Senior author Anthony Rosenzweig, M.D. says, “It’s very difficult to know in clinical studies how diets affect vascular health. We, therefore, tend to rely to on easily measured serum markers such as cholesterol, which have been surprisingly reassuring in individuals on low-carbohydrate/high-protein diets, who do not typically lose weight. But our research suggests that, at least in animals, these diets could be having adverse cardiovascular effects that are not reflected in simple serum markers.”
The research team found that the plaque buildup and impaired ability to form new vessels were associated with a reduction in vascular progenitor cells, which some believe could play a protective role in maintaining vascular health. Rosenzweig adds, “A causal role for these cells has not yet been proven, but this new data is consistent with the idea that injurious stimuli may be counterbalanced by the body’s restorative capacity. This may be the mechanism behind the adverse vascular effects we found in mice that were fed the low-carb diets.”
The scientists observed mice fed a low-carb/high-protein diet at six weeks, and again at twelve weeks. Consistent with human studies, the mice fed the low-carb diet gained 28 percent less weight than the mice fed a “Western diet”. However, further examination revealed that mice blood pressure exhibited a larger degree of atherosclerosis, as measured by plaque accumulation: 15 percent compared with nearly 9 percent.
The researchers believe that the findings point out that there can be inconsistencies between weight loss or serum markers and vascular health, and that vascular health can be affected by macronutrients other than fat and cholesterol - in this case, protein and carbohydrates. Rosenzweig concludes, “This issue is particularly important given the growing epidemic of obesity and its adverse consequences. For now, it appears that a moderated and balanced diet, coupled with regular exercises, is probably best for most people.”