High Potassium Intake Linked With Lower Risk Of Stroke, Especially Ischemic Stroke

Susanna C. Larsson, Ph.D.

Researchers at Karolinska Institutet in Stockholm have found that dietary potassium intake is inversely associated with risk of stroke, in particular ischemic stroke. A higher intake of potassium (1000 mg) compared to a lower intake was associated with as much as 11 percent reduction in the ischemic stroke risk, 5 percent reduction in intracerebral hemorrhage, but 8 percent increase in the risk of subarachnoid hemorrhage. The study was based on data from prospective studies of 268,276 participants with 8695 cases of stroke reported in Pubmed database from Januar 1966 through March 2011.

 

Larsson SC, Orsini N, Wolk A.

Dietary Potassium Intake and Risk of Stroke: A Dose-Response Meta-Analysis of Prospective Studies.
Stroke. 2011 Jul 28. [Epub ahead of print]


Abstract

Background and Purpose:
Potassium intake has been inconsistently associated with risk of stroke. Our aim was to conduct a meta-analysis of prospective studies to assess the relation between potassium intake and stroke risk.

Methods:
Pertinent studies were identified by a search of PubMed from January 1966 through March 2011 and by reviewing the reference lists of retrieved articles. We included prospective studies that reported relative risks with 95% CIs of stroke for ≥3 categories of potassium intake or for potassium intake analyzed as a continuous variable. Study-specific results were pooled using a random-effects model.

Results:
Ten independent prospective studies, with a total of 8695 stroke cases and 268 276 participants, were included in the meta-analysis. We observed a statistically significant inverse association between potassium intake and risk of stroke. For every 1000-mg/day increase in potassium intake, the risk of stroke decreased by 11% (pooled relative risk, 0.89; 95% CI, 0.83 to 0.97). In the 5 studies that reported results for stroke subtypes, the pooled relative risks were 0.89 (95% CI, 0.81 to 0.97) for ischemic stroke, 0.95 (95% CI, 0.83 to 1.09) for intracerebral hemorrhage, and 1.08 (95% CI, 0.92 to 1.27) for subarachnoid hemorrhage.

Conclusions:
Dietary potassium intake is inversely associated with risk of stroke, in particular ischemic stroke.

 

Magnesium Rich Foods

Food Sources of Magnesium ranked by milligrams of magnesium per standard amount; also calories in the standard amount. (All are  10% of RDA for adult men, which is 420 mg/day.)

Food, Standard Amount

Magnesium (mg)

Calories

Pumpkin and squash seed kernels, roasted, 1 oz

151

148

Brazil nuts, 1 oz

107

186

Bran ready-to-eat cereal (100%), ~1 oz

103

74

Halibut, cooked, 3 oz

91

  119

Quinoa, dry, ¼ cup

89

159

Spinach, canned, ½ cup

81

25

Almonds, 1 oz

78

164

Spinach, cooked from fresh, ½ cup

78

  20

Buckwheat flour, ¼ cup

75

101

Cashews, dry roasted, 1 oz

74

163

Soybeans, mature, cooked, ½ cup

74

  149

Pine nuts, dried, 1 oz

71

191

Mixed nuts, oil roasted, with peanuts, 1 oz

67

175

White beans, canned, ½ cup

67

154

Pollock, walleye, cooked, 3 oz

62

96

Black beans, cooked, ½ cup

60

  114

Bulgur, dry, ¼ cup

57

120

Oat bran, raw, ¼ cup

55

58

Soybeans, green, cooked, ½ cup

54

  127

Tuna, yellowfin, cooked, 3 oz

54

  118

Artichokes (hearts), cooked, ½ cup

50

  42

Peanuts, dry roasted, 1 oz

50

166

Lima beans, baby, cooked from frozen, ½ cup

50

  95

Beet greens, cooked, ½ cup

49

19

Navy beans, cooked, ½ cup

48

127

Tofu, firm, prepared with nigaria , ½ cup

47

  88

Okra, cooked from frozen, ½ cup

47

  26

Soy beverage, 1 cup

47

127

Cowpeas, cooked, ½ cup

46

100

Hazelnuts, 1 oz

46

178

Oat bran muffin, 1 oz

45

77

Great northern beans, cooked, ½ cup

44

104

Oat bran, cooked, ½ cup

44

44

Buckwheat groats, roasted, cooked, ½ cup

43

78

Brown rice, cooked, ½ cup

42

108

Haddock, cooked, 3 oz

42

95

a Calcium sulfate and magnesium chloride.

Source: Nutrient values from Agricultural Research Service (ARS) Nutrient Database for Standard Reference, Release 17. Foods are from ARS single nutrient reports, sorted in descending order by nutrient content in terms of common household measures. Food items and weights in the single nutrient reports are adapted from those in 2002 revision of USDA Home and Garden Bulletin No. 72, Nutritive Value of Foods. Mixed dishes and multiple preparations of the same food item have been omitted from this table.

Potassium Rich Foods

Food Sources of Potassium ranked by milligrams of potassium per standard amount, also showing calories in the standard amount. (The AI for adults is 4,700 mg/day potassium.)

