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Ethnic Groups’ Genes Not to Blame For Diabetes
The theory that certain ethnic groups are genetically prone to diabetes is a myth, according to a new international study.
The study found no evidence to support the widely held “thrifty genotype theory”, which suggests that cycles of feast and famine early in human history created a gene that helps the body use scarce nutrients – a gene that leads to obesity and diabetes in comfortable, inactive modern lifestyles.
“Our study challenges the presumption that Native American, Mexican American, African American, Australian Aborigine, or other indigenous groups are genetically prone to diabetes,” said anthropologist Michael Montoya. “The evidence demonstrates that higher rates of diabetes across population groups can be explained by non-genetic factors alone.”
The study helps explain why more than 250 genes have been studied as possible causes of type-2 diabetes, but together these genes explain less than 1 percent of diabetes prevalence worldwide.
“When it comes to diabetes, we’re finding that genes are no more important for ethnic minorities than for anyone else,” said Stephanie Fullerton, a population geneticist at the US University of Washington.
Looking at the impact of social and environmental issues, the researchers noted that factors like poverty, housing segregation or poor diet were stronger indicators of diabetes than genes. “Our study shows that by focusing on genes, researchers miss the more significant and alterable environmental causes of diabetes,” Montoya said.
He added that future research efforts will require interdisciplinary teams that assess social, historical and environmental factors as carefully as researchers have studied the genetic factors.
“Poor diet, reduced physical activity, stress, low birth weight and other factors associated with poverty all contribute to the high rate of diabetes in these groups,” said epidemiologist Yin Paradies.
There are currently over 2 million diabetic people in the UK, and up to another 750,000 who have the condition and don’t know it yet. It’s also on the rise and increasing even in the very young. (Read more: Increase In Type 1 Diabetes In Under-Fives). About 1 in 7 of all deaths in the country are caused by diabetes – that’s about 33,000 deaths every year.
Montoya’s recent work has found that it’s virtually impossible for geneticists to define ethnicity and race in strictly scientific terms – historic, political and social factors inevitably influence their definition of genetic groups.
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