Salt & Potassium
Does salt raise blood pressure?
Salt is sodium chloride. It is the sodium part that affects your blood pressure: the more sodium you eat, the higher your blood pressure. In one study of more than 400 people (57% were women), those who followed a low sodium DASH diet—one rich in fruits, vegetables, and low-fat dairy products—lowered their blood pressure.77 The fall in blood pressure is steeper when your sodium intake is less than 2,300 milligrams per day.78 In the DASH study, the greatest benefits were seen in people with high blood pressure, African Americans, women, and people 45 years or older.79 Compared with an average American diet high in sodium, the low sodium DASH diet reduced systolic blood pressure (the top number) by 10.5 points in women compared with 6.8 points in men. There is a wide variation in how people respond to sodium – it may raise blood pressure far more in one person than in the next. Cutting down on sodium can lower your blood pressure even if you are already on blood pressure medication.80
Does cutting sodium prevent high blood pressure and heart disease?
A low sodium diet can prevent high blood pressure. A study of more than 2,000 overweight men and women showed that those who cut sodium, lost weight, or did both cut their risk of developing high blood pressure by around 20%.81
There seems to be a link between a diet high in sodium and the risk of developing heart disease.82 The National Health and Nutrition Examination Study followed more than 2,600 overweight people (65% were women) for 19 years and found that increasing the amount of sodium by 2,300 milligrams per day increased the risk of dying from heart disease by 44%.83 However, there have been no studies to show if the reverse is true and it's not known whether cutting salt will lower your risk of dying from heart disease.
How much sodium should I get?
Dietary guidelines recommend no more than 6 grams of salt per day (a heaping teaspoon) or 2,300 milligrams of sodium.2, 3 You should go even lower if you are trying to reduce your blood pressure: 1,500 milligrams of sodium or 3.8 grams of salt per day.84 On average, Americans consume 3,375 milligrams of sodium per day.19 One quarter of adult men get more than 5,200 mg per day and one quarter of adult women consume more than 3,500 mg per day. Most of the sodium in our diet (about 75%) comes from processed foods; discretionary salt makes up 11% (5% from cooking and 6% added at the table).85 Cutting down on sodium can lower your taste preference for salty food within 8 to 12 weeks.86, 87
Does potassium lower blood pressure?
Yes. Potassium is a kind of anti-sodium; the more you eat the lower your blood pressure.88 In addition, potassium blunts the blood pressure-raising effects of a high sodium diet.89 The DASH diet is high in potassium (4.7 grams per day) largely from fruits and vegetables, and it has been shown to lower blood pressure in men and women.59 The blood pressure-lowering effects of potassium vary from person to person and appear to be greater in people with high blood pressure and in black men and women.84
How much potassium should I get?
You should aim for 4.7 grams of potassium per day from foods such as fruits and vegetables rather than supplements.84 It is estimated that 10% of men and less than 1% of women get this amount of potassium. Most men get 2.9 to 3.2 grams and most women get 2.1 to 2.3 grams per day. Blood pressure medications including ACE inhibitors, angiotensin receptor blockers, and potassium sparing diuretics can impair your body's ability to get rid of excess potassium (in urine). If you are taking these medications, you should include no more than 4.7 grams of potassium in your daily diet.84