Low-carb diets have already been shown to bring about weight loss but the new trial suggests that they could also have an additional benefit for obese people by cutting heart disease risk through reducing inflammation.
Researchers from the Philadelphia Veterans Affairs Medical Center compared the effects of a low-carb diet with a traditional fat- and calorie-restricted diet among 78 extremely obese adults.
They measured both cholesterol levels and C-reactive protein, or CRP, a marker of inflammation in the blood.
Writing in the 15 September issue of the American Journal of Medicine (117, issue 6, pp398-405), they report that C-reactive protein levels decreased modestly in both diet groups overall. However, patients with a high-risk baseline level experienced a greater decrease in C-reactive protein levels on a low-carbohydrate diet, independent of weight loss.
And while both diet groups experienced similar decreases in the number of low-density lipoprotein particles (LDL) and increases in large high-density lipoprotein (HDL) concentrations, subjects on a low-carbohydrate diet experienced a greater decrease in large very low-density lipoprotein levels, which has been linked to the progression of artery disease.
But the authors also noted that those with lower to moderate CRP saw their levels go up on the low-carb plan. And the low-carb group also showed an increase in chylomicrons, particles that transport dietary fat from the gut to cells and tissue elsewhere in the body. This could be of 'potential concern', said the authors.
The study suggests that more research is needed to gauge the long-term impact of a low-carb diet on risk of cardiovascular disease.