Diversity may be killing older African-Americans and Hispanics, according to a new peer-reviewed study published in the America Journal of Public Health, which shows that people suffer less cancer and heart disease when they live among their racial or ethnic peers.

“Living in an ethnically dense neighborhood is beneficial when it comes to heart disease and cancer,” said Kimberly Alvarez, a co-author of the new study, which was funded by the National Institutes of Health.

Alvarez’s phrase, “ethnically dense,” describes a community in which at least 50 percent of people are from the same ethnic group.

Many progressive groups advocate the use of government to increase diversity in housing, education, health care and other sectors.

Alvarez’s study reviewed the health records of 2,367 Mexican-Americans and 2,790 African-Americans older than 65, and concluded they lived longer if they inhabited a community mostly populated by their group.

African-Americans “living in a county with an ethnic density of 50% or more … were 46% less likely to report doctor-diagnosed heart disease and 77% less likely to report cancer than those who lived in an ethnic density of less than 25%,” said a summary of the report, authored by Columbia University’s Mailman School of Public Health. (RELATED: Living in an Ethnically Homogenous Neighborhood Boosts Health of U.S. Minority Seniors)

The Mexican-Americans in the study “were 33% and 62% less likely to report heart disease and cancer, respectively,” when more than half of their neighbors were similar to them ethnically.

The reduced death rate in “ethnically dense” neighborhoods may occur because similar neighbors are “likely to share values like respect for elders and have close-knit family structures,” said Becca Levy, a study co-author and an associate professor of Epidemiology and Psychology at the Yale School of Public Health.

Earlier studies showed high levels of social support within communities of Hispanic immigrants, said Alvarez, and “these networks may facilitate better health behaviors and, in turn, better health outcomes.”

“That strikes me as likely, but probably not the whole explanation,” said Peter Wood, author of the 2003 book, “Diversity; The Invention of a Concept.”

“One aspect that the study does not examine — but which I think would bear further research — is the degree to which these positive health outcomes are effected by lower levels of stress and higher level levels of emotional support,” said Wood, who is now the president of the National Association of Scholars.

Progressives’ political demands for enforced and subsidized variety have precipitated numerous controversies. For example, the federal government has forced local governments to build neighborhood housing for groups of people — such as Hispanics or Africans-Americans — that Washington believes are “under-represented” in the community.

Diane Johnson, the New Jersey director of the Department of Housing and Urban Development, told an interviewer with NJToday that “different people are living in different communities and people have to understand and learn to live with the other people.” Her agency, she said in April 2012, “is the enforcer.”

The Columbia study provided political ammunition to the Wood and other critics of government-imposed variety.

They argue it undermines local flexibility and civil society, which is voluntary cooperation via neighborhoods, marriage, sports leagues, churches and nonprofits.

“People ought to be able to live where they want, but … policies that intend to fragment ethnic communities and disperse people through a wide population, might have unintended but deleterious effect on the people you are trying to help,” Wood said.

This criticism was bolstered by a large 2006 Harvard study that showed people enjoyed a lower quality of life in a “diverse” neighborhood.

“The effect of diversity is worse than had been imagined,” said author Robert Putnam, who had previously championed government-imposed variety. “It’s not just that we don’t trust people who are not like us … we don’t trust people who do look like us” within diverse communities.

People in diverse neighborhoods “don’t trust the local mayor, they don’t trust the local paper, they don’t trust other people and they don’t trust institutions. … The only thing there’s more of is protest marches and TV watching,” he said

The new health studies focused on African-Americans living in New Haven, Conn., and north-central North Carolina; and Mexican-Americans in Arizona, California, Colorado, New Mexico and Texas.

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