Most of the pre-prepared foods available at department stores and fast food take-aways have high salt content. We know that high salt content in food is associated with a number of risk factors for health such as hypertension, heart diseases and stroke. New research from University of Alberta in Canada now points that high levels in salt in your food also leaches calcium out of your body and in the long run could be leading you towards osteoporosis if you are not careful about your diet. (1)
Researchers at the University of Alberta found that when sodium was being excreted by the body after being filtered out through the kidney, it was also taking calcium along with it. The team of researchers lead by Dr. Todd Alexander worked on animal models and cells to find that it was no coincidence that those who ate high-salt diets were also the people who more often than not the ones who developed kidney stones and poor bone health as they aged.
Dr. Alexander and his team discovered that there exists a link between sodium and calcium and that it is of a shared molecule. A common molecule regulates the absorption of both sodium as well as calcium in our body. So, when we take in too much salt through our diets than our body really needs, our body gets rid of the excess sodium through the urine but it also takes calcium along with it thus depleting stocks of calcium over time in our body making us susceptible to fractures. Besides this, higher levels of calcium in urine also cause kidney stones to develop.
As per Dr. Alexander, “When the body tries to get rid of sodium via the urine, our findings suggest the body also gets rid of calcium at the same time. This is significant because we are eating more and more sodium in our diets, which means our bodies are getting rid of more and more calcium. Our findings reinforce why it is important to have a low-sodium diet and why it is important to have lower sodium levels in processed foods.” (2)
The facet that is new to the research is the dual role of the molecule. It was not known earlier that molecule responsible for sodium absorption also regulates the levels of calcium in the body.
According to Dr. Alexander, “We found a molecule that seems to have two jobs – regulating the levels of both calcium and sodium in the body. Our findings provide very real biological evidence that this relationship between sodium and calcium is real and linked.” (2)
A journal editorial written about this research discovery noted the molecule could be a drug target to one day ‘treat kidney stones and osteoporosis.’
The research was funded by National Director of Research of The Kidney Foundation of Canada and gains particular significance today as more families chose pre-prepared foods and take-aways to reduce their work burden at home after a gruelling day at office and thus compromise on their health in the long run. Current data of the US reveals that as many as 10% of adults will have kidney stones once in their life and this prevalence is on the rise. However, there may be other factors besides salt content in diets such as high rates of obesity and diabetes which may be contributing to this rise.
It is understood that the average Canadian consumes more than double the recommended daily intake of salt for the ages 9 and 50 years which stands at 1500 mg. (3)
Some foods that could contain high salt content are: pizza, ham, cheese, bacon, ham, pickles, stock cubes, smoked meat, roasted nuts, salami, pasta sauce, ready meals, burgers, soups, sausages, mayonnaise, ketchup etc.
- Diets High in Salt Could Deplete Calcium in the Body; Science Daily News; Web August 2012.
- Diets high in salt could deplete calcium in the body: UAlberta Research; Faculty of Medicine & Dentistry – University of Alberta;
Web August 2012.
- High-salt diets linked to calcium loss; The Globe And Mail; Web August 2012.
Abstract of the technical report of this study may be accessed at:
- The epithelial sodium/proton exchanger, NHE3, is necessary for renal and intestinal calcium (re)absorption; American Journal of
Physiology – Renal Physiology; Web August 2012.