There has been quite a shake-up in salt and sodium recommendations due to a report from the Institute of Medicine of the National Academy of Sciences. The report states that current sodium recommendations are too low for most people and can even cause health problems. The institute’s report clashes with its own 2005 report and with the Dietary Guidelines for Americans, the American Heart Association and many others who have put years of effort into getting Americans to consume less sodium.
As we have explained before, sodium is an essential nutrient with the potential to be under- or over-consumed. The challenge is to know the limits. The Institute of Medicine report explains that establishing these cutoffs based on good science is difficult.
QUESTION: How do U.S. public health sodium recommendations compare with the amount of sodium people typically consume?
ANSWER: Humans from all cultures and geographic areas tend to consume about 3,500 milligrams of sodium daily, equal to about 1-1/2 teaspoons of salt. In 2005 the institute recommended that most Americans consume less than 2,300 milligrams daily — less than a teaspoon of salt. Its 2005 report also indicated that millions of individuals over age 50, of African-American descent and those with high blood pressure, diabetes or chronic kidney disease reduce daily sodium intake further, to 1,500 milligrams.
Q: What health problems can be worsened by low sodium intake?
A: Although the Institute of Medicine found evidence that excessive sodium intake can increase the risk for cardiovascular disease, it indicated that present-day research does not support consumption of less than 2,300 milligrams a day.
In fact, the current report states, among people with diabetes, chronic kidney disease or pre-existing cardiovascular disease who followed that restriction, there was no benefit and some evidence of harm — and people with congestive heart failure were at greater risk.
Consuming inadequate amounts of sodium also has been related to conditions such as an increase in
insulin resistance (possibly step one in the development of diabetes and metabolic syndrome) and an increase in blood triglycerides (linked with heart disease).
Q: What should the average person do?
A: Although there are medical conditions that can require a lower- or low-sodium intake, most of us can likely benefit from consuming a wide variety of wholesome foods along with a moderate amount of salt in our diets. Consuming a wide variety of foods increases potassium in the diet, which is likely as important as avoiding excessive dietary sodium.
Interestingly, humans have what is called a specific appetite for sodium, so that those who do not get enough might consciously or unconsciously choose foods higher in sodium.
Of course, always consult your doctor or other health professional before making drastic changes to your diet.
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Alan Titchenal, Ph.D., C.N.S., and Joannie Dobbs, Ph.D., C.N.S., are nutritionists in the Department of Human Nutrition, Food and Animal Sciences, College of Tropical Agriculture and Human Resources, University of Hawaii at Manoa. Dobbs also works with University Health Services.