Up until this point, I’ve been explaining the importance of the major minerals for our health and making it known that most people don’t get enough of these minerals. Now it is time to shift gears and take a look at two minerals that have been completely abused by the food and beverage industry.  Yes, they are just as important as the other minerals we’ve already gone through, but too much of a good thing can turn ugly. Remember, life is all about balance.

Phosphorus in the body is mostly found in the skeleton. The kidneys and parathyroid hormone are the primary regulators of the concentration of phosphorus in the blood. That is important because phosphorus plays a key role in the regulation of the body’s acid/base balance, mineralization of the bones and teeth, the structure of cell membranes, absorption and transport of nutrients, regulation of enzyme activities responsible for the body’s metabolic reactions, conversion of glucose to energy and the structure of DNA and RNA.

Because phosphorus in foods is often found bound to protein, protein-rich foods such as poultry, fish and meat are the best sources, at approximately 15 mg of phosphorus per gram of protein.  Nuts, legumes, cereals, grains, chocolate, coffee and tea contain phosphorus in the form of phytic acid. However, phytic acid binds positively charged ions such as calcium, zinc and iron making those minerals, as well as the phosphorus, less available for absorption from foods.

Soft drinks and sodas are another dietary source of phosphorus, with Hawaiian Punch being among the highest soft drink source! Other unhealthy foods that have a bright side when it comes to phosphorus are processed foods. For example, one ounce of cheese spread contains approximately 257 mg of phosphorus compared with one ounce of naturally aged cheddar that contains 145 mg.¹ This information does not mean you should increase your consumption of processed foods and soft drinks though. In fact, quite the opposite—most people are getting too much phosphorus.

The FDA recommended Daily Value for phosphorus is 1000mg/day for adults.² The over-consumption of sodas and processed foods with excessive levels of phosphorus is causing health problems. One study links the consumption of colas with chronic kidney disease due to their high phosphorus content.³

Everyone should consciously reduce their intake of phosphorus from sodas and processed foods.  This is especially important for those with chronic kidney disease and risk factors for cardiovascular disease.⁴ There is only a small portion of the population at risk for a phosphorus deficiency—those with hyperparathyroidism, absorption-related diseases and those who regularly consume large amounts of antacids or alcohol. Vitamin D enhances absorption of phosphorus, and when a vitamin D deficiency and low blood phosphorus are combined, the result is muscular weakness associated with rickets.⁵ One study found that people with a phosphorus deficiency also have low bone mineral density, which is associated with osteoporosis and osteopenia.⁶

Another mineral that most people get too much of is sodium. Sodium is found naturally in milk, meat, eggs and vegetables. Sodium is completely absorbed by the small intestines, and its functions in the body involve glucose absorption into nerve and muscle cells and water balance inside and outside cells. It is one of three principal electrolytes.

The adequate intake for adults between 19 and 50 years old is 1,500 mg/day. For older adults it is less with 1,300mg/day for 51-70 years and 1,200 for 71 years plus. Unfortunately, the average American intake is much greater, at 3,100-4,700 mg/day for men and 2,300-3,100 mg/day for women.^4,7 The health problems for those with a diet high in sodium are numerous and severe. Most people know that eating salty foods can lead to hypertension⁸, but few realize that it also may lead to cardiovascular disease, gastric cancer and other cancers⁹, ulcers caused by H. pylori bacteria, obesity, fluid retention, Meniere’s disease (inner ear condition affecting hearing and balance), worsening of renal disease, renal calculi, asthma attack triggers and osteoporosis.

The good news is that studies show decreasing sodium intake greatly reduces this risk. There is a better way than trying to use the right amount of salt to get 1,500 mg of sodium daily (about 2 teaspoons). Most restaurant, packaged and pre-prepared foods and drinks contain sodium. So even with a fairly healthy diet, most of us get more than enough sodium already from the occasional dinner out, store-bought meal and packaged snack. To combat this, leave the salt out when cooking meals. Also buy salt-free or low-sodium snacks when possible. It is only if you are an athlete doing high-intensity exercise in hot weather conditions with excessive fluid and electrolyte loss that sodium must be replaced in the body to replenish fluid balance. In that case, coconut water is the best natural electrolyte drink.

References

¹ Noori N, Sims JJ, Kopple JD, Shah A, Colman S, Shinaberger CS, Bross R, Mehrotra R, Kovesdy CP, Kalantar-Zadeh K. Organic and inorganic dietary phosphorus and its management in chronic kidney disease. Iran Journal of Kidney Disease. 2010 Apr; 4(2):89-100.

² Food and Drug Aministration. XIV. Appendix F: Calculate the percent daily value for the appropriate nutrients. In: Food Labeling Guide. College Park, MD: Center For Food Safety and Applied Nutrition, 2008.

³ Saldana TM, Basso O, Darden R, Sandler DP. Carbonated beverages and chronic kidney disease. Epidemiology. 2007 Jul; 18(4):501-6.

⁴ Lichtenstein AH, Appel LJ, Brands M, Carnethon M, Daniels S, Franch HA, Franklin B, Kris-Etherton P, Harris WS, Howard B, Karanja N, Lefevre M, Rudel L, Sacks F, Van Horn L, Winston M, Wylie-Rosett J. Diet and lifestyle recommendations revision 2006: a scientific statement from the American Heart Association Nutrition Committee. Circulation. 2006 Jul 4;114(1):82-96.

⁵ Sahay M, Sahay RK. Refractory rickets in the tropics. Journal of Pediatric Endocrinolgy Metabolism. 2010 Jun; 23(6):597-601.

⁶ Multani SK, Sarathi V, Shivane V, Bandgar TR, Menon PS, Shah NS. Study of bone mineral density in resident doctors working at a teaching hospital. J Postgrad Med. 2010 Apr-Jun;56(2):65-70.

⁷ Centers for Disease Control and Prevention (CDC). Sodium intake among adults – United States, 2005-2006. Morb Mortal Wkly Rep. 2010 Jun 25; 59(24):746-9.

⁸ Erwteman TM, Nagelkerke N, Lubsen J, Koster M, Dunning AJ. Beta blockade, diuretics, and salt restriction for the management of mild hypertension: a randomised double blind trial. Br Med Journal. 1984 Aug 18; 289(6442):406-9.

⁹ Strnad M. Salt and cancer. Acta Med Croatica. 2010 May; 64(2):159-61.

¹⁰ Ball D, Maughan RJ. The effect of sodium citrate ingestion on the metabolic response to intense exercise following diet manipulation in man. Experimental Physiology. 1997 Nov; 82(6):1041-56.