| "I'd rather give birth to an elephant." | | | | have urinary calcium excretion greater than 300 mg |
| That kind of imagery sticks in your mind. I know it stuck | | | | per day and at least two documented kidney stone |
| in mine. | | | | events. Then they divided the men into two equal |
| That was the description my colleague Pat used to | | | | groups. |
| convey the pain of a kidney stone, which I included in | | | | One group followed a traditional low-calcium diet, with |
| yesterday's e-alert when I told you how essential fatty | | | | only 400mg. of calcium intake each day. |
| acids can help prevent kidney stones. | | | | The other group followed a low-protein, low-salt diet, |
| Another new study reports that the | | | | with normal-to-high intake of calcium. Low protein was |
| kidney-stone-prevention diet that doctors have been | | | | defined as 15 percent of total calories, or about 90 |
| recommending for years doesn't work. That's the bad | | | | grams of protein for a 2,500 calorie diet. Sodium was |
| news. But the good news is, the same study reveals | | | | restricted to about 2000 mg. |
| what DOES work to reduce the urinary markers of | | | | Both groups were told to avoid foods rich in oxalate, |
| kidney stones and reduce your risk of recurrence. | | | | and to increase water intake to two liters a day in cold |
| Does a low calcium diet REALLY help prevent kidney | | | | weather and three liters a day in warm weather. Each |
| stones? | | | | man's urine was evaluated at baseline, one week after |
| First, a bit of background: there are several different | | | | randomization, and then once a year for five years (or |
| kinds of kidney stones, but 70 to 80 percent are | | | | until he had a recurrence.) |
| composed of calcium and oxalate (also called oxalic | | | | Dietary approach cut kidney stone recurrence rate in |
| acid). Oxalate is a type of salt found in certain foods, | | | | half. Over time, the low-protein, low-salt approach |
| like walnuts, spinach, rhubarb, parsley, and chocolate. | | | | produced dramatic results. In the low-calcium diet |
| Consequently, doctors have long advised kidney stone | | | | group, 23 of the 60 participants had a recurrence. But |
| sufferers to lower their calcium intake to help prevent | | | | in the low-protein group, only 12 of the 60 had another |
| recurrences. But long-term research failed to show a | | | | stone incident. That's HALF the recurrences, just from |
| benefit from this approach - and kidney stone | | | | a dietary change. |
| recurrence rates remained right around 50 percent. | | | | Ironically, the low-protein group showed as much |
| Some limited research had suggested that animal | | | | reduction in urinary calcium excretion as the |
| protein and salt intake might have more to do with | | | | low-calcium group - even though they consumed |
| kidney stones than calcium. So in this study, the | | | | normal to high levels of calcium. But the low-protein |
| researchers set out to compare the two dietary | | | | group also decreased its excretion of oxalate, the |
| approaches. | | | | other component of most kidney stones. In fact, in the |
| They recruited a group of 120 men with a history of | | | | low-calcium group, the oxalate excretion actually |
| calcium oxalate kidney stones; the participants had to | | | | INCREASED. |