"Perceived neighbourhood social cohesion could be a type of social support that is available in the neighbourhood social environment outside the realm of family and friends," said researchers from University of Michigan in the US.

For the study, the researchers tracked the cardiovascular health of over 5,000 US adults with no known heart problems over a period of four years, starting in 2006. Their average age was 70, and almost two thirds were women and married.

All the study participants were taking part in the Health and Retirement Study, a nationally representative study of US adults over the age of 50, who are surveyed every two years.

During the four year monitoring period, 148 of the 5,276 participants (66 women and 82 men) had a heart attack.

Analysis of the data showed that each standard deviation increase in perceived neighbourhood social cohesion was associated with a 22 percent reduced risk of a heart attack.

When put another way on the seven-point scale, each unit increase in neighbourhood social cohesion was associated with a 17 percent reduced risk of heart attack.

This association held true even after adjusting for relevant sociodemographic, behavioural, biological, and psychosocial factors, as well as individual-level social support.

The study appeared in the Journal of Epidemiology and Community Health.