So much attention is given to the association of sodium with high blood pressure that potassium often gets overlooked. Data suggest, however, that low potassium, a condition called hypokalemia, is as problematic for high blood pressure as sodium. Potassium plays a vital role in fluid balance and heart and muscle function. Although study results have been mixed, several factors may help identify your risk for low potassium levels and high blood pressure. The recommended daily intake for potassium is 2,000 mg for adults.
African Americans
A large study, involving 3,300 participants, revealed a strong association between African-Americans, low potassium levels and hypertension. The study, published in the November 2008 issue of the "American Society of Nephrology," analyzed data from the Dallas Heart Study and found that lower potassium levels correlated with high blood pressure -- and was a stronger predictor than sodium levels. This was especially true for African-Americans. The participants provided urine samples and reported dietary habits; the data showed that African-Americans consistently ate a low-potassium diet. This data also led researchers to a possible genetic connection that may influence a potassium-hypertension correlation. The authors said that a follow-up study investigating genetics, the control of dietary potassium intake and blood pressure response is to follow.
Low-Sodium Vegetable Juice
A daily low-sodium vegetable juice may help maintain potassium levels in combination with fruit and vegetable consumption. A 2010 study published in "Nutrition Journal" investigated the use of a low-calorie, low-sodium vegetable juice in 81 individuals with a combination of health conditions such as insulin resistance, high cholesterol, high blood pressure and obesity. The participants were randomly divided into groups receiving 8-oz. of juice, 16-oz., or no juice, for 12 weeks, in combination with a reduced-calorie diet. The groups consuming vegetable juice lost more weight and had higher levels of potassium than the non-juice groups, but despite counseling, none of the groups increased their consumption of fruits and vegetables. The authors state that the juice increased potassium levels, but the lack of vegetable and fruit consumption may have prevented a positive blood pressure response. Other health conditions may have presented limitations for lowering blood pressure.
Black Licorice
An emergency room case study published in the December 2009 issue of "Clinical Chemistry" involved a woman with hypertension and excessive potassium loss. The patient reported routine herb use including black licorice oil, which contains glycyrrhizin, an FDA-approved sweetener used in candy. Large doses of glycyrrhizin are known to interfere with normal metabolism, causing both hypokalemia and hypertension. The author reports a recommendation of an upper limit for glycyrrhizin consumption of 100 mg daily; however, some licorice oils may provide 200 to 800 mg per dose. The patient was advised to discontinue use of licorice oil and prescribed daily oral potassium supplements.
Careful label and ingredient investigation is recommended for licorice flavoring, oil, extracts, powdered licorice root or glycyrrhizin consumption. Consult your physician for more information about your personal risk of hypokalemia from licorice consumption.
Tips
Although small individual clinical trials elicit varying results regarding potassium's role in hypertension, an analysis of all available trials reveals that adequate potassium, and low sodium, result in healthy blood pressure readings. A paper published in the November 2010 issue of the "Indian Journal of Medical Research" reports that this multi-study analysis also revealed that black patients respond better to potassium's effect on blood pressure than white patients. The authors recommend dietary intake for raising potassium levels, and managing blood pressure, over prescription use. Food sources of potassium include bananas, potatoes, citrus juice, avocados, tomatoes, lima beans, chicken, cantaloupes, salmon, cod and flounder. Medications and health conditions can also interfere with potassium levels, so consult your doctor for evaluation.
References
- EurekAlert.org; Low Potassium Linked to High Blood Pressure; November 2008
- University of Maryland Medical Center; Potassium; May 2009
- "Nutrition Journal"; Weight Loss in Individuals with Metabolic Syndrome Given DASH Diet Counseling When Provided a Low-Sodium Vegetable Juice: A Randomized Controlled Trial; Sonia F. Shenoy, et al.; February 2010
- "Indian Journal of Medical Research"; Strategies for Initial Management of Hypertension; Rejeev Gupta and Soneil Guptha; November 2010
- "Clinical Chemistry"; Too Much of a Good Thing: A Woman with Hypertension and Hypokalemia; Sean C. Murphy et al.; December 2009
