Green Neighbourhood decreases risk of heart disease: JAHA

Louisville, Kentucky: Living more close to nature may make your heart healthier, suggests a new study.

The study, published in the Journal of the American Heart Association, finds that people living in neighbourhoods with lots of greenery may have a lower risk of strokes and heart disease.

Environmental issues are undoubtedly the challenge of the 21^st century. Previous studies have shown the positive impact of green vegetation on health, however, the pathophysiological processes affected by vegetation exposure is still not clear. In this, the first of its kind study, Aruni Bhatnagar, professor of medicine and director of the University of Louisville Diabetes and Obesity Center, and colleagues investigated the impact of neighbourhood greenspaces on individual-level markers of stress and cardiovascular disease risk.

For the study, the researchers collected blood and urine samples for over five-years from 408 people of varying ages, ethnicities and socioeconomic levels. The risk of cardiovascular disease was calculated using biomarkers measured from blood and urine samples. The participants, recruited from the University of Louisville's outpatient cardiology clinic, were at increased risk of developing cardiovascular disease.

Greenspaces' density near the participant's residences was measured using the Normalized Difference Vegetation Index (NDVI), a tool that indicates levels of vegetation density created from satellite imagery collected by NASA and USGS. The levels of air pollution was assessed using particulate matter from the EPA and roadway exposure measurements.

Key Findings:

• Living in areas with more green vegetation was associated with:
  
  
  
  • lower urinary levels of epinephrine, indicating lower levels of stress;
  
  
  • lower urinary levels of F2-isoprostane, indicating better health (less oxidative stress);
  
  
  • higher capacity to repair blood vessels.
  
  
  
  


• Associations with epinephrine were stronger among women, study participants not taking beta-blockers -- which reduce the heart's workload and lower blood pressure -- and people who had not previously had a heart attack.


• Of the 15 subtypes of circulating angiogenic cells examined, 11 were inversely associated, whereas 2 were positively associated with contemporaneous NDVI.

"Our study shows that living in a neighbourhood dense with trees, bushes, and other green vegetation may be good for the health of your heart and blood vessels," said Bhatnagar. "Indeed, increasing the amount of vegetation in a neighbourhood may be an unrecognized environmental influence on cardiovascular health and a potentially significant public health intervention."

"Residential greenness is associated with lower levels of sympathetic activation, reduced oxidative stress, and higher angiogenic capacity," write the authors.

"These findings were independent of age, sex, ethnicity, smoking status, neighbourhood deprivation, use of statin medications and roadway exposure," they conclude.

For further reference follow the link: https://doi.org/10.1161/JAHA.118.009117