Dietary sodium intake correlates with systolic and diastolic blood pressure and risk for cardiovascular morbidity and mortality.
Reduced dietary sodium can lower blood pressure, increases sympathetic nerve activity, decreases insulin sensitivity, activates renin angiotensin system, and stimulates aldosterone secretion(Graundal NA, Aldeman MH).
Reductions in sodium intake have been associated with lower rates of hypertension, myocardial infarction, stroke, and cardiovascular mortality.
Increased dietary sodium is associated with high blood pressure.
The International Study of sodium, potassium, and blood pressure study and enrolled more than 10,000 patients and showed that salt intake and blood pressure are directly correlated.
Randomized controlled trials comparing different sodium intake involved patients with CHF: 1840 mg/d vs 2760 mg/d revealed decreased sodium intake associated with increased mortality and hospitalization (Cohen HW).
A meta-analysis of 28 randomized controlled trials of salt reduction and blood pressure changes show that salt reduction led to roughly 25% reduction in stokes in cardiovascular mortality.
An increase in dietary sodium intake is linked to increased all-cause and cardiovascular mortality.
Sodium intake suppresses renin, which in turn results in the reduction of angiotensinII and aldosterone production, yielding a net vasodilatory effect and natriuretic effect: preventing excessive blood pressure.
It is postulated that insult, sensitive individuals the reading, angiotensin aldosterone system develops a higher setpoint at which it is suppressed,so that a height intake in these patients result in the net increase in plasma volume and peripheral vascular resistance raising blood pressure.
Severe sodium restriction may be harmful in patients with CHF (Jessup M).
Relationship between sodium consumption and clinical outcomes is variable.
More than three quarters of sodium in the United States diet is added during food processing.
In most developed countries, 80% of consumed salt comes from industry-prepared food, 5% come from natural salt, 15% comes from salt added during cooking or eating.
Dietary sodium intake averages approximately 3400 mg per day in US adults.
Sodium dietary guidelines are recommended for less than 2300 mg per day of sodium for those individuals older than two years and less then 1500 mg per day for certain high-risk groups including African-Americans, hypertensive patients, patients with diabetes, patients with chronic kidney disease, and in patients older than 50 years (USDA).
More than 90% of US adults consume more than 2300 mg of sodium per day.
Among high-risk subgroups of adults more than 98% consume more than 1500 mg of sodium per day.
Links exist between dietary sodium to high blood pressure, stroke, and cardiovascular disease, however effects on blood pressure cannot always be separated from the effects of total dietary modification and effects of other electrolytes.
Very low sodium intake may be related to adverse affects on lipids, insulin resistance, renin-aldosterone levels and may increase the risk of cardiovascular disease and stroke.
Salt reduction below 6 gm/d activates the salt conserving hormonal system, renin and aldosterone, the stress hormones adrenalin and noradrenalin, and increases fatty substances, cholesterol and triglyceride, in the blood.Finally, recent observations in general populations indicate that a low salt intake is associated with increased mortality.
Sodium intake has not declined since 1999.
Excess sodium intake is prevalent in all demographic and chronic disease groups.
Adherence to US Department of agriculture guidelines is less than 10% in all high-risk subgroups.
Total caloric intake is the strongest predictor of sodium intake.
People who habitually consume more sodium find that foods tasted less salty than those who consumed less sodium.
Most adults of middle age and older with high baseline sodium intake experience blood pressure lowering during a very low sodium, high potassium, and high calcium diet, versus a very high sodium diet.
Blood pressure response to sodium intake may be more of a spectrum than a binary threshold with the vast majority of middle age and older adults with high baseline sodium intake experiencing blood pressure lowering during a very low sodium, high potassium and high calcium diet versus high sodium diet independent of hypertension, status and antihypertensive medication use.