|Peeing Your Bones Down the Toilet
A 2003 review of the safety of low carbohydrate diets reeled off an alarming list of potential problems: "Complications such as heart arrhythmias, cardiac contractile function impairment, sudden death, osteoporosis, kidney damage, increased cancer risk, impairment of physical activity and lipid [cholesterol] abnormalities can all be linked to long-term restriction of carbohydrates in the diet."
There is a particular concern that children who go on the Atkins Diet might suffer permanent physical and mental damage as a result of starving their bodies of critical nutrients. As one U.S. child nutrition specialist explained, "The effect can be to dull the mind, stunt growth, and soften bones...I wouldn't want to risk it by putting my child on a low carbohydrate diet."
The concern with bone health arises from the fact that muscle protein has a high sulphur content. When people eat too much of this meat protein, sulfuric acid forms within our bodies which must somehow be neutralized to maintain proper internal pH balance. One way our bodies can buffer the sulphuric acid load caused by meat is with calcium borrowed from our bones. Cheese is also a leading source of these sulphur-containing proteins. People on high meat diets can lose so much calcium in the urine that it can actually solidify into kidney stones. Over time, high animal protein intakes may leach enough calcium from the bones to increase one's risk of osteoporosis. People may be peeing their bones into the toilet along with the ketones.
The Harvard Nurse's Health Study, which followed over 85,000 nurses for a dozen years, found that those who ate more animal protein had a significantly increased risk of forearm fracture. While plant-based proteins did not show a deleterious effect, women eating just a serving of red meat a day seemed to have significantly increased fracture risk. Other studies have linked meat consumption to hip fracture risk as well.
Although Atkins conceded, "kidney stones are a conceivable complication," Atkins dismissed any assertion that his diet might endanger bone health. Researchers decided to test his claim directly.
In 2002, researchers from the Universities of Chicago and Texas published a study that put people on the Atkins Diet and measured 1) how acidic their urine got and 2) just how much calcium they were losing in their urine. They reported that the Atkins Diet resulted in a "striking increase in net acid excretion." After just two weeks on the Atkins Diet, the subjects were already losing 258mg of calcium in their urine every day. They concluded that the Atkins Diet "provides an exaggerated acid load, increasing risks for renal calculi [kidney stone] formation and bone loss." In addition, the Atkins Diet is actually deficient in calcium in the first place--even if one includes his recommended 65 supplements. Luckily there's a 66th, available on his website.