Robert H. Eckel, MD, director of the general clinical research center at the University of Colorado Health Sciences Center, Denver and the chairman of the American Heart Association's Nutrition, Physical Activity, and Metabolism Council has stated that "our worries over the Atkins diet go way past the question of whether it is effective for losing weight or even for keeping weight off. We worry that the diet promotes heart disease. We have concerns over whether this is a healthy diet for preventing heart disease, stroke, and cancer. There is also potential loss of bone, and the potential for people with liver and kidney problems to have trouble with the high amounts of protein in these diets."
Over the years, even in light of numerous studies demonstrating low-carb diets are effective for weight loss, improving HDL and triglycerides, improving insulin sensitivity and glycemic control and even sparing lean body mass, Dr. Eckel has maintained his position that low-carb diets are not healthy.
Now human data, published in the journal Osteporosis International, highlights (once again) the superiority of low-carb diets for weight loss while also providing concrete evidence that the diet does not lead to bone loss. The study's lead author, Dr. John D. Carter, an assistant professor at the University of South Florida College of Medicine, was surprised since "people on low carbohydrate diets absorb less calcium through the gut and excrete more calcium in the urine, so you'd expect they would be leaching their bones." However tests conducted on those following a low-carb diet found there was "no significant change in the bone turnover ratio."
I'm not surprised by the findings since the warning that high protein intake will leech calcium from bones was based on a hypothesized "potential" taken together with animal model data rather than hard data from human studies. In fact, we've had the data for quite some time that shows higher consumption of protein may actually be beneficial to bone health!
Just last year a study published in the American Journal of Clinical Nutrition examined the relationship between protein consumption and bone health in 1,000 women averaging 75 years in age. Higher protein intakes were associated with improvements in the bone density in the hip, and the quality of the bone in the heel.
The researchers in this latest study concluded "Although the patients on the low-carbohydrate diet did lose significantly more weight than the controls did, the diet did not increase bone turnover markers compared with controls at any time point. Further, there was no significant change in the bone turnover ratio compared with controls." I wonder what Dr. Eckles has to say now?