Low-carb, high-protein diet may cause atherosclerosis
MedWire News: Results from a mouse study indicate that consuming a low-carbohydrate, high-protein diet may cause atherosclerosis.
Diets that are low in carbohydrates, but high in protein have been widely recommended for optimum weight loss, as previously reported by MedWire News. They have also been reported to improve serum lipid levels.
However, Anthony Rosenzweig (Harvard Medical School, Boston, Massachusetts, USA) and team discovered that, “at least in animals, these diets could be having adverse cardiovascular effects that are not reflected in simple serum markers.”
The researchers fed mice a low carbohydrate, high protein diet (LCHP; 12% carbohydrate, 43% fat, 45% protein, and 0.15% cholesterol); a western diet (43% carbohydrate, 42% fat, 15% protein, and 0.15% cholesterol); or a standard chow diet (65% carbohydrate, 15% fat, 20% protein) for a period of 12 weeks.
As expected, mice who consumed the chow diet showed little sign of atherosclerosis. At 6 weeks mice consuming the LCHP diet had significantly more atheroma than mice on the western diet, at 5.4% versus 2.2%. This difference remained throughout the study, with corresponding values at 12 weeks of 15.3% versus 8.8%.
The mice consuming the LCHP diet had more aortic atherosclerosis and a reduced ability to generate new vessels in response to tissue ischemia than the other two groups of mice.
Interestingly, the changes were not explained by alterations in serum cholesterol levels, inflammatory markers, or oxidative stress, as might have been expected.
But, these mice had significantly reduced levels of endothelial progenitor cells (EPCs), which are involved in the promotion of vascular regeneration.
“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,” explained Rosenzweig. “This may be the mechanism behind the adverse vascular effects we found in mice that were fed the low-carb diets.”
He concluded: “Understanding the mechanisms responsible for these effects, as well as the potential restorative capacity that may counteract vascular disease, could ultimately help guide doctors in advising their patients.”
“This issue is particularly important given the growing epidemic of obesity and its adverse consequences.”
The results of this study are published in the Proceedings of the National Academy of Sciences.
MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a part of Springer Science+Business Media. © Current Medicine Group Ltd; 2009
By Helen Albert