Sodium chloride, more commonly known as salt, plays an integral role in our body’s fluid volume and electrolyte balance. Salt is also necessary to maintain the quality and safety of the food supply. Salt and sodium are often used interchangeably; however, salt is actually 40% sodium and 60% chloride.

Salt is associated with hypertension—yet there are a couple of different theories about how salt affects people’s bodies.The “salt hypothesis” proposes that higher levels of salt in the diet will lead to higher blood pressure, therefore increasing the risk of heart disease.¹ Other research proposes that the degree to which sodium impacts blood pressure may vary among individuals, with sodium reduction eliciting a large change in blood pressure among some individuals, and a lesser change in blood pressure among others.^2,3 People who are largely affected by the amount of sodium in the diet are commonly referred to as “salt sensitive.” However, salt sensitivity is not easily diagnosed. Therefore, the recommended intake for sodium addresses the general public and does not distinguish between those who are salt sensitive and those who are not.

Current Recommendations

According to the 2010 Dietary Guidelines, greater than 85% of Americans consume more than 2,300 mg of sodium per day. In fact, Americans today are eating an average of 3,400 mg of sodium a day. The new Guidelines maintains the 2005 recommendation that Americans should aim to consume less than 2,300 mg and further reducing intake to 1,500 mg among persons who are 51 and older and those of any age who are African American or have hypertension, diabetes, or chronic kidney disease.

The 2010 Dietary Guidelines for Americans Advisory Committee Draft emphasized that Americans are currently consuming too much sodium. The report recommended that in order to reduce the prevalence of hypertension, Americans must gradually, over time, reduce sodium intake from 2300 mg/day to no more than 1500 mg/day.

Impact of Other Nutrients

While decreasing sodium intake is the most common prescribed dietary change to control blood pressure, strong scientific evidence indicates that increasing the intake of other nutrients, including potassium, calcium, and magnesium, may counteract the effects of sodium on blood pressure levels for both salt-sensitive and non salt-sensitive individuals.^5-7

A significant portion of research has been done on potassium and other minerals and their effects on blood pressure. Increasing potassium has been shown to reduce blood pressure for individuals regardless of salt sensitivity and even when salt intake remains the same.8 In addition, a diet rich in calcium, magnesium and potassium is associated with lower blood pressure levels.⁶ By consuming adequate amounts of these minerals, blood pressure is lowered because the body expels additional sodium and therefore fluid.^9-11 Blood volume is decreased and less pressure is put on veins and arteries; therefore blood pressure is decreased. This effect also works the opposite way: when individuals do not consume enough potassium or calcium in their diets, the negative effect sodium has on their blood pressure is increased.⁸

On average, Americans currently consume only about half of the recommended level of 4,700 mg potassium/day and less than half of the recommended 1,000 mg calcium/day.^12,13 The 2010 Dietary Guidelines encourages people to choose foods that provide more potassium, such as fruits and vegetables, including potatoes, and low-fat or fat free dairy which is calcium-rich.

Sodium and the American Diet

The average American consumes nearly double the daily recommendations for sodium intake.¹² That’s about 4,600 mg of sodium each day—the primary sources of sodium in the diet include yeast breads, chicken and chicken-mixed dishes, and pizza, as illustrated in the chart below:¹⁴

Sodium in Frito-Lay Products

Frito-Lay products may not be as high in sodium as you may think. To put some sodium levels of foods commonly consumed into perspective, see the chart below:

* Information attained from the USDA Nutrient Database Release 22
** Current as of August 2010

References

1. Intersalt Cooperative Research Group. Intersalt study. An international co-operative study on the relation of blood pressure to electrolyte excretion in population. Design and methods. J Hypertension. 1986; 4:781-787.
2. Hollenberg NK. The influence of dietary sodium on blood pressure. J Am Coll Nutr. 2006; 25:240S-246S.
3. Franco V, Oparil S. Salt sensitivity, a determinant of blood pressure, cardiovascular disease, and survival. J Am Coll Nutr. 2006; 25:247S-255S
4. Cohen HW. American Journal of Medicine, Vol. 119, Issue 3, March 2006, Pages 275.e7-275.e14.
5. Morris RC Jr, Sebastian A, Forman A, Tanaka M, Schmidlin O. Normotensive salt sensitivity: Effects of race and dietary potassium. Hypertension. 1999;33:18-23.
6. Van Leer EM, Seidell JC, Kromhout. Dietary calcium, potassium, magnesium and blood pressure in the Netherlands. Int J Epidemiol. 1995;24:1117-1123
7. Institute of Medicine. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. Washington, DC: The National Academies Press; 2005.
8. Morris RC Jr, Sebastian A. Relationship and interactive between sodium and potassium. J Am Coll Nutr. 2006;35:262S-70S.
9. Haddy FJ, Pamnani MB. Role of dietary salt in hypertension. J Am Coll Nutr. 1995;14:428-438.
10. Whelton PK, He J, Cutler JA, Brancati FL, Appel LJ, Follmann D, Klag MJ. Effects of oral potassium on blood pressure: meta-analysis of randomized clinical trials. JAMA 1997;227:1624-1632.
11. Allender PS, Cutler JA, Follmann D, Cappuccio FP, Pryer J, Elliott P. Dietary calcium and blood pressure: a meta-analysis of randomized clinical trials. Ann Intern Med. 1996;124:824-829.
12. U.S. Department of Health and Human Services (DHHS). National Center for Health Statistics. Third National Health and Nutrition Examination Survey, 1988-1994. Hyattsville, MD: Centers for Disease Control and Prevention, 2001.
13. US Department of Agriculture. Agricultural Research Service. 2005-2006. What We Eat in America/National Health and Nutrition Examination Survey. http:/www.ars.usda.gov/Services/docs.htm?docid=13793
14. Sources of Sodium among the US Population, 2005-2006. Risk Factor Monitoring and Methods Branch Website. Applied Research Program. National Cancer Institute. http://riskfactor.cancer.gov/diet/foodsources/sodium. Updated January, 2010.