There’s a lot of disagreement among experts about whether too much sodium results in hypertension. A more pernicious problem from eating too much salt may be kidney stones and osteoporosis. In a new study, researchers say that a high sodium diet can lead to the latter because salt depletes the body of calcium.
Sodium hypertension dispute
That a high sodium diet may ultimately lead to hypertension was accepted as fact for decades. But recently, researchers have questioned whether drastically cutting down on sodium is safe for everyone. Studies have revealed some unintended consequences of low sodium diets in some people, including high LDL (bad) cholesterol, higher fasting insulin levels and ironically, hypertension.
Reducing salt intake to keep your blood pressure in check remains controversial. A high-sodium diet has been more strongly associated with kidney stones and osteoporosis. For years the scientific community has tried to find out exactly why people who eat a lot of salt are prone to those medical problems.
How sodium depletes calcium
Researchers at the University of Alberta say they now know why salt increases the risk for kidney stones and osteoporosis: when the body sloughs off excess sodium, it takes calcium along with it.
Using animal models, lead researcher Todd Alexander and his team discovered that the body regulates sodium and calcium with the same molecule. When sodium intake is higher than the body can handle, the excess is flushed in the urine. The molecule doesn’t discriminate and calcium goes along for the ride. High levels of calcium in the urine can lead to kidney stones, while depleted levels of calcium in the body lead to osteoporosis.
A parallel to rising salt intake
The impact of this sodium/calcium-regulating molecule can be seen in the real world. Kidney stones are on the rise and urologists say more adults are developing kidney stones in their 20s and 30s instead of their 40s and 50s. Rates are rising faster in women. Kidney stones in children, once rare, are also becoming more common.
According to estimates from the National Osteoporosis Foundation, 10 million people in the U.S. have the condition and 34 million are at risk for developing osteoporosis. Even though osteoporosis is normally associated with post-menopausal women, more than one quarter of those at risk are men.
Use common sense
Although the link between high sodium in the Western diet and rising kidney stone and osteoporosis rates isn’t supported by science in a particular study yet, the findings of the University of Alberta researchers suggests that such a study is warranted.
Meantime, you’re free to draw your own conclusions and even if you have no hypertension issues, cutting down on salt seems to make a lot of sense. The best way to lower your sodium intake is to avoid processed foods and limit restaurant meals. Do your own cooking with fresh ingredients and rely on spices, not salt, to enhance flavor.
Source: Science Daily, New York Times, Better Bones, Beliefnet