Shrink rich-poor gap, save 1.5m lives, say researchers

The meta-analysis, published in the current issue of BMJ, was conducted by a team of researchers at the University of Yamanashi in Japan and the Harvard School of Public Health in the United States. The team analyzed 60 million subjects who took part in previous studies on the subject. They found that subjects who lived in areas with high income inequality are more likely to die younger, regardless of income, socioeconomic status, age or gender.

While the researchers say that their results must be interpreted with caution because of the heterogeneity of the studies analyzed, "the results suggest a modest adverse effect of income inequality on health, although the population impact might be larger if the association is truly causal." The researchers also state that there appears to be a threshold of income inequality beyond which adverse health effects begin to emerge. Even a modest connection between income inequality and health "can amount to a considerable population burden," they argue. The researchers also note that three-fourths of the countries belonging to the Organization for Economic Cooperation and Development (OECD) -- the group that includes most of the affluent industrialized world -- have experienced a growing gap between rich and poor over the past two decades.

In an accompanying editorial, Kate Pickett of the University of York and Richard G. Wilkinson of the University of Nottingham state that research of this type remains controversial because of the "deep political implications" of a causal relationship between income inequality between income inequality and overall health. Nonetheless, they note that the more than 200 studies performed since "the big idea" that distributing income more equally could improve the health of a society was first floated in BMJ in 1996 have confirmed the existence of this connection. "The benefits of greater equality tend to be largest among the poor but seem to extend to almost everyone," the editorial notes in its conclusion, which urges the political leaders of the developed world "to repair our 'broken society' by undoing the widening of inequalities that has taken place since the 1970s."

The full text of the research study and the editorial are available on the BMJ Web site.