The standard advice about the salt is so commonplace that you probably take it for granted -- eating too much salt causes high blood pressure. Years of scientific research have concluded that salt intake is strongly related to your blood pressure level. The Dietary Guidelines for Americans 2010, for example, simply says "on average, the higher an individual's sodium intake, the higher the individual's blood pressure," and that reducing sodium generally corresponds to lower blood pressure. The cause of diagnosable hypertension is an entirely differently matter. In many cases, there's no apparent cause for hypertension, according to MayoClinic.com.
Salt
Table salt contains about 2,300 mg of sodium in 1 tsp. Other salts may contain less sodium, but many common foods, such as snack items, processed goods, pizza and pork, have high levels of sodium. As a nutrient, sodium is an electrolyte that helps balance fluids in your body. Sodium is also involved in how your brain transmits signals to nerves and muscles. Adequate intake of sodium is defined as about 1,500 mg for most adults, according to the Institute of Medicine. The organization set 2,300 mg as the upper limit for daily sodium intake, and the dietary guidelines agree that this is appropriate for most healthy adults. However, many populations, such as black people, diabetics and those with multiple risk factors for heart disease, should aim for less than 1,500 mg. Athletes and certain people living in humid climates might have higher sodium needs.
Hypertension
Hypertension is abnormally high blood pressure. There are two kinds, essential and secondary. The Mayo Clinic says for most adults, there is no identifiable cause of essential hypertension. The roots of secondary hypertension generally lie in an accompanying healthy condition, such as kidney problems, medications to treat other problems and illegal drug use. The Centers for Disease Control and Prevention says 33 percent of American adults older than age 20 have hypertension. About 90 percent of all cases of hypertension are for essential hypertension. You are at risk of hypertension when your blood pressure goes over the normal 120/80 mmHg reading.
Sodium and Blood Pressure
In a review of the major clinical trials on salt intake and hypertension, Harvard's School of Public Health says most confirm that with increasing amounts of sodium in your diet, you could experience rises in blood pressure. Your blood pressure reading simply tells you how much work your heart has to do to move blood throughout your body, so your genes, family history of heart disease and your weight are also important factors related to your blood pressure. Age, race and diabetic status are also implicated. Harvard also says decreasing salt in your diet generally lowers blood pressure. According to the National Heart, Lung and Blood Institute, however, reducing dietary sodium produces one of the smallest effects on lowering blood pressure. Losing weight; eating healthier, such as consuming more fresh foods and reducing fat intake; and getting more exercise produce more significant drops in blood pressure. Eliminating alcohol can also help.
Get What You Need
The bottom line, according to the dietary guidelines, is that good nutrition requires you to give your body the nutrients it needs in the amounts you need. Most Americans eat too much salt. From age 2, the average American consumes 3,400 mg of sodium daily, about 47 percent higher than the upper limit recommendations. In helping to launch the National Salt Reduction Initiative, Dr. Bryan Becker, president of the National Kidney Foundation, summed up the link between salt and hypertension, saying, "Diets high in sodium increase blood pressure levels. ... Strategies that reduce salt intake for the masses can have the effect of lowering blood pressure, and that may be beneficial in easing the burden of chronic kidney disease in this country."
References
- Mayo Clinic; High Blood Pressure (Hypertension): Causes; March 22, 2011
- Harvard School of Public Health: Salt and Heart Disease: Key Studies
- FitDay: Myth or Fact: Salt Increases Blood Pressure
- University of Maryland Medical Center; Scientists Uncover How Excess Salt Leads to Hypertension; Feb. 16, 2004
- Institute of Medicine: Dietary Reference Intakes: Electrolytes and Water
- National Heart, Lung, and Blood Institute; Seventh Report of the Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure; December 2003
