HTN: Dietary Sodium 2008
Click here to see the explanation of recommendation ratings (Strong, Fair, Weak, Consensus, Insufficient Evidence) and labels (Imperative or Conditional). To see more detail on the evidence from which the following recommendations were drawn, use the hyperlinks in the Supporting Evidence Section below.
HTN: Sodium Intake
Dietary sodium intake should be limited to no more than 2300 mg sodium (100 mmol) per day. Reduction of dietary sodium to recommended levels lowers systolic blood pressure by approximately 2 - 8 mmHg.
HTN: Sodium Intake Monitoring and Evaluation
If the patient demonstrates adherence to a 2300 mg sodium diet but has not achieved the treatment goal, then the dietitian should recommend the DASH dietary pattern and/or reduction in sodium to 1600 mg to further reduce blood pressure.
Risks/Harms of Implementing This Recommendation
Consideration should be given to individuals enagaging in high levels of physical activity, or in humid climates, resulting in excessive sweating due to the potential of hyponatremia.
Conditions of Application
For individuals who do not achieve the treatment goal, further dietary modification and collaboration with other members of the health care team may be necessary.
Potential Costs Associated with Application
For both Sodium Intake and Sodium Intake: Monitoring and Evaluation recommendations:
- Based on the JNC 7 report, dietary sodium should be reduced to no more than 100 mmol per day (2.4 g of sodium), resulting in an approximate systolic blood pressure reduction of 2 - 8 mmHg.
- Based on the JNC 7 report, a 1600 mg sodium DASH dietary pattern has blood pressure effects similar to single drug therapy in some individuals, and combinations of two or more lifestyle modifications can achieve even better results.
- Eleven studies report a positive association between increased sodium intake and hypertension; five of these studies also report a positive association between the sodium-potassium ratio and blood pressure (Cheung et al, 2000, Hu and Tian, 2001; Liu et al, 2001; Schroder et al, 2002; Geleijnse et al, 2003; He and MacGregor, 2003; Hajjar and Kotchen, 2003; Kwok et al, 2003; Geleijnse et al, 2004; Khaw et al, 2004; Zhao et al, 2004).
- Three randomized controlled trials and three meta-analyses report reductions in sodium intake ranging from 920 to 2, 300 mg per day (40 - 100 mmol per day) lowers systolic blood pressure by approximately two to six mm Hg and diastolic blood pressure by approximately two to three mm Hg (He et al, 2000; Appel et al, 2001; Espeland et al, 2002; Geleijnse et al, 2003; He and MacGregor, 2003; Geleijnse et al, 2004).
- A fourth randomized controlled trial reported maximal blood pressure lowering of 7.1 mm Hg systolic blood pressure in participants without hypertension, and 11.5 mm Hg systolic blood pressure in hypertensive subjects who followed a combination of the DASH dietary pattern and a sodium reduction to 1, 150 mg (Sacks et al, 2001).
- Two studies reported no significant differences in sodium intake between hypertensive and normotensive subjects, however, this may be more reflective of dietary changes occurring after diagnosis (Silaste et al, 2000; Lancaster et al, 2004).
Recommendation Strength Rationale
- Conclusion Statement is Grade I
- Updated from The Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Arch Intern Med 1997; 157:2413-46.
- Published in The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure. JAMA 2003;289:2560-71.
- Risks/Harms of Implementing This Recommendation
The recommendations were created from the evidence analysis on the following questions. To see detail of the evidence analysis, click the blue hyperlinks below (recommendations rated consensus will not have supporting evidence linked).
What is the relationship between sodium intake and blood pressure in healthy and hypertensive adults?
Appel LJ, Espeland MA, Easter L, Wilson AC, Folmar S, Lacy CR. Effects of reduced sodium intake on hypertension control in older individuals: results from the Trial of Nonpharmacologic Interventions in the Elderly (TONE). Arch Intern Med. 2001 Mar 12; 161 (5): 685-693.
Cheung BMY, Ho SPC, Cheung AHK, Lau CP. Diastolic blood pressure is related to urinary sodium excretion in hypertensive Chinese patients. Q J Med. 2000; 93: 163-168.
