Diet doesn’t lower risk of Type 2 in black children

More fruits and veggies lower insulin resistance

Regardless of dietary patterns, African-American children are at higher risk of developing Type 2 diabetes than white children.

Those findings from the University of Alabama in Birmingham and the University of Southern California in Los Angeles published in the March issue of the American Journal of Clinical Nutrition served as a "myth buster" for researchers.

Researchers refuted a long-standing theory that the higher risk among African-American children is associated with high carbohydrate and fat consumption which leads to obesity.

"Without exception, every child I see with Type 2 diabetes, regardless of racial group, is obese," says Lori Laffel, MD, MPH, director of pediatrics at Joslin Diabetes Center in Boston. "While we all know diet contributes to insulin resistance, clearly there is something else at work here, probably something genetic."

"No one doubts a predisposition to Type 2 diabetes exists in African-Americans, and we’ve found out at least one thing that doesn’t cause the increased risk. So the multimillion dollar question is what does cause the differences?" says Barbara Gower, PhD, assistant professor of medicine at the University of Alabama and an author of the dietary study.

Of 54 white children and 41 black children selected from an ongoing study of childhood obesity in the Birmingham area, Gower says her team was surprised to find that the African-American kids reported they ate twice as much in fruit, 25% more vegetables, but 40% less dairy products than the whites. However, the African-American group had a higher consumption of calories and fat than the whites. Subjects were asked to recall their food consumption over a two-week period.

Dietary factors do have a role

Researchers also found that black children from high socioeconomic classes had less risk of high cholesterol than white children, a result which lends credibility back to dietary factors having some role, says Gower. Across the board, children in higher socioeconomic classes were less at risk for diabetes than their poorer peers.

Gower and colleagues at the University of Southern California also found black children had significantly lower insulin sensitivity and nearly three times higher acute insulin response values. "It almost has to be genetic," she says, "but I am also looking at the possibility that gestational diabetes in the mothers may be a factor, since so many African-American women have it and so many are prone to obesity. We just don’t know what that aspect of the insulin and glucose mechanisms means to the fetus later in life. It’s something we should look into."

Blacks are at a greater risk of diabetes

These results present some alert flags in clinical practice, says Gower. "Clinicians need to be aware that African-Americans are different at any level of obesity and they are at a greater risk of diabetes."

Even though the mechanism isn’t entirely understood, she says, "It is more important than ever to encourage a healthy lifestyle in these groups. While diet and physical activity levels don’t explain the increased risk, they still help. Weight loss always helps decrease risk."

Laffel adds, "It’s not that diet doesn’t count, not at all. The main point here is to recognize the difference in insulin sensitivity and insulin secretion association with the African-American population.

Laffel says she "can’t stress enough" the importance of clinicians bringing home the weight control message to young patients. "If they go on to develop Type 2 diabetes, the risk of complications is extraordinary.

[Contact Lori Laffel at (617) 732-2603 and Barbara Gower at (205) 934-4087.]