Food, Standard Amount

Potassium (mg)

Calories

Sweetpotato, baked, 1 potato (146 g)

694

131

Tomato paste, ¼ cup

664

54

Beet greens, cooked, ½ cup

655

19

Potato, baked, flesh, 1 potato (156 g)

610

145

White beans, canned, ½ cup

595

153

Yogurt, plain, non-fat, 8-oz container

579

127

Tomato puree, ½ cup

549

48

Clams, canned, 3 oz

534

126

Yogurt, plain, low-fat, 8-oz container

531

143

Prune juice, ¾ cup

530

136

Carrot juice, ¾ cup

517

71

Blackstrap molasses, 1 Tbsp

498

47

Halibut, cooked, 3 oz

490

119

Soybeans, green, cooked, ½ cup

485

127

Tuna, yellowfin, cooked, 3 oz

484

118

Lima beans, cooked, ½ cup

484

104

Winter squash, cooked, ½ cup

448

40

Soybeans, mature, cooked, ½ cup

443

149

Rockfish, Pacific, cooked, 3 oz

442

103

Cod, Pacific, cooked, 3 oz

439

89

Bananas, 1 medium

422

105

Spinach, cooked, ½ cup

419

21

Tomato juice, ¾ cup

417

31

Tomato sauce, ½ cup

405

39

Peaches, dried, uncooked, ¼ cup

398

96

Prunes, stewed, ½ cup

398

133

Milk, non-fat, 1 cup

382

83

Pork chop, center loin, cooked, 3 oz

382

197

Apricots, dried, uncooked, ¼ cup

  378

78

Rainbow trout, farmed, cooked, 3 oz

375

144

Pork loin, center rib (roasts), lean, roasted, 3 oz

371

190

Buttermilk, cultured, low-fat, 1 cup

370

98

Cantaloupe, ¼ medium

368

47

1%-2% milk, 1 cup

366

102-122

Honeydew melon, 1/8 medium

365

58

Lentils, cooked, ½ cup

365

115

Plantains, cooked, ½ cup slices

358

90

Kidney beans, cooked, ½ cup

358

112

Orange juice, ¾ cup

355

85

Split peas, cooked, ½ cup

355

116

Yogurt, plain, whole milk, 8 oz container

352

138

Source: Nutrient values from Agricultural Research Service (ARS) Nutrient Database for Standard Reference, Release 17. Foods are from ARS single nutrient reports, sorted in descending order by nutrient content in terms of common household measures. Food items and weights in the single nutrient reports are adapted from those in 2002 revision of USDA Home and Garden Bulletin No. 72, Nutritive Value of Foods. Mixed dishes and multiple preparations of the same food item have been omitted from this table. 

High Sodium, Low Potassium Diet Linked to Increased Risk of Death

Change in Americans’ diet necessary to lower risk:

Americans who eat a diet high in sodium and low in potassium have a 50 percent increased risk of death from any cause, and about twice the risk of death from heart attacks, according to a study published in the Archives of Internal Medicine. The study was conducted by researchers at the Centers for Disease Control and Prevention, Emory University and Harvard University.

This is the first study to examine, using a nationally representative sample, the association between mortality and people’s usual intake of sodium and potassium. The study analyzed data from the National Health and Nutrition Examination Survey (NHANES), a survey designed to assess the health and nutritional status of adults in the United States. Usual intake of sodium and potassium is based on dietary recall.

“The study’s findings are particularly troubling because U.S. adults consume an average of 3,300 milligrams of sodium per day, more than twice the current recommended limit for most Americans,” said Elena Kuklina, M.D., Ph.D., an investigator on the study and a nutritional epidemiologist with CDC’s Division for Heart Disease and Stroke Prevention. “This study provides further evidence to support current public health recommendations to reduce sodium levels in processed foods, given that nearly 80 percent of people’s sodium intake comes from packaged and restaurant foods. Increasing potassium intake may have additional health benefits.”

The 2010 Dietary Guidelines for Americans recommends limiting intake of sodium to 1,500 milligrams per day for people 51 and older, African Americans, and those who have high blood pressure, diabetes, or chronic kidney disease—about half the U.S. population ages 2 and older. The dietary guidelines recommend that all other people consume less than 2,300 milligrams of sodium per day. In addition, the guidelines recommend that people choose more potassium-rich foods, advising 4,700 milligrams of potassium per day.

Sodium, primarily consumed as salt (sodium chloride), is commonly added to many processed and restaurant foods, while potassium is naturally present in many fresh foods. For example, cheese, processed meats, breads, soups, fast foods, and pastries tend to have more sodium than potassium. Yogurt, milk, fruits and vegetables tend to have less sodium and more potassium. Potassium-rich fruits and vegetables include leafy greens, such as spinach and collards, grapes, blackberries, carrots, potatoes and citrus fruits such as oranges and grapefruit.

In general, people who reduce their sodium consumption, increase their potassium consumption, or do both, benefit from improved blood pressure and reduce their risk for developing other serious health problems. Adults can improve their health by knowing recommended limits for daily sodium intake, choosing foods like fresh or frozen fruits and vegetables, and unprocessed or minimally processed fish, meat or poultry, low-fat milk or plain yogurt, asking for foods with no or low salt at restaurants, and reading the nutrition labels of foods before purchasing can improve health for all adults.