Espeland MA, Kumanyika S, Yunis C, Zheng B, Brown WM, Jackson S, Wilson AC, Bahnson J, Electrolyte intake and nonpharmacologic blood pressure control. Ann Epidemiol. 2002; 12: 587-595.
Geleijnse JM, Kok FJ, Grobbee DE. Blood pressure response to changes in sodium and potassium intake: a metaregression analysis of randomised trials. Journal of Human Hypertension, 2003; 17: 471-480.
Geleijnse JM, Kok FJ, Grobbee DE. Impact of dietary and lifestyle factors on the prevalence of hypertension in Western populations. Eur J Public Health. 2004; 14 (3): 235-239.
Hajjar I, Kotchen T. Regional variations of blood pressure in the United States are associated with regional variations in dietary intakes: The NHANES III Data. J Nutr. 2003; 133: 211-214.
He FJ, MacGregor GA. How far should salt intake be reduced? Hypertension, 2003; 42: 1,093-1,099.
He J, Whelton PK, Appel LJ, Charleston J, Klag MJ. Long-term effects of weight loss and dietary sodium reduction on incidence of hypertension. Hypertension, 2000; 35: 544-549.
Hu G, Tian H. A comparison of dietary and non-dietary factors of hypertension and normal blood pressure in a Chinese population. Journal of Human Hypertension, 2001; 15: 487-493.
Khaw KT, Bingham S, Welch A, Luben R, O'Brien E, Wareham N, Day N. Blood pressure and urinary sodium in men and women: the Norfolk Cohort of the European Prospective Investigation into Cancer (EPIC-Norfolk). Am J Clin Nutr. 2004; 80: 1,397-1,403.
Kwok TCY, Chan TYK, Woo J. Relationship of urinary sodium/potassium excretion and calcium intake to blood pressure and prevalence of hypertension among older Chinese vegetarians. European Journal of Clinical Nutrition, 2003; 57: 299-304.
Lancaster KJ, Smiciklas-Wright H, Weltzel LB, Mitchell DC, Friedman JM, Jensen GL. Hypertension-related dietary patterns of rural older adults. Preventive Medicine, 2004; 38: 812-818.
Liu L, Liu L, Ding Y, Huang Z, He B, Sun S, Zhao G, Zhang H, Miki T, Mizushima S, Ikeda K, Nara Y, Yamori Y. Ethnic and environmental differences in various markers of dietary intake and blood pressure among Chinese Han and three other minority peoples of China: results from the WHO Cardiovascular Diseases and Alimentary Comparison (CARDIAC) Study. Hypertens Res. 2001; 24 (3): 315-322.
Sacks FM, Svetkey LP, Vollmer WM, Appel LJ, Bray GA, Harsha D, Obarzanek E, Conlin PR, Miller III ER, Simons-Morton DG, Karanja N, Lin PH. Effects on blood pressure of reduced dietary sodium and the Dietary Approaches to Stop Hypertension (DASH) Diet. N Engl J Med. 2001; 344:3-10.
Schroder H, Schmelz E, Marrugat J. Relationship between diet and blood pressure in a representative Mediterranean population. Eur J Nutr. 2002; 41 (4): 161-167.
Silaste M-L, Junes R, Rantala AO, Kauma H, Lilja M, Savolainen MJ, Reunanen A, Kesaniemi YA. Dietary and other non-pharmacological treatments in patients with drug-treated hypertension and control subjects. Journal of Internal Medicine. 2000; 247: 318-324.
Zhao L, Stamler J, Yan LL, Zhou B, Wu Y, Liu K, Daviglus ML, Dennis BH, Elliott P, Ueshima H, Yang J, Zhu L, Guo D, for the INTERMAP Research Group. Blood pressure differences between northern and southern Chinese: role of dietary factors. The international study on macronutrients and blood pressure. Hypertension, 2004; 43 (6): 1,332-1,337.
References not graded in Academy of Nutrition and Dietetics Evidence Analysis Process
The Dietary Reference Intakes (DRI) and Recommended Dietary Allowances (RDA) are issued by the Food and Nutrition Board of the Institute of Medicine, National Academy of Sciences.
The Seventh Report of the Joint National Commitee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure, NIH Publication No. 04-5230, August 2004, produced by the National Heart, Lung and Blood Institute in cooperation with the National High Blood Pressure Education Program.
To access the pdf of the JNC-7, click here: