Dietary Sodium and Blood Pressure in Older Adults

Abstract

Given the proportion of older adults who are hypertensive and the population of older adults who are at risk for hypertension, the U.S. must mobilize public health efforts aimed at prevention. Scientific evidence has demonstrated the efficacy of sodium reduction to lower blood pressure. Translating this evidence into practice involves knowledge about the food sources of sodium so effective interventions can be designed and implemented. The purpose of this essay was to examine major food group sources of sodium in a cohort of older adults, with and without high blood pressure, in an urban community in Southwestern Pennsylvania. The University of Pittsburgh's "Center for Healthy Aging" promotes healthy aging in the community with the "10 Keys to Healthy Aging" campaign. One of the keys aims to lower systolic blood pressure to ≤140 mmHg. A low sodium intervention was implemented by the CHA project in hypertensive individuals. The sodium intake of the 521 community volunteers, mean age 74.5 years, 60% male, 94.1% white, who completed a FFQ, was compared to a sub-sample of hypertensives (n=214) who, in addition, collected one 24-hour urinary sodium. Mean baseline dietary sodium for the entire cohort was 1,796 mg per day compared to 1,821 mg per day in hypertensives. Urinary sodium was 1.8 times higher (141 mmol/24 hrs [3,240 mg]) than self-reported intake and decreased to 130 mmol/24 hrs (2,990 mg) at 6-months. The correlation between dietary and urinary sodium at baseline was weak (r=0.16) and remained weak (0.23) at 6-months. Major food sources of sodium were soups, breads, tomato sauce, salad dressings, and prepared cereals. Data indicate that the sodium intake of the group exceeds the 2005 Dietary Guidelines of ≤1500 mg per day by approximately 200% for individuals at increased risk using urinary sodium values. Even the most successful dietary interventions to reduce sodium intake to the recommended levels would be ineffective without the food industry’s help in reducing sodium added to foods during processing. This prevention strategy, in combination with stronger public health messages, would help to reduce the sodium intake in the population and help to achieve reductions in blood pressures.