Salt and Sodium; Petition to Revise the Regulatory Status of Salt and Establish Food Labeling Requirements Regarding Salt and Sodium; Public Hearing; Request for Comments

March 27, 2008 Division of Dockets Management (HFA-305) Food and Drug Administration 5630 Fishers Lane, Rm. 1061 Rockville, MD 20852 Re:Salt and Sodium; Petition to Revise the Regulatory Status of Salt and EstablishFood Labeling Requirements Regarding Salt and Sodium [Docket No. 2005P-0450] The American Medical Association (AMA) commends the Food and Drug Administration (FDA) for holding a public hearing on FDA?s policies regarding salt (sodium chloride) and sodium in food, and its willingness to reexamine this issue. This is especially important because of the relationship between salt intake and cardiovascular disease. The AMA is pleased to submit these comments as a follow-up to our oral testimony presented at the November 29, 2007 hearing. Sodium Intake and Cardiovascular Disease (CVD) Across populations, the progressive increase in blood pressure and the prevalence of hypertension with age are directly related to sodium intake. Numerous observational studies, randomized controlled trials, and meta analyses document that high sodium intake increases blood pressure.1-11 The public health focus usually has been on reducing hypertension, defined as systolic blood pressure (SBP) of 140 mm Hg or higher, diastolic blood pressure (DBP) of 90 mm Hg or higher, and/or use of antihypertensive medications. However, it is important to emphasize that the risks of developing cardiovascular disease increase as the blood pressure rises progressively over 115/75 mm Hg.12-14 This fact further reinforces the need to address risk factors that increase blood pressure, including sodium intake. The current average adult daily sodium intake in the United States approximates 4000 mg/2000 kcal.15 Secular trends show a 55 percent increase in sodium intake from the early 1970s to 2008; simultaneously, the age-adjusted prevalence of hypertension has increased by 50 percent.16 Excessive sodium intake has harmful cardiovascular effects independent of its effect on blood pressure. Sodium intake is an independent predictor of left ventricular mass.17-19 Additionally, platelet reactivity increases with high dietary sodium intake, and platelet function is linked to systemic sodium-potassium homeostasis.20 A lower-salt diet reduces aortic stiffness, independent of its effect on blood pressure, and studies show that salt intake is linked to arterial compliance.21,22 Excess sodium consumption increases calcium excretion and also increases caloric consumption by increasing fluid intake. In summary, the evidence is overwhelming that excessive sodium intake causes increased morbidity and mortality from cardiovascular disease.23-26 Recommended Sodium Intake. A sodium intake of less than 2400 mg/day has been a cornerstone of the National Heart, Lung, and Blood Institute?s National High Blood Pressure Education Program (NHBPEP) recommendations to prevent and manage hypertension since 1993.27 In 1998, the American Heart Association adopted a similar recommendation.28 In 2002, the United States Department of Health and Human Services established an objective for 2010 that at least 65 percent of the population should consume less than 2400 mg/day of sodium.29 Currently, only 20 percent of the population meets that objective. Results of the DASH-Sodium Trial showed that the most substantial reduction of systolic blood pressure occurred when sodium intake decreased from 2300 mg/day to 1500 mg/day.30 Furthermore, the virtual absence of either hypertension or a progressive rise in blood pressure with advancing age in populations with an average sodium ingestion of less than 1400 mg/day supports the concept of a threshold above which the risk of harmful cardiovascular disease consequences begins to increase.31 Sources of Dietary Sodium. In the typical U.S. diet, 77 percent of sodium comes from processed and restaurant foods, 12 percent occurs naturally in foods, 6 percent is added at the table, and 5 percent is added dur…