Orange juice counteracts the proinflammatory effects of a high-fat, high-carbohydrate meal, new research shows.

Drinking orange juice "could thus potentially prevent atherosclerosis — heart attacks and strokes — on the one hand and insulin resistance and diabetes on the other," lead author Dr. Paresh Dandona told Reuters Health by email.

"The high-fat, high-carbohydrate meal induces inflammation with an increase in endotoxin levels in blood and a parallel increase in the receptor for endotoxin," Dr. Dandona said. "In addition, it induces a protein, SOCS-3, which interferes with insulin action and contributes to insulin resistance. These changes are prevented when orange juice is taken with the meal."

In a March 3rd online publication in the American Journal of Clinical Nutrition, Dr. Dandona of the University of New York at Buffalo and colleagues report on their study of 3 groups of 10 normal healthy subjects.

All participants ate a 900 Kcal fast-food style high-fat, high-carbohydrate meal including egg and sausage muffins and hash browns. Each group also drank either water, a 300 Kcal glucose/water drink, or 300 Kcal of orange juice (about 3 cups).

The researchers obtained blood samples 1 hour before and up to 5 hours after the meal and drinks. The water and glucose groups had significant increases in markers of oxidative and inflammatory stress, expression of toll-like receptor 2 and 4, and concentrations of plasma endotoxin.

But the orange juice group had none of these changes — and furthermore, the orange juice drinkers had significantly less generation of reactive oxygen species by polymorphonuclear cells compared to the other groups.

"This potent effect of orange juice is probably attributable to its flavonoids," which suppress reactive oxygen metabolites in vitro, the authors say.

The researchers were surprised to find no increase in blood glucose levels at 60 minutes in the orange juice group, particularly because glucose levels were still elevated at that point in the other two groups.

"These data make the issue of macronutrient-induced postprandial inflammation a more complex one because, in our search for safe noninflammatory macronutrients, we have to consider safe combinations and those foods that buffer or neutralize the proinflammatory effects of other foods," the researchers add.

Am J Clin Nutr 2010.
David Douglas, March 19, 2010 • Reuters Health Information © 2010