture’.

“Our study across the entire sample of twins confirmed that better CVH is associated with better cognitive health in several domains,” senior author Viola Vaccarino, from Emory University School of Medicine, said.

In a bid to determine whether familial factors between twins were down to genetics or environmentally driven, researchers then looked at whether the relationship between cardiovascular health and cognitive function was different between identical and fraternal twins. This found that environmental factors such as socioeconomic status, education and parenting were important precursors of heart health and brain health, rather than genetics.

Co-author Ambar Kulshreshtha added: “Because CVH [cardiovascular health] factors are modifiable, prevention of cardiovascular risk factors and promotion of a healthy lifestyle beginning early in life should achieve the best results for promoting not only cardiovascular health, but also cognitive health.”