Green Areas Lower Health Inequities Between Rich, Poor
THURSDAY Nov. 6, 2008 -- Health inequalities between rich and poor people are much lower in areas that have lots of green space, such as parks, forests and playing fields, a large British study finds.
Dr. Richard Mitchell, of the University of Glasgow, and his colleagues noted that previous studies have shown that the presence of green space has an independent beneficial effect on health and health-related behaviors. They wanted to examine whether access to green space might also affect income-related health disparities.
Mitchell and his team looked at the almost 41 million people in England below retirement age and obtained individual death records for 366,348 people to determine the association between exposure to green space, income, all-cause mortality, and cause-specific death (circulatory disease, lung cancer and suicide) from 2001 to 2005.
In areas with the most green space, the health gap between the richest and poorest people was about half as large as that in the least green areas -- an incident rate ratio (IRR) of 1.93 in the least green and 1.43 in the most green. IRR is a measure of how much higher the rate of death is among the poorest, when compared with that among the richest.
The difference in IRR for circulatory disease was even larger -- 2.19 in the least green areas and 1.54 in the most green. The amount of green space had no effect on deaths caused by lung cancer or suicide.
"The implications of this study are clear: Environments that promote good health might be crucial in the fight to reduce health inequalities," Mitchell and colleagues concluded.
The study was published in this week's special issue of The Lancet, which focuses on social determinants of health.
"This study offers valuable evidence that green space does more than pretty up a neighborhood; it appears to have real effects on health inequality, of a kind that politicians and health authorities should take seriously," Dr. Terry Hartig, of the Institute for Housing and Urban Research at Uppsala University in Sweden, wrote in an accompanying comment on the study.
Another British study in the same issue of The Lancet found that best-practice interventions could eliminate most socioeconomic disparities in coronary heart disease deaths. Best practice interventions include: reduction of systolic blood pressure by 10mm/Hg, of cholesterol by 2mmol/L, and of blood glucose by 1mmol/L in pre-diabetic people; halving the presence of non-insulin dependent diabetes; and quitting smoking.
The researchers looked at 17,186 male civil servants, aged 40 to 69, and found that the 15-year risk of death due to coronary heart disease per 100 men was 11 for men with low-grade employment and 7.5 for men with high-grade employment. The researchers calculated that best-practice interventions would reduce overall coronary heart disease deaths by 57 percent and the difference in deaths between socioeconomic groups by 69 percent.
"Our results suggest that current best-practice interventions to reduce classic coronary risk factors, if successfully implemented in both high and low socioeconomic groups, could eliminate most of the socioeconomic differences in coronary heart disease mortality," concluded Professor Mika Kivimaki, of University College London, and colleagues.
Posted: November 2008