Low-Carb Diet May Cut Heart Risks in Severely Obese

A low-carbohydrate diet can help severely obese people improve their cholesterol levels, and it may curb markers of inflammation better than a reduced-fat diet, preliminary research suggests.

In obesity, the body tends to be in a state of chronic inflammation, and this inflammation is believed to conspire with others factors — including high cholesterol — to promote the hardened, narrowed arteries that can lead to heart attack and stroke. Low-carb diets have been shown to cut excess pounds, but whether they reduce inflammation in the body has been unknown, according to the authors of the new study, led by Dr. Prakash Seshadri of the Philadelphia Veterans Affairs Medical Center. Theoretically, the high fat content in low-carb diets could raise levels of an inflammatory marker in the blood called C-reactive protein, or CRP. But when the researchers compared the effects of a low-carb diet with a traditional fat- and calorie-restricted diet among 78 extremely obese adults, they found that CRP levels typically fell to a greater degree with the carb-cutting diet. Specifically, men and women whose CRP levels were high to begin with showed a greater CRP drop on the low-carb diet than with the low-fat regimen — and most study participants did start out with high levels. However, those with lower to moderate CRP saw their levels go up on the low-carb plan. The significance of the findings is not fully clear, and they should be considered “exploratory,” Seshadri’s team reports in the American Journal of Medicine. Still, the low-carb diet showed some other advantages over its low-fat counterpart, according to the report. While both diets generally showed similar benefits for participants’ cholesterol levels, one type of “bad” cholesterol known as large very low-density lipoprotein (VLDL) declined to a greater degree with the low-carb diet. This subtype of LDL cholesterol is rich in blood fats called triglycerides, the researchers note, and studies have linked it to the progression of artery disease. In addition, the low-carb group lost more weight after six months — an average of 11 pounds more than those following a fat-conscious menu. The low-carb group ate about 43 percent of their calories from fat, compared with 33 percent in the reduced-fat group; but they also consumed fewer daily calories. The low-carb group did, however, show an increase in chylomicrons, tiny particles containing fat and cholesterol that are deposited in the blood during digestion. This finding, the authors note, “is of potential concern.” They say more research is needed to see how the metabolic effects in this study influence the long-term risk of cardiovascular disease. (SOURCE: American Journal of Medicine: Reuters Health News: October 2004